STATISTICAL MODELLING OF STAFF SURVIVAL TIME IN SERVICE AT CHUKA UNIVERSITY

IMPORTING DATA

Mydata <- read.csv("C:/Users/user/Desktop/RESEARCH PROJECT WAKA ANALYSIS/staff_survival.data2.csv")
View(Mydata)
attach(Mydata)

Display the first few rows of the dataset

head(Mydata)
##   Serial_No Gender Age_Bracket     Marital_Status Terms_of_Employment Job_Group
## 1         1   Male       36-50             Single           Permanent        10
## 2         2 Female       26-35             Single            Contract         7
## 3         3   Male       36-50            Married           Permanent         1
## 4         4 Female       36-50            Married            Contract        11
## 5         5 Female       36-50            Married            Contract         2
## 6         6   Male       51-75 Divorced/Separated           Permanent        11
##   Employment_Status Level_of_Education Academic_Designation
## 1                 0             Degree   Non-teaching staff
## 2                 0            Diploma   Non-teaching staff
## 3                 0        Certificate   Non-teaching staff
## 4                 0               Ph.D       Teaching staff
## 5                 0        Certificate   Non-teaching staff
## 6                 1               Ph.D       Teaching staff
##   Employment_Start_Date Employment_End_Date   Exit_Type time
## 1             12/2/2021                <NA>        <NA>  759
## 2             5/15/2023                <NA>        <NA>  230
## 3             5/31/2021                <NA>        <NA>  944
## 4             2/23/2013                <NA>        <NA> 3963
## 5             5/13/2016                <NA>        <NA> 2788
## 6              7/6/2014          10/13/2021 Resignation 2656

Display the last few rows of the dataset

tail(Mydata)
##     Serial_No Gender Age_Bracket     Marital_Status Terms_of_Employment
## 595       595   Male       36-50            Married            Contract
## 596       596 Female       36-50            Married            Contract
## 597       597   Male       51-75            Married           Permanent
## 598       598   Male       36-50 Divorced/Separated           Permanent
## 599       599 Female       18-25            Married            Contract
## 600       600   Male       36-50            Married            Contract
##     Job_Group Employment_Status Level_of_Education Academic_Designation
## 595         8                 1            Diploma   Non-teaching staff
## 596         3                 0        Certificate   Non-teaching staff
## 597         1                 0        Certificate   Non-teaching staff
## 598        13                 0            Masters       Teaching staff
## 599        12                 0               Ph.D       Teaching staff
## 600        12                 0               Ph.D       Teaching staff
##     Employment_Start_Date Employment_End_Date   Exit_Type time
## 595            10/28/2017           5/10/2020 Resignation  925
## 596             6/17/2021                <NA>        <NA>  927
## 597            11/12/2021                <NA>        <NA>  779
## 598             3/17/2022                <NA>        <NA>  654
## 599             8/19/2019                <NA>        <NA> 1595
## 600             3/19/2019                <NA>        <NA> 1748

Set up the script to remove scientific notation

Use the command below to ensure that the output values are not written in scientific notation.

options(scipen=999)

Activate the necessary packages

library(survival)
library(ggplot2)
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
library(tidyverse)
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ forcats   1.0.0     ✔ stringr   1.5.1
## ✔ lubridate 1.9.3     ✔ tibble    3.2.1
## ✔ purrr     1.0.2     ✔ tidyr     1.3.1
## ✔ readr     2.1.5
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag()    masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
library(survminer)
## Loading required package: ggpubr
## 
## Attaching package: 'survminer'
## 
## The following object is masked from 'package:survival':
## 
##     myeloma
library(magrittr)
## 
## Attaching package: 'magrittr'
## 
## The following object is masked from 'package:purrr':
## 
##     set_names
## 
## The following object is masked from 'package:tidyr':
## 
##     extract
library(ggpubr)
library(stargazer)
## 
## Please cite as: 
## 
##  Hlavac, Marek (2022). stargazer: Well-Formatted Regression and Summary Statistics Tables.
##  R package version 5.2.3. https://CRAN.R-project.org/package=stargazer
library(ggfortify)
library(simsurv)

Read variable name

names(Mydata)
##  [1] "Serial_No"             "Gender"                "Age_Bracket"          
##  [4] "Marital_Status"        "Terms_of_Employment"   "Job_Group"            
##  [7] "Employment_Status"     "Level_of_Education"    "Academic_Designation" 
## [10] "Employment_Start_Date" "Employment_End_Date"   "Exit_Type"            
## [13] "time"

####Exploratory and Non parametric statistics

hist (Mydata$time, xlab="survival time", ylab="No. of staff", main="Distribution of the survival 
times of staff at Chuka University")

KM CURVES

#1.Survival distribution of Staff classified by gender

KM1<-survfit (Surv (time, Employment_Status) ~ Gender, data = Mydata)

Summaries of the model

KM1
## Call: survfit(formula = Surv(time, Employment_Status) ~ Gender, data = Mydata)
## 
##                 n events median 0.95LCL 0.95UCL
## Gender=Female 234     62     NA    3183      NA
## Gender=Male   366    107     NA    3262      NA
ggsurvplot(KM1, 
           conf.int = TRUE,         # Show confidence intervals
           pval = TRUE,             # Show p-value
           risk.table = TRUE,       # Show risk table
           ggtheme = theme_minimal())

Model summary

Summary1<-summary(KM1)
Summary1
## Call: survfit(formula = Surv(time, Employment_Status) ~ Gender, data = Mydata)
## 
##                 Gender=Female 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    89    228       1    0.996 0.00438        0.987        1.000
##   117    225       1    0.991 0.00620        0.979        1.000
##   122    224       1    0.987 0.00759        0.972        1.000
##   123    223       1    0.982 0.00875        0.965        1.000
##   182    219       1    0.978 0.00979        0.959        0.997
##   238    216       1    0.973 0.01074        0.952        0.995
##   262    214       1    0.969 0.01162        0.946        0.992
##   283    210       1    0.964 0.01244        0.940        0.989
##   286    209       1    0.960 0.01321        0.934        0.986
##   293    208       1    0.955 0.01393        0.928        0.983
##   367    206       1    0.950 0.01461        0.922        0.979
##   397    205       1    0.946 0.01526        0.916        0.976
##   426    202       1    0.941 0.01589        0.910        0.973
##   470    197       1    0.936 0.01651        0.904        0.969
##   492    195       1    0.931 0.01711        0.898        0.966
##   512    194       1    0.927 0.01768        0.893        0.962
##   568    193       1    0.922 0.01823        0.887        0.958
##   704    188       1    0.917 0.01878        0.881        0.954
##   714    186       1    0.912 0.01932        0.875        0.951
##   772    182       1    0.907 0.01985        0.869        0.947
##   850    179       1    0.902 0.02037        0.863        0.943
##   939    175       1    0.897 0.02090        0.857        0.939
##   969    173       1    0.892 0.02141        0.851        0.935
##  1015    171       1    0.886 0.02191        0.844        0.930
##  1072    167       1    0.881 0.02241        0.838        0.926
##  1081    166       1    0.876 0.02290        0.832        0.922
##  1150    162       1    0.870 0.02339        0.826        0.917
##  1163    161       1    0.865 0.02386        0.819        0.913
##  1192    159       1    0.859 0.02432        0.813        0.908
##  1205    158       1    0.854 0.02477        0.807        0.904
##  1274    150       1    0.848 0.02525        0.800        0.899
##  1330    147       1    0.843 0.02573        0.794        0.895
##  1360    144       1    0.837 0.02621        0.787        0.890
##  1511    133       1    0.830 0.02675        0.780        0.885
##  1590    126       1    0.824 0.02734        0.772        0.879
##  1681    120       1    0.817 0.02796        0.764        0.874
##  1818    112       1    0.810 0.02865        0.755        0.868
##  1820    111       1    0.802 0.02930        0.747        0.862
##  1879    108       1    0.795 0.02996        0.738        0.856
##  1958    107       1    0.788 0.03059        0.730        0.850
##  1992    104       1    0.780 0.03122        0.721        0.844
##  2017    103       1    0.772 0.03182        0.712        0.837
##  2052    100       1    0.765 0.03242        0.704        0.831
##  2054     99       1    0.757 0.03300        0.695        0.824
##  2080     98       1    0.749 0.03356        0.686        0.818
##  2090     96       1    0.741 0.03410        0.677        0.811
##  2109     94       1    0.734 0.03464        0.669        0.805
##  2134     93       1    0.726 0.03516        0.660        0.798
##  2147     92       1    0.718 0.03565        0.651        0.791
##  2267     89       1    0.710 0.03615        0.642        0.784
##  2403     77       1    0.700 0.03683        0.632        0.777
##  2416     76       1    0.691 0.03748        0.622        0.769
##  2470     73       1    0.682 0.03815        0.611        0.761
##  2552     69       1    0.672 0.03885        0.600        0.753
##  2657     63       1    0.661 0.03967        0.588        0.744
##  2751     58       1    0.650 0.04059        0.575        0.734
##  2929     49       1    0.637 0.04188        0.560        0.724
##  3079     44       1    0.622 0.04335        0.543        0.713
##  3094     42       1    0.607 0.04478        0.526        0.702
##  3178     38       1    0.591 0.04636        0.507        0.690
##  3183     37       1    0.575 0.04779        0.489        0.677
##  3226     34       1    0.558 0.04929        0.470        0.664
## 
##                 Gender=Male 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    365       1    0.997 0.00274        0.992        1.000
##    41    364       1    0.995 0.00386        0.987        1.000
##    66    361       1    0.992 0.00473        0.983        1.000
##    70    360       1    0.989 0.00546        0.978        1.000
##   108    358       1    0.986 0.00611        0.974        0.998
##   115    356       1    0.983 0.00669        0.970        0.997
##   131    354       1    0.981 0.00722        0.967        0.995
##   203    350       1    0.978 0.00773        0.963        0.993
##   212    348       1    0.975 0.00820        0.959        0.991
##   217    347       1    0.972 0.00865        0.955        0.989
##   232    343       1    0.969 0.00907        0.952        0.987
##   255    341       2    0.964 0.00987        0.945        0.983
##   257    339       1    0.961 0.01024        0.941        0.981
##   274    337       1    0.958 0.01060        0.938        0.979
##   300    335       1    0.955 0.01095        0.934        0.977
##   304    334       1    0.952 0.01128        0.930        0.975
##   321    330       1    0.949 0.01161        0.927        0.972
##   351    326       1    0.947 0.01194        0.923        0.970
##   361    324       1    0.944 0.01225        0.920        0.968
##   371    322       1    0.941 0.01256        0.916        0.966
##   372    321       1    0.938 0.01286        0.913        0.963
##   376    319       1    0.935 0.01315        0.909        0.961
##   395    316       1    0.932 0.01344        0.906        0.959
##   399    315       1    0.929 0.01372        0.902        0.956
##   466    312       1    0.926 0.01399        0.899        0.954
##   482    310       1    0.923 0.01426        0.895        0.951
##   493    309       1    0.920 0.01452        0.892        0.949
##   527    308       1    0.917 0.01478        0.888        0.946
##   536    306       1    0.914 0.01503        0.885        0.944
##   540    305       1    0.911 0.01528        0.882        0.941
##   575    302       1    0.908 0.01552        0.878        0.939
##   582    300       1    0.905 0.01576        0.875        0.936
##   613    299       1    0.902 0.01600        0.871        0.934
##   674    292       1    0.899 0.01624        0.868        0.931
##   691    287       1    0.896 0.01648        0.864        0.929
##   700    286       1    0.893 0.01672        0.860        0.926
##   720    283       1    0.889 0.01696        0.857        0.923
##   737    279       1    0.886 0.01719        0.853        0.921
##   753    278       1    0.883 0.01742        0.850        0.918
##   798    272       1    0.880 0.01766        0.846        0.915
##   803    271       1    0.877 0.01789        0.842        0.912
##   821    270       1    0.873 0.01812        0.838        0.910
##   839    268       1    0.870 0.01834        0.835        0.907
##   857    265       1    0.867 0.01856        0.831        0.904
##   895    260       1    0.863 0.01879        0.827        0.901
##   914    259       1    0.860 0.01901        0.824        0.898
##   925    256       1    0.857 0.01923        0.820        0.895
##   935    254       1    0.853 0.01945        0.816        0.892
##   944    252       1    0.850 0.01966        0.812        0.889
##   998    244       1    0.846 0.01989        0.808        0.886
##  1113    235       1    0.843 0.02013        0.804        0.883
##  1120    234       1    0.839 0.02036        0.800        0.880
##  1161    230       1    0.836 0.02060        0.796        0.877
##  1165    228       1    0.832 0.02083        0.792        0.874
##  1166    227       1    0.828 0.02106        0.788        0.871
##  1184    224       1    0.825 0.02129        0.784        0.867
##  1198    222       1    0.821 0.02151        0.780        0.864
##  1201    221       1    0.817 0.02173        0.776        0.861
##  1225    215       1    0.813 0.02196        0.771        0.858
##  1264    213       1    0.810 0.02219        0.767        0.854
##  1271    212       1    0.806 0.02241        0.763        0.851
##  1308    209       1    0.802 0.02263        0.759        0.847
##  1353    205       1    0.798 0.02286        0.754        0.844
##  1356    204       1    0.794 0.02308        0.750        0.841
##  1393    200       1    0.790 0.02330        0.746        0.837
##  1411    199       1    0.786 0.02352        0.741        0.834
##  1429    198       1    0.782 0.02373        0.737        0.830
##  1444    195       1    0.778 0.02395        0.733        0.827
##  1490    192       1    0.774 0.02416        0.728        0.823
##  1591    186       1    0.770 0.02439        0.724        0.819
##  1662    179       1    0.766 0.02463        0.719        0.815
##  1689    177       1    0.761 0.02487        0.714        0.812
##  1697    176       1    0.757 0.02510        0.709        0.808
##  1699    175       1    0.753 0.02533        0.705        0.804
##  1723    173       1    0.748 0.02555        0.700        0.800
##  1725    172       1    0.744 0.02577        0.695        0.796
##  1811    166       1    0.739 0.02600        0.690        0.792
##  2054    154       1    0.735 0.02627        0.685        0.788
##  2186    143       1    0.730 0.02659        0.679        0.784
##  2267    138       1    0.724 0.02691        0.673        0.779
##  2317    134       2    0.713 0.02758        0.661        0.770
##  2358    129       1    0.708 0.02791        0.655        0.765
##  2434    121       1    0.702 0.02829        0.649        0.760
##  2453    120       1    0.696 0.02865        0.642        0.755
##  2460    119       1    0.690 0.02900        0.636        0.750
##  2462    118       1    0.684 0.02934        0.629        0.744
##  2489    117       1    0.679 0.02967        0.623        0.739
##  2523    116       1    0.673 0.02998        0.617        0.734
##  2581    110       1    0.667 0.03033        0.610        0.729
##  2595    109       1    0.661 0.03066        0.603        0.723
##  2653    105       1    0.654 0.03100        0.596        0.718
##  2656    104       1    0.648 0.03134        0.589        0.712
##  2759    100       1    0.641 0.03169        0.582        0.707
##  2850     94       1    0.635 0.03208        0.575        0.701
##  2893     89       1    0.628 0.03250        0.567        0.695
##  2918     85       1    0.620 0.03295        0.559        0.688
##  3001     76       1    0.612 0.03351        0.550        0.681
##  3007     75       1    0.604 0.03404        0.541        0.674
##  3029     73       1    0.596 0.03456        0.532        0.667
##  3069     70       1    0.587 0.03510        0.522        0.660
##  3136     64       1    0.578 0.03573        0.512        0.652
##  3262     52       1    0.567 0.03673        0.499        0.644
##  3271     51       1    0.556 0.03765        0.487        0.635
##  3344     45       1    0.543 0.03879        0.472        0.625
##  3566     30       1    0.525 0.04151        0.450        0.613

###Log Rank test: Comparison of survival curves ## h0:There is no difference in survival experience across the Gender

log_rank_test <- survdiff(Surv(time, Employment_Status) ~ Gender, data = Mydata)
log_rank_test
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Gender, data = Mydata)
## 
##                 N Observed Expected (O-E)^2/E (O-E)^2/V
## Gender=Female 234       62     66.5     0.311     0.514
## Gender=Male   366      107    102.5     0.202     0.514
## 
##  Chisq= 0.5  on 1 degrees of freedom, p= 0.5

##PLOT THE CURVE

plot (KM1,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per the Gender", col=c (2, 4)) 
legend("topright",c("F","M"),col=c(2,4),lty=c(1,2),ncol=2,cex=0.6)

#1.Survival distribution of Staff classified by age

KM2<-survfit (Surv (time, Employment_Status) ~ Age_Bracket, data = Mydata)

##Summary of the model

KM2
## Call: survfit(formula = Surv(time, Employment_Status) ~ Age_Bracket, 
##     data = Mydata)
## 
##                     n events median 0.95LCL 0.95UCL
## Age_Bracket=18-25  47     17   3007    2453      NA
## Age_Bracket=26-35 126     39   3344    3029      NA
## Age_Bracket=36-50 299     72     NA      NA      NA
## Age_Bracket=51-75 128     41     NA    2751      NA

##Model Summary

Summary2<-summary(KM2)
Summary2
## Call: survfit(formula = Surv(time, Employment_Status) ~ Age_Bracket, 
##     data = Mydata)
## 
##                 Age_Bracket=18-25 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    41     47       1    0.979  0.0210        0.938        1.000
##    66     46       1    0.957  0.0294        0.901        1.000
##   262     44       1    0.936  0.0359        0.868        1.000
##   470     42       1    0.913  0.0414        0.836        0.998
##   493     41       1    0.891  0.0460        0.805        0.986
##   527     40       1    0.869  0.0500        0.776        0.972
##   772     38       1    0.846  0.0536        0.747        0.958
##   850     36       1    0.822  0.0570        0.718        0.942
##   857     35       1    0.799  0.0601        0.690        0.926
##   998     34       1    0.775  0.0627        0.662        0.909
##  1725     21       1    0.739  0.0698        0.614        0.889
##  2017     17       1    0.695  0.0780        0.558        0.866
##  2267     16       1    0.652  0.0844        0.506        0.840
##  2453     14       1    0.605  0.0903        0.452        0.811
##  2552     13       1    0.559  0.0946        0.401        0.778
##  3007      7       1    0.479  0.1097        0.306        0.750
##  3094      5       1    0.383  0.1226        0.205        0.717
## 
##                 Age_Bracket=26-35 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    70    125       1    0.992 0.00797        0.977        1.000
##    89    124       1    0.984 0.01122        0.962        1.000
##   117    122       1    0.976 0.01373        0.949        1.000
##   122    121       1    0.968 0.01581        0.937        0.999
##   131    120       1    0.960 0.01761        0.926        0.995
##   203    119       1    0.952 0.01922        0.915        0.990
##   212    118       1    0.944 0.02068        0.904        0.985
##   255    115       1    0.935 0.02207        0.893        0.980
##   257    114       1    0.927 0.02335        0.883        0.974
##   274    113       1    0.919 0.02455        0.872        0.968
##   351    110       1    0.911 0.02571        0.862        0.963
##   361    108       1    0.902 0.02681        0.851        0.956
##   367    107       1    0.894 0.02786        0.841        0.950
##   371    106       1    0.885 0.02884        0.831        0.944
##   395    104       1    0.877 0.02980        0.820        0.937
##   613     99       1    0.868 0.03078        0.810        0.931
##   939     90       1    0.858 0.03192        0.798        0.923
##  1120     87       1    0.849 0.03304        0.786        0.916
##  1150     85       1    0.839 0.03413        0.774        0.908
##  1264     82       1    0.828 0.03521        0.762        0.900
##  1274     81       1    0.818 0.03623        0.750        0.892
##  1360     79       1    0.808 0.03722        0.738        0.884
##  1444     74       1    0.797 0.03828        0.725        0.875
##  1490     73       1    0.786 0.03929        0.713        0.867
##  1511     71       1    0.775 0.04026        0.700        0.858
##  1689     63       1    0.763 0.04146        0.685        0.848
##  1699     62       1    0.750 0.04257        0.671        0.838
##  1723     61       1    0.738 0.04362        0.657        0.829
##  1811     59       1    0.725 0.04463        0.643        0.818
##  1818     58       1    0.713 0.04558        0.629        0.808
##  2109     49       1    0.698 0.04692        0.612        0.797
##  2434     36       1    0.679 0.04946        0.589        0.783
##  2759     32       1    0.658 0.05227        0.563        0.769
##  2918     29       1    0.635 0.05517        0.536        0.753
##  3001     28       1    0.612 0.05767        0.509        0.737
##  3029     27       1    0.590 0.05983        0.483        0.719
##  3079     24       1    0.565 0.06218        0.456        0.701
##  3226     17       1    0.532 0.06682        0.416        0.680
##  3344     14       1    0.494 0.07204        0.371        0.657
## 
##                 Age_Bracket=36-50 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##   108    291       1    0.997 0.00343        0.990        1.000
##   115    288       1    0.993 0.00486        0.984        1.000
##   182    282       1    0.990 0.00598        0.978        1.000
##   217    279       1    0.986 0.00693        0.973        1.000
##   232    277       1    0.982 0.00777        0.967        0.998
##   238    276       1    0.979 0.00852        0.962        0.996
##   286    269       1    0.975 0.00923        0.957        0.994
##   300    268       1    0.972 0.00989        0.952        0.991
##   321    264       1    0.968 0.01051        0.948        0.989
##   372    261       1    0.964 0.01111        0.943        0.986
##   426    256       1    0.960 0.01169        0.938        0.984
##   466    255       1    0.957 0.01223        0.933        0.981
##   482    252       1    0.953 0.01276        0.928        0.978
##   492    250       1    0.949 0.01326        0.923        0.975
##   536    248       1    0.945 0.01375        0.919        0.973
##   568    246       1    0.941 0.01422        0.914        0.970
##   674    241       1    0.938 0.01469        0.909        0.967
##   691    237       1    0.934 0.01515        0.904        0.964
##   700    235       1    0.930 0.01560        0.900        0.961
##   704    234       1    0.926 0.01603        0.895        0.958
##   714    232       1    0.922 0.01645        0.890        0.954
##   737    229       1    0.918 0.01686        0.885        0.951
##   753    228       1    0.914 0.01726        0.880        0.948
##   798    224       1    0.910 0.01766        0.876        0.945
##   803    223       1    0.905 0.01805        0.871        0.942
##   914    217       1    0.901 0.01844        0.866        0.938
##   925    214       1    0.897 0.01883        0.861        0.935
##   935    212       1    0.893 0.01921        0.856        0.931
##   944    211       1    0.889 0.01958        0.851        0.928
##   969    207       1    0.884 0.01995        0.846        0.924
##  1015    202       1    0.880 0.02033        0.841        0.921
##  1072    196       1    0.875 0.02071        0.836        0.917
##  1161    191       1    0.871 0.02110        0.830        0.913
##  1163    190       1    0.866 0.02149        0.825        0.909
##  1165    189       1    0.862 0.02185        0.820        0.906
##  1166    188       1    0.857 0.02221        0.815        0.902
##  1184    187       1    0.853 0.02256        0.809        0.898
##  1192    185       1    0.848 0.02291        0.804        0.894
##  1198    184       1    0.843 0.02324        0.799        0.890
##  1271    173       1    0.838 0.02361        0.793        0.886
##  1308    169       1    0.833 0.02399        0.788        0.882
##  1330    167       1    0.828 0.02436        0.782        0.878
##  1393    162       1    0.823 0.02474        0.776        0.873
##  1411    161       1    0.818 0.02511        0.770        0.869
##  1429    159       1    0.813 0.02547        0.765        0.865
##  1681    147       1    0.808 0.02589        0.758        0.860
##  1820    138       1    0.802 0.02636        0.752        0.855
##  1992    132       1    0.796 0.02685        0.745        0.850
##  2054    130       1    0.790 0.02733        0.738        0.845
##  2080    127       1    0.783 0.02781        0.731        0.840
##  2090    125       1    0.777 0.02829        0.724        0.835
##  2134    123       1    0.771 0.02876        0.716        0.829
##  2147    122       1    0.764 0.02921        0.709        0.824
##  2186    119       1    0.758 0.02966        0.702        0.818
##  2267    116       1    0.751 0.03011        0.695        0.813
##  2317    115       2    0.738 0.03098        0.680        0.802
##  2358    109       1    0.732 0.03142        0.673        0.796
##  2403    105       1    0.725 0.03189        0.665        0.790
##  2460    104       1    0.718 0.03233        0.657        0.784
##  2470    103       1    0.711 0.03276        0.649        0.778
##  2489    102       1    0.704 0.03317        0.642        0.772
##  2581     95       1    0.696 0.03364        0.633        0.765
##  2595     92       1    0.689 0.03412        0.625        0.759
##  2657     88       1    0.681 0.03461        0.616        0.752
##  2850     75       1    0.672 0.03532        0.606        0.745
##  2893     71       1    0.662 0.03607        0.595        0.737
##  3069     58       1    0.651 0.03721        0.582        0.728
##  3178     52       1    0.638 0.03855        0.567        0.719
##  3262     47       1    0.625 0.04005        0.551        0.708
##  3271     45       1    0.611 0.04149        0.535        0.698
##  3566     25       1    0.587 0.04648        0.502        0.685
## 
##                 Age_Bracket=51-75 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    128       1    0.992 0.00778        0.977        1.000
##   123    126       1    0.984 0.01101        0.963        1.000
##   255    123       1    0.976 0.01352        0.950        1.000
##   283    122       1    0.968 0.01560        0.938        0.999
##   293    121       1    0.960 0.01740        0.927        0.995
##   304    120       1    0.952 0.01901        0.916        0.990
##   376    118       1    0.944 0.02049        0.905        0.985
##   397    117       1    0.936 0.02184        0.894        0.980
##   399    116       1    0.928 0.02310        0.884        0.974
##   512    112       1    0.920 0.02433        0.873        0.969
##   540    111       1    0.912 0.02549        0.863        0.963
##   575    110       1    0.903 0.02657        0.853        0.957
##   582    108       1    0.895 0.02761        0.842        0.951
##   720    103       1    0.886 0.02867        0.832        0.944
##   821     99       1    0.877 0.02975        0.821        0.938
##   839     98       1    0.868 0.03076        0.810        0.931
##   895     96       1    0.859 0.03174        0.799        0.924
##  1081     90       1    0.850 0.03279        0.788        0.916
##  1113     89       1    0.840 0.03379        0.776        0.909
##  1201     85       1    0.830 0.03480        0.765        0.901
##  1205     84       1    0.820 0.03577        0.753        0.894
##  1225     83       1    0.810 0.03668        0.742        0.886
##  1353     80       1    0.800 0.03759        0.730        0.878
##  1356     79       1    0.790 0.03846        0.718        0.869
##  1590     71       1    0.779 0.03949        0.705        0.860
##  1591     70       1    0.768 0.04047        0.693        0.852
##  1662     67       1    0.757 0.04145        0.679        0.842
##  1697     66       1    0.745 0.04238        0.666        0.833
##  1879     61       1    0.733 0.04341        0.652        0.823
##  1958     60       1    0.721 0.04437        0.639        0.813
##  2052     56       1    0.708 0.04541        0.624        0.803
##  2054     55       1    0.695 0.04637        0.610        0.792
##  2416     44       1    0.679 0.04793        0.591        0.780
##  2462     41       1    0.663 0.04954        0.572        0.767
##  2523     39       1    0.646 0.05110        0.553        0.754
##  2653     37       1    0.628 0.05261        0.533        0.740
##  2656     36       1    0.611 0.05397        0.514        0.726
##  2751     34       1    0.593 0.05529        0.494        0.712
##  2929     30       1    0.573 0.05686        0.472        0.696
##  3136     25       1    0.550 0.05903        0.446        0.679
##  3183     23       1    0.526 0.06111        0.419        0.661
log_rank_test2 <- survdiff(Surv(time, Employment_Status) ~ Age_Bracket, data = Mydata)
log_rank_test2
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Age_Bracket, 
##     data = Mydata)
## 
##                     N Observed Expected (O-E)^2/E (O-E)^2/V
## Age_Bracket=18-25  47       17     12.3     1.759     1.900
## Age_Bracket=26-35 126       39     34.8     0.513     0.647
## Age_Bracket=36-50 299       72     84.6     1.870     3.749
## Age_Bracket=51-75 128       41     37.3     0.366     0.470
## 
##  Chisq= 4.5  on 3 degrees of freedom, p= 0.2

##Plot of the model

plot (KM2,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per the Age", col=c (2, 4,6,8)) 
legend("topright",c("18-25","26-35","36-50","51-75"),col=c(2,4,6,8),lty=c(1,2),ncol=4,cex=0.6)

#3.Survival distribution of Staff classified by terms of employment

KM3<-survfit (Surv (time, Employment_Status) ~ Terms_of_Employment, data = Mydata)

##summaries of the model

KM3
## Call: survfit(formula = Surv(time, Employment_Status) ~ Terms_of_Employment, 
##     data = Mydata)
## 
##                                 n events median 0.95LCL 0.95UCL
## Terms_of_Employment=Contract  236     65     NA      NA      NA
## Terms_of_Employment=Permanent 364    104     NA    3178      NA

###Model Summary

Summary3<-summary(KM3)
Summary3
## Call: survfit(formula = Surv(time, Employment_Status) ~ Terms_of_Employment, 
##     data = Mydata)
## 
##                 Terms_of_Employment=Contract 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    41    233       1    0.996 0.00428        0.987        1.000
##    89    231       1    0.991 0.00606        0.980        1.000
##   108    230       1    0.987 0.00741        0.973        1.000
##   115    227       1    0.983 0.00856        0.966        1.000
##   131    225       1    0.978 0.00957        0.960        0.997
##   182    224       1    0.974 0.01047        0.954        0.995
##   212    222       1    0.970 0.01131        0.948        0.992
##   238    219       1    0.965 0.01209        0.942        0.989
##   255    217       1    0.961 0.01283        0.936        0.986
##   262    216       1    0.956 0.01352        0.930        0.983
##   274    215       1    0.952 0.01417        0.924        0.980
##   293    213       1    0.947 0.01479        0.919        0.977
##   300    212       1    0.943 0.01538        0.913        0.974
##   304    211       1    0.938 0.01594        0.908        0.970
##   351    207       1    0.934 0.01650        0.902        0.967
##   376    206       1    0.929 0.01703        0.897        0.963
##   399    205       1    0.925 0.01754        0.891        0.960
##   527    201       1    0.920 0.01805        0.886        0.956
##   536    200       1    0.916 0.01853        0.880        0.953
##   575    198       1    0.911 0.01901        0.875        0.949
##   582    197       1    0.906 0.01947        0.869        0.945
##   674    192       1    0.902 0.01993        0.863        0.942
##   720    187       1    0.897 0.02040        0.858        0.938
##   772    181       1    0.892 0.02088        0.852        0.934
##   798    179       1    0.887 0.02135        0.846        0.930
##   821    177       1    0.882 0.02181        0.840        0.926
##   857    174       1    0.877 0.02226        0.834        0.922
##   895    171       1    0.872 0.02272        0.828        0.917
##   925    169       1    0.867 0.02316        0.822        0.913
##   935    166       1    0.861 0.02360        0.816        0.909
##   998    161       1    0.856 0.02405        0.810        0.904
##  1113    157       1    0.851 0.02451        0.804        0.900
##  1161    153       1    0.845 0.02497        0.797        0.895
##  1192    152       1    0.839 0.02542        0.791        0.891
##  1198    151       1    0.834 0.02585        0.785        0.886
##  1201    150       1    0.828 0.02627        0.778        0.881
##  1225    147       1    0.823 0.02669        0.772        0.877
##  1264    146       1    0.817 0.02709        0.766        0.872
##  1330    143       1    0.811 0.02750        0.759        0.867
##  1360    138       1    0.805 0.02792        0.753        0.862
##  1393    134       1    0.799 0.02835        0.746        0.857
##  1444    131       1    0.793 0.02879        0.739        0.852
##  1511    128       1    0.787 0.02922        0.732        0.847
##  1591    121       1    0.781 0.02969        0.725        0.841
##  1697    112       1    0.774 0.03024        0.717        0.835
##  1699    111       1    0.767 0.03076        0.709        0.829
##  1723    110       1    0.760 0.03126        0.701        0.823
##  1725    109       1    0.753 0.03174        0.693        0.818
##  1958    105       1    0.746 0.03223        0.685        0.811
##  2054    103       1    0.738 0.03272        0.677        0.805
##  2080    101       1    0.731 0.03321        0.669        0.799
##  2090     99       1    0.724 0.03368        0.661        0.793
##  2186     93       1    0.716 0.03421        0.652        0.786
##  2267     91       1    0.708 0.03472        0.643        0.779
##  2317     86       1    0.700 0.03528        0.634        0.772
##  2358     83       1    0.691 0.03585        0.625        0.765
##  2403     78       1    0.682 0.03647        0.615        0.758
##  2460     74       1    0.673 0.03713        0.604        0.750
##  2462     73       1    0.664 0.03774        0.594        0.742
##  2581     66       1    0.654 0.03849        0.583        0.734
##  2653     64       1    0.644 0.03922        0.571        0.725
##  2751     60       1    0.633 0.04001        0.559        0.716
##  2918     51       1    0.621 0.04110        0.545        0.707
##  3007     46       1    0.607 0.04237        0.529        0.696
##  3271     39       1    0.592 0.04405        0.511        0.684
## 
##                 Terms_of_Employment=Permanent 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    363       1    0.997 0.00275        0.992        1.000
##    66    359       1    0.994 0.00390        0.987        1.000
##    70    358       1    0.992 0.00478        0.982        1.000
##   117    354       1    0.989 0.00553        0.978        1.000
##   122    353       1    0.986 0.00618        0.974        0.998
##   123    352       1    0.983 0.00677        0.970        0.997
##   203    345       1    0.980 0.00732        0.966        0.995
##   217    343       1    0.978 0.00784        0.962        0.993
##   232    340       1    0.975 0.00833        0.959        0.991
##   255    338       1    0.972 0.00879        0.955        0.989
##   257    337       1    0.969 0.00922        0.951        0.987
##   283    333       1    0.966 0.00964        0.947        0.985
##   286    331       1    0.963 0.01005        0.944        0.983
##   321    328       1    0.960 0.01044        0.940        0.981
##   361    324       1    0.957 0.01082        0.936        0.979
##   367    322       1    0.954 0.01118        0.933        0.976
##   371    321       1    0.951 0.01154        0.929        0.974
##   372    320       1    0.948 0.01188        0.925        0.972
##   395    316       1    0.945 0.01221        0.922        0.970
##   397    315       1    0.942 0.01254        0.918        0.967
##   426    312       1    0.939 0.01286        0.914        0.965
##   466    307       1    0.936 0.01317        0.911        0.962
##   470    305       1    0.933 0.01348        0.907        0.960
##   482    304       1    0.930 0.01378        0.903        0.957
##   492    303       1    0.927 0.01408        0.900        0.955
##   493    302       1    0.924 0.01436        0.896        0.953
##   512    301       1    0.921 0.01464        0.893        0.950
##   540    299       1    0.918 0.01491        0.889        0.947
##   568    297       1    0.915 0.01517        0.885        0.945
##   613    294       1    0.912 0.01544        0.882        0.942
##   691    286       1    0.908 0.01571        0.878        0.940
##   700    285       1    0.905 0.01598        0.874        0.937
##   704    284       1    0.902 0.01623        0.871        0.934
##   714    283       1    0.899 0.01649        0.867        0.932
##   737    280       1    0.896 0.01674        0.863        0.929
##   753    279       1    0.892 0.01698        0.860        0.926
##   803    274       1    0.889 0.01723        0.856        0.924
##   839    271       1    0.886 0.01748        0.852        0.921
##   850    270       1    0.883 0.01772        0.849        0.918
##   914    267       1    0.879 0.01796        0.845        0.915
##   939    262       1    0.876 0.01820        0.841        0.912
##   944    261       1    0.873 0.01844        0.837        0.909
##   969    258       1    0.869 0.01867        0.833        0.907
##  1015    251       1    0.866 0.01892        0.829        0.904
##  1072    246       1    0.862 0.01916        0.825        0.901
##  1081    245       1    0.859 0.01941        0.821        0.898
##  1120    241       1    0.855 0.01965        0.817        0.895
##  1150    239       1    0.852 0.01989        0.813        0.891
##  1163    238       1    0.848 0.02013        0.809        0.888
##  1165    236       1    0.844 0.02036        0.805        0.885
##  1166    235       1    0.841 0.02059        0.801        0.882
##  1184    231       1    0.837 0.02082        0.797        0.879
##  1205    228       1    0.833 0.02105        0.793        0.876
##  1271    217       1    0.830 0.02130        0.789        0.872
##  1274    216       1    0.826 0.02154        0.785        0.869
##  1308    213       1    0.822 0.02179        0.780        0.866
##  1353    211       1    0.818 0.02203        0.776        0.862
##  1356    210       1    0.814 0.02227        0.772        0.859
##  1411    207       1    0.810 0.02250        0.767        0.856
##  1429    205       1    0.806 0.02274        0.763        0.852
##  1490    198       1    0.802 0.02299        0.758        0.849
##  1590    191       1    0.798 0.02325        0.754        0.845
##  1662    187       1    0.794 0.02351        0.749        0.841
##  1681    185       1    0.789 0.02377        0.744        0.837
##  1689    184       1    0.785 0.02403        0.739        0.834
##  1811    173       1    0.781 0.02431        0.734        0.830
##  1818    171       1    0.776 0.02459        0.729        0.826
##  1820    170       1    0.771 0.02487        0.724        0.822
##  1879    166       1    0.767 0.02515        0.719        0.818
##  1992    159       1    0.762 0.02545        0.714        0.814
##  2017    156       1    0.757 0.02575        0.708        0.809
##  2052    151       1    0.752 0.02606        0.703        0.805
##  2054    150       1    0.747 0.02637        0.697        0.801
##  2109    147       1    0.742 0.02667        0.692        0.796
##  2134    145       1    0.737 0.02698        0.686        0.792
##  2147    144       1    0.732 0.02727        0.680        0.787
##  2267    136       1    0.726 0.02760        0.674        0.783
##  2317    131       1    0.721 0.02794        0.668        0.778
##  2416    123       1    0.715 0.02832        0.662        0.773
##  2434    121       1    0.709 0.02869        0.655        0.768
##  2453    120       1    0.703 0.02906        0.648        0.762
##  2470    119       1    0.697 0.02941        0.642        0.757
##  2489    118       1    0.691 0.02975        0.635        0.752
##  2523    116       1    0.685 0.03008        0.629        0.747
##  2552    112       1    0.679 0.03043        0.622        0.742
##  2595    107       1    0.673 0.03080        0.615        0.736
##  2656    104       1    0.666 0.03117        0.608        0.730
##  2657    103       1    0.660 0.03154        0.601        0.725
##  2759     98       1    0.653 0.03192        0.594        0.719
##  2850     90       1    0.646 0.03238        0.586        0.713
##  2893     87       1    0.639 0.03285        0.577        0.706
##  2929     83       1    0.631 0.03335        0.569        0.700
##  3001     77       1    0.623 0.03390        0.560        0.693
##  3029     76       1    0.614 0.03443        0.551        0.686
##  3069     72       1    0.606 0.03500        0.541        0.679
##  3079     71       1    0.597 0.03553        0.532        0.671
##  3094     68       1    0.589 0.03608        0.522        0.664
##  3136     62       1    0.579 0.03672        0.511        0.656
##  3178     56       1    0.569 0.03749        0.500        0.647
##  3183     54       1    0.558 0.03825        0.488        0.638
##  3226     50       1    0.547 0.03908        0.476        0.629
##  3262     45       1    0.535 0.04006        0.462        0.619
##  3344     38       1    0.521 0.04140        0.446        0.609
##  3566     25       1    0.500 0.04468        0.420        0.596
log_rank_test3 <- survdiff(Surv(time, Employment_Status) ~ Terms_of_Employment, data = Mydata)
log_rank_test3
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Terms_of_Employment, 
##     data = Mydata)
## 
##                                 N Observed Expected (O-E)^2/E (O-E)^2/V
## Terms_of_Employment=Contract  236       65     66.5    0.0348    0.0575
## Terms_of_Employment=Permanent 364      104    102.5    0.0226    0.0575
## 
##  Chisq= 0.1  on 1 degrees of freedom, p= 0.8

Plot the model

plot (KM3,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per the Terms of employment", col=c (2, 4)) 
legend("topright",c("permanent","contract"),col=c(2,4),lty=c(1,2),ncol=2,cex=0.6)

names(Mydata)
##  [1] "Serial_No"             "Gender"                "Age_Bracket"          
##  [4] "Marital_Status"        "Terms_of_Employment"   "Job_Group"            
##  [7] "Employment_Status"     "Level_of_Education"    "Academic_Designation" 
## [10] "Employment_Start_Date" "Employment_End_Date"   "Exit_Type"            
## [13] "time"

###4.Survival distribution of Staff classified by Academic Designation

KM4<-survfit (Surv (time, Employment_Status) ~ Academic_Designation, data = Mydata)

##Summaries of the model

KM4
## Call: survfit(formula = Surv(time, Employment_Status) ~ Academic_Designation, 
##     data = Mydata)
## 
##                                           n events median 0.95LCL 0.95UCL
## Academic_Designation=Non-teaching staff 381    102     NA    3262      NA
## Academic_Designation=Teaching staff     219     67   3566    3029      NA
ggsurvplot(KM4, 
           conf.int = TRUE,         # Show confidence intervals
           pval = TRUE,             # Show p-value
           risk.table = TRUE,       # Show risk table
           ggtheme = theme_minimal())

#####Model Summary

Summary4<-summary(KM4)
Summary4
## Call: survfit(formula = Surv(time, Employment_Status) ~ Academic_Designation, 
##     data = Mydata)
## 
##                 Academic_Designation=Non-teaching staff 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    381       1    0.997 0.00262        0.992        1.000
##    66    377       1    0.995 0.00372        0.987        1.000
##   122    371       1    0.992 0.00457        0.983        1.000
##   123    370       1    0.989 0.00529        0.979        1.000
##   203    363       1    0.987 0.00593        0.975        0.998
##   212    362       1    0.984 0.00651        0.971        0.997
##   217    361       1    0.981 0.00704        0.967        0.995
##   255    355       2    0.976 0.00802        0.960        0.991
##   262    352       1    0.973 0.00846        0.956        0.990
##   286    348       1    0.970 0.00888        0.953        0.988
##   293    347       1    0.967 0.00929        0.949        0.986
##   300    346       1    0.965 0.00967        0.946        0.984
##   351    342       1    0.962 0.01005        0.942        0.982
##   367    339       1    0.959 0.01041        0.939        0.979
##   372    338       1    0.956 0.01076        0.935        0.977
##   376    336       1    0.953 0.01110        0.932        0.975
##   395    335       1    0.950 0.01142        0.928        0.973
##   397    334       1    0.947 0.01174        0.925        0.971
##   399    333       1    0.945 0.01204        0.921        0.969
##   466    329       1    0.942 0.01234        0.918        0.966
##   482    326       1    0.939 0.01264        0.914        0.964
##   492    325       1    0.936 0.01293        0.911        0.962
##   493    324       1    0.933 0.01320        0.908        0.959
##   512    323       1    0.930 0.01348        0.904        0.957
##   536    321       1    0.927 0.01374        0.901        0.955
##   568    319       1    0.924 0.01400        0.897        0.952
##   613    315       1    0.921 0.01426        0.894        0.950
##   674    311       1    0.919 0.01452        0.890        0.947
##   700    309       1    0.916 0.01478        0.887        0.945
##   704    308       1    0.913 0.01502        0.884        0.942
##   714    307       1    0.910 0.01527        0.880        0.940
##   720    306       1    0.907 0.01550        0.877        0.938
##   737    301       1    0.904 0.01574        0.873        0.935
##   753    300       1    0.901 0.01597        0.870        0.932
##   772    296       1    0.898 0.01621        0.866        0.930
##   803    293       1    0.894 0.01644        0.863        0.927
##   821    290       1    0.891 0.01667        0.859        0.925
##   895    285       1    0.888 0.01690        0.856        0.922
##   925    283       1    0.885 0.01713        0.852        0.919
##   935    280       1    0.882 0.01736        0.849        0.917
##   944    278       1    0.879 0.01758        0.845        0.914
##   969    273       1    0.876 0.01781        0.841        0.911
##   998    268       1    0.872 0.01804        0.838        0.908
##  1015    265       1    0.869 0.01827        0.834        0.906
##  1072    260       1    0.866 0.01851        0.830        0.903
##  1113    258       1    0.862 0.01874        0.826        0.900
##  1120    255       1    0.859 0.01896        0.823        0.897
##  1150    252       1    0.856 0.01919        0.819        0.894
##  1161    250       1    0.852 0.01942        0.815        0.891
##  1163    249       1    0.849 0.01964        0.811        0.888
##  1165    247       1    0.845 0.01986        0.807        0.885
##  1166    246       1    0.842 0.02007        0.803        0.882
##  1184    243       1    0.838 0.02029        0.800        0.879
##  1192    241       1    0.835 0.02050        0.796        0.876
##  1201    240       1    0.831 0.02071        0.792        0.873
##  1205    238       1    0.828 0.02091        0.788        0.870
##  1271    230       1    0.824 0.02113        0.784        0.867
##  1274    229       1    0.821 0.02134        0.780        0.864
##  1308    226       1    0.817 0.02155        0.776        0.860
##  1353    222       1    0.813 0.02177        0.772        0.857
##  1360    219       1    0.810 0.02198        0.768        0.854
##  1411    216       1    0.806 0.02220        0.764        0.851
##  1429    214       1    0.802 0.02241        0.759        0.847
##  1511    207       1    0.798 0.02264        0.755        0.844
##  1590    196       1    0.794 0.02288        0.751        0.840
##  1591    195       1    0.790 0.02313        0.746        0.837
##  1697    190       1    0.786 0.02338        0.741        0.833
##  1699    189       1    0.782 0.02362        0.737        0.830
##  1725    187       1    0.778 0.02386        0.732        0.826
##  1811    181       1    0.773 0.02411        0.728        0.822
##  1818    179       1    0.769 0.02436        0.723        0.818
##  1879    174       1    0.765 0.02462        0.718        0.814
##  1958    172       1    0.760 0.02487        0.713        0.811
##  1992    167       1    0.756 0.02514        0.708        0.807
##  2017    165       1    0.751 0.02540        0.703        0.802
##  2054    162       2    0.742 0.02592        0.693        0.794
##  2090    156       1    0.737 0.02618        0.687        0.790
##  2109    152       1    0.732 0.02646        0.682        0.786
##  2134    151       1    0.727 0.02672        0.677        0.782
##  2186    145       1    0.722 0.02701        0.671        0.777
##  2267    140       1    0.717 0.02730        0.666        0.773
##  2317    133       2    0.706 0.02793        0.654        0.763
##  2403    123       1    0.701 0.02829        0.647        0.758
##  2416    121       1    0.695 0.02864        0.641        0.753
##  2453    117       1    0.689 0.02901        0.634        0.748
##  2489    115       1    0.683 0.02937        0.628        0.743
##  2581    107       1    0.677 0.02978        0.621        0.737
##  2657    102       1    0.670 0.03022        0.613        0.732
##  2850     90       1    0.662 0.03078        0.605        0.726
##  2918     84       1    0.655 0.03141        0.596        0.719
##  3001     77       1    0.646 0.03213        0.586        0.712
##  3007     76       1    0.638 0.03282        0.576        0.705
##  3079     71       1    0.629 0.03356        0.566        0.698
##  3094     69       1    0.619 0.03429        0.556        0.690
##  3136     64       1    0.610 0.03509        0.545        0.683
##  3178     59       1    0.599 0.03599        0.533        0.674
##  3183     58       1    0.589 0.03682        0.521        0.666
##  3226     54       1    0.578 0.03772        0.509        0.657
##  3262     51       1    0.567 0.03865        0.496        0.648
## 
##                 Academic_Designation=Teaching staff 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    41    215       1    0.995 0.00464        0.986        1.000
##    70    213       1    0.991 0.00656        0.978        1.000
##    89    212       1    0.986 0.00802        0.970        1.000
##   108    210       1    0.981 0.00926        0.963        1.000
##   115    209       1    0.977 0.01034        0.957        0.997
##   117    208       1    0.972 0.01130        0.950        0.994
##   131    207       1    0.967 0.01218        0.944        0.991
##   182    206       1    0.963 0.01300        0.937        0.988
##   232    203       1    0.958 0.01377        0.931        0.985
##   238    202       1    0.953 0.01450        0.925        0.982
##   257    200       1    0.948 0.01519        0.919        0.979
##   274    199       1    0.944 0.01584        0.913        0.975
##   283    197       1    0.939 0.01647        0.907        0.972
##   304    196       1    0.934 0.01707        0.901        0.968
##   321    193       1    0.929 0.01765        0.895        0.964
##   361    190       1    0.924 0.01822        0.889        0.961
##   371    189       1    0.919 0.01877        0.883        0.957
##   426    184       1    0.914 0.01932        0.877        0.953
##   470    181       1    0.909 0.01987        0.871        0.949
##   527    179       1    0.904 0.02039        0.865        0.945
##   540    178       1    0.899 0.02090        0.859        0.941
##   575    177       1    0.894 0.02139        0.853        0.937
##   582    176       1    0.889 0.02187        0.847        0.933
##   691    166       1    0.884 0.02238        0.841        0.929
##   798    160       1    0.878 0.02291        0.834        0.924
##   839    158       1    0.873 0.02343        0.828        0.920
##   850    156       1    0.867 0.02394        0.821        0.915
##   857    155       1    0.861 0.02443        0.815        0.911
##   914    153       1    0.856 0.02491        0.808        0.906
##   939    149       1    0.850 0.02540        0.802        0.901
##  1081    143       1    0.844 0.02590        0.795        0.896
##  1198    140       1    0.838 0.02641        0.788        0.891
##  1225    135       1    0.832 0.02694        0.781        0.886
##  1264    133       1    0.826 0.02745        0.773        0.881
##  1330    129       1    0.819 0.02797        0.766        0.876
##  1356    128       1    0.813 0.02848        0.759        0.870
##  1393    125       1    0.806 0.02898        0.751        0.865
##  1444    122       1    0.800 0.02949        0.744        0.860
##  1490    119       1    0.793 0.03000        0.736        0.854
##  1662    110       1    0.786 0.03058        0.728        0.848
##  1681    107       1    0.778 0.03116        0.720        0.842
##  1689    106       1    0.771 0.03172        0.711        0.836
##  1723    105       1    0.764 0.03226        0.703        0.830
##  1820     98       1    0.756 0.03286        0.694        0.823
##  2052     92       1    0.748 0.03351        0.685        0.816
##  2080     91       1    0.739 0.03413        0.675        0.809
##  2147     89       1    0.731 0.03475        0.666        0.802
##  2267     87       1    0.723 0.03535        0.657        0.795
##  2358     82       1    0.714 0.03600        0.647        0.788
##  2434     78       1    0.705 0.03668        0.636        0.780
##  2460     77       1    0.696 0.03733        0.626        0.773
##  2462     76       1    0.686 0.03795        0.616        0.765
##  2470     75       1    0.677 0.03853        0.606        0.757
##  2523     74       1    0.668 0.03908        0.596        0.749
##  2552     72       1    0.659 0.03962        0.586        0.741
##  2595     67       1    0.649 0.04023        0.575        0.733
##  2653     66       1    0.639 0.04081        0.564        0.724
##  2656     65       1    0.629 0.04135        0.553        0.716
##  2751     61       1    0.619 0.04194        0.542        0.707
##  2759     60       1    0.609 0.04249        0.531        0.698
##  2893     54       1    0.597 0.04317        0.519        0.688
##  2929     51       1    0.586 0.04389        0.506        0.678
##  3029     45       1    0.573 0.04480        0.491        0.668
##  3069     43       1    0.559 0.04569        0.477        0.657
##  3271     32       1    0.542 0.04749        0.456        0.643
##  3344     28       1    0.523 0.04958        0.434        0.629
##  3566     17       1    0.492 0.05538        0.394        0.613
log_rank_test4 <- survdiff(Surv(time, Employment_Status) ~ Academic_Designation, data = Mydata)
log_rank_test4
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Academic_Designation, 
##     data = Mydata)
## 
##                                           N Observed Expected (O-E)^2/E
## Academic_Designation=Non-teaching staff 381      102    107.2     0.252
## Academic_Designation=Teaching staff     219       67     61.8     0.438
##                                         (O-E)^2/V
## Academic_Designation=Non-teaching staff     0.691
## Academic_Designation=Teaching staff         0.691
## 
##  Chisq= 0.7  on 1 degrees of freedom, p= 0.4

###Plotting the model

plot (KM4,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per the Academic_Designation", col=c (2, 4)) 
legend("topright",c("Teaching","Non-teaching"),col=c(2,4),lty=c(1,2),ncol=2,cex=0.6)

###5.Survival distribution of Staff classified by Level_of_Education

KM5<-survfit (Surv (time, Employment_Status) ~Level_of_Education , data = Mydata)

##Summaries of the model

KM5
## Call: survfit(formula = Surv(time, Employment_Status) ~ Level_of_Education, 
##     data = Mydata)
## 
##                                  n events median 0.95LCL 0.95UCL
## Level_of_Education=Certificate 175     44     NA    3262      NA
## Level_of_Education=Degree       41     13   3226    2581      NA
## Level_of_Education=Diploma     165     45     NA    3178      NA
## Level_of_Education=Masters      78     21     NA    2470      NA
## Level_of_Education=Ph.D        141     46   3566    3029      NA

#####Model Summary

Summary5<-summary(KM5)
Summary5
## Call: survfit(formula = Surv(time, Employment_Status) ~ Level_of_Education, 
##     data = Mydata)
## 
##                 Level_of_Education=Certificate 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##   122    170       1    0.994 0.00587        0.983        1.000
##   123    169       1    0.988 0.00827        0.972        1.000
##   212    166       1    0.982 0.01014        0.963        1.000
##   217    165       1    0.976 0.01170        0.954        1.000
##   255    161       1    0.970 0.01310        0.945        0.996
##   286    157       1    0.964 0.01440        0.936        0.993
##   293    156       1    0.958 0.01558        0.928        0.989
##   300    155       1    0.952 0.01666        0.920        0.985
##   351    153       1    0.946 0.01767        0.911        0.981
##   367    152       1    0.939 0.01862        0.903        0.976
##   376    151       1    0.933 0.01951        0.896        0.972
##   399    150       1    0.927 0.02035        0.888        0.968
##   466    148       1    0.921 0.02115        0.880        0.963
##   492    145       1    0.914 0.02194        0.872        0.958
##   493    144       1    0.908 0.02268        0.864        0.953
##   512    143       1    0.902 0.02340        0.857        0.949
##   568    141       1    0.895 0.02409        0.849        0.944
##   674    136       1    0.889 0.02479        0.841        0.939
##   704    134       1    0.882 0.02548        0.833        0.933
##   714    133       1    0.875 0.02614        0.826        0.928
##   998    119       1    0.868 0.02693        0.817        0.922
##  1072    115       1    0.860 0.02774        0.808        0.917
##  1113    114       1    0.853 0.02850        0.799        0.911
##  1120    112       1    0.845 0.02925        0.790        0.905
##  1163    109       1    0.837 0.02999        0.781        0.898
##  1205    105       1    0.830 0.03075        0.771        0.892
##  1308    100       1    0.821 0.03154        0.762        0.885
##  1429     94       1    0.812 0.03239        0.751        0.878
##  1697     85       1    0.803 0.03339        0.740        0.871
##  1699     84       1    0.793 0.03433        0.729        0.864
##  1725     83       1    0.784 0.03522        0.718        0.856
##  1811     80       1    0.774 0.03612        0.706        0.848
##  1818     79       1    0.764 0.03697        0.695        0.840
##  1958     77       1    0.754 0.03780        0.684        0.832
##  1992     75       1    0.744 0.03861        0.672        0.824
##  2267     68       1    0.733 0.03956        0.660        0.815
##  2317     64       1    0.722 0.04057        0.647        0.806
##  2416     57       1    0.709 0.04179        0.632        0.796
##  2489     55       1    0.696 0.04297        0.617        0.786
##  3001     39       1    0.678 0.04543        0.595        0.774
##  3007     38       1    0.661 0.04761        0.574        0.761
##  3094     34       1    0.641 0.05002        0.550        0.747
##  3136     30       1    0.620 0.05272        0.525        0.732
##  3262     24       1    0.594 0.05649        0.493        0.716
## 
##                 Level_of_Education=Degree 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##   262     41       1    0.976  0.0241        0.930        1.000
##   395     38       1    0.950  0.0345        0.885        1.000
##   737     36       1    0.924  0.0425        0.844        1.000
##   753     35       1    0.897  0.0488        0.806        0.998
##   935     32       1    0.869  0.0547        0.768        0.983
##   944     30       1    0.840  0.0601        0.730        0.967
##  1165     26       1    0.808  0.0659        0.689        0.948
##  1184     25       1    0.776  0.0707        0.649        0.927
##  2090     18       1    0.732  0.0788        0.593        0.904
##  2317     16       1    0.687  0.0862        0.537        0.878
##  2581     13       1    0.634  0.0944        0.473        0.849
##  3079     10       1    0.570  0.1041        0.399        0.816
##  3226      7       1    0.489  0.1168        0.306        0.781
## 
##                 Level_of_Education=Diploma 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    165       1    0.994 0.00604        0.982        1.000
##    66    164       1    0.988 0.00852        0.971        1.000
##   203    156       1    0.982 0.01056        0.961        1.000
##   255    153       1    0.975 0.01229        0.951        1.000
##   372    148       1    0.969 0.01386        0.942        0.996
##   397    147       1    0.962 0.01525        0.933        0.992
##   482    144       1    0.955 0.01654        0.923        0.988
##   536    142       1    0.949 0.01774        0.914        0.984
##   613    140       1    0.942 0.01886        0.906        0.979
##   700    138       1    0.935 0.01992        0.897        0.975
##   720    137       1    0.928 0.02091        0.888        0.970
##   772    133       1    0.921 0.02189        0.879        0.965
##   803    131       1    0.914 0.02282        0.870        0.960
##   821    129       1    0.907 0.02372        0.862        0.955
##   895    126       1    0.900 0.02460        0.853        0.949
##   925    125       1    0.893 0.02544        0.844        0.944
##   969    122       1    0.885 0.02626        0.835        0.938
##  1015    119       1    0.878 0.02707        0.826        0.933
##  1150    117       1    0.870 0.02786        0.817        0.927
##  1161    115       1    0.863 0.02863        0.808        0.921
##  1166    114       1    0.855 0.02936        0.800        0.915
##  1192    111       1    0.848 0.03009        0.791        0.909
##  1201    110       1    0.840 0.03079        0.782        0.902
##  1271    107       1    0.832 0.03148        0.773        0.896
##  1274    106       1    0.824 0.03215        0.763        0.890
##  1353    102       1    0.816 0.03283        0.754        0.883
##  1360    100       1    0.808 0.03350        0.745        0.876
##  1411     98       1    0.800 0.03416        0.735        0.869
##  1511     93       1    0.791 0.03486        0.726        0.862
##  1590     89       1    0.782 0.03558        0.715        0.855
##  1591     88       1    0.773 0.03627        0.705        0.848
##  1879     78       1    0.763 0.03714        0.694        0.840
##  2017     73       1    0.753 0.03807        0.682        0.831
##  2054     70       2    0.731 0.03991        0.657        0.814
##  2109     65       1    0.720 0.04085        0.644        0.805
##  2134     64       1    0.709 0.04173        0.632        0.796
##  2186     59       1    0.697 0.04272        0.618        0.786
##  2403     51       1    0.683 0.04401        0.602        0.775
##  2453     48       1    0.669 0.04534        0.586        0.764
##  2657     42       1    0.653 0.04697        0.567        0.752
##  2850     35       1    0.634 0.04920        0.545        0.739
##  2918     31       1    0.614 0.05169        0.521        0.724
##  3178     24       1    0.588 0.05551        0.489        0.708
##  3183     23       1    0.563 0.05869        0.459        0.690
## 
##                 Level_of_Education=Masters 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    89     76       1    0.987  0.0131        0.962        1.000
##   131     74       1    0.974  0.0185        0.938        1.000
##   232     71       1    0.960  0.0227        0.916        1.000
##   283     68       1    0.946  0.0264        0.895        0.999
##   371     67       1    0.932  0.0296        0.875        0.991
##   470     60       1    0.916  0.0329        0.854        0.983
##   691     52       1    0.898  0.0367        0.829        0.973
##   839     50       1    0.880  0.0401        0.805        0.963
##   914     49       1    0.862  0.0431        0.782        0.951
##  1081     43       1    0.842  0.0466        0.756        0.939
##  1198     42       1    0.822  0.0496        0.731        0.926
##  1225     41       1    0.802  0.0523        0.706        0.912
##  1490     37       1    0.781  0.0552        0.680        0.897
##  1689     34       1    0.758  0.0581        0.652        0.881
##  2052     31       1    0.733  0.0612        0.623        0.863
##  2358     28       1    0.707  0.0644        0.592        0.845
##  2434     26       1    0.680  0.0674        0.560        0.826
##  2460     25       1    0.653  0.0700        0.529        0.805
##  2470     24       1    0.625  0.0721        0.499        0.784
##  2751     19       1    0.593  0.0755        0.462        0.761
##  2929     15       1    0.553  0.0801        0.416        0.735
## 
##                 Level_of_Education=Ph.D 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    41    139       1    0.993 0.00717        0.979        1.000
##    70    137       1    0.986 0.01014        0.966        1.000
##   108    136       1    0.978 0.01239        0.954        1.000
##   115    135       1    0.971 0.01426        0.944        0.999
##   117    134       1    0.964 0.01589        0.933        0.995
##   182    133       1    0.957 0.01734        0.923        0.991
##   238    132       1    0.949 0.01866        0.913        0.987
##   257    131       1    0.942 0.01988        0.904        0.982
##   274    130       1    0.935 0.02100        0.895        0.977
##   304    129       1    0.928 0.02206        0.885        0.972
##   321    126       1    0.920 0.02308        0.876        0.967
##   361    123       1    0.913 0.02407        0.867        0.961
##   426    122       1    0.905 0.02501        0.858        0.956
##   527    120       1    0.898 0.02591        0.848        0.950
##   540    119       1    0.890 0.02677        0.839        0.944
##   575    118       1    0.883 0.02759        0.830        0.938
##   582    117       1    0.875 0.02836        0.821        0.932
##   798    110       1    0.867 0.02920        0.812        0.926
##   850    107       1    0.859 0.03003        0.802        0.920
##   857    106       1    0.851 0.03082        0.793        0.914
##   939    103       1    0.843 0.03161        0.783        0.907
##  1264     93       1    0.834 0.03254        0.772        0.900
##  1330     91       1    0.824 0.03345        0.761        0.893
##  1356     90       1    0.815 0.03431        0.751        0.885
##  1393     88       1    0.806 0.03515        0.740        0.878
##  1444     85       1    0.797 0.03599        0.729        0.870
##  1662     76       1    0.786 0.03701        0.717        0.862
##  1681     73       1    0.775 0.03804        0.704        0.854
##  1723     72       1    0.765 0.03901        0.692        0.845
##  1820     65       1    0.753 0.04014        0.678        0.836
##  2080     61       1    0.740 0.04133        0.664        0.826
##  2147     59       1    0.728 0.04250        0.649        0.816
##  2267     57       1    0.715 0.04363        0.635        0.806
##  2462     52       1    0.701 0.04490        0.619        0.795
##  2523     51       1    0.688 0.04608        0.603        0.784
##  2552     49       1    0.674 0.04723        0.587        0.773
##  2595     46       1    0.659 0.04842        0.571        0.761
##  2653     45       1    0.644 0.04951        0.554        0.749
##  2656     44       1    0.630 0.05050        0.538        0.737
##  2759     42       1    0.615 0.05148        0.522        0.724
##  2893     39       1    0.599 0.05251        0.504        0.711
##  3029     33       1    0.581 0.05397        0.484        0.697
##  3069     31       1    0.562 0.05538        0.463        0.682
##  3271     23       1    0.538 0.05811        0.435        0.664
##  3344     20       1    0.511 0.06111        0.404        0.646
##  3566     12       1    0.468 0.06927        0.350        0.626
log_rank_test5 <- survdiff(Surv(time, Employment_Status) ~ Level_of_Education, data = Mydata)
log_rank_test5
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Level_of_Education, 
##     data = Mydata)
## 
##                                  N Observed Expected (O-E)^2/E (O-E)^2/V
## Level_of_Education=Certificate 175       44     48.7    0.4445    0.6245
## Level_of_Education=Degree       41       13     12.2    0.0582    0.0628
## Level_of_Education=Diploma     165       45     46.4    0.0418    0.0577
## Level_of_Education=Masters      78       21     19.8    0.0686    0.0778
## Level_of_Education=Ph.D        141       46     42.0    0.3879    0.5166
## 
##  Chisq= 1  on 4 degrees of freedom, p= 0.9

###Plotting the model

plot (KM5,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per theLevel of Education", col=c (2, 4,6,8,10)) 
legend("topright",c("Certificate","Diploma","Degree","Masters","Ph.D"),col=c(2,4,6,8,10),lty=c(1,2),ncol=5,cex=0.6)

###6.Survival distribution of Staff classified by Marital Status

KM6<-survfit (Surv (time, Employment_Status) ~ Marital_Status, data = Mydata)

##Summaries of the model

KM6
## Call: survfit(formula = Surv(time, Employment_Status) ~ Marital_Status, 
##     data = Mydata)
## 
##                                     n events median 0.95LCL 0.95UCL
## Marital_Status=Divorced/Separated  33      7     NA    3079      NA
## Marital_Status=Married            472    139     NA    3183      NA
## Marital_Status=Single              95     23     NA      NA      NA

#####Model Summary

Summary6<-summary(KM6)
Summary6
## Call: survfit(formula = Surv(time, Employment_Status) ~ Marital_Status, 
##     data = Mydata)
## 
##                 Marital_Status=Divorced/Separated 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##   714     29       1    0.966  0.0339        0.901        1.000
##  1811     23       1    0.924  0.0523        0.827        1.000
##  2147     20       1    0.877  0.0670        0.755        1.000
##  2434     17       1    0.826  0.0806        0.682        1.000
##  2523     16       1    0.774  0.0906        0.616        0.974
##  2656     14       1    0.719  0.0995        0.548        0.943
##  3079     10       1    0.647  0.1126        0.460        0.910
## 
##                 Marital_Status=Married 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    31    470       1    0.998 0.00213        0.994        1.000
##    41    469       1    0.996 0.00300        0.990        1.000
##    70    465       1    0.994 0.00368        0.986        1.000
##    89    463       1    0.991 0.00425        0.983        1.000
##   108    461       1    0.989 0.00476        0.980        0.999
##   115    458       1    0.987 0.00521        0.977        0.997
##   117    457       1    0.985 0.00563        0.974        0.996
##   122    455       1    0.983 0.00602        0.971        0.995
##   123    454       1    0.981 0.00639        0.968        0.993
##   131    452       1    0.978 0.00673        0.965        0.992
##   182    447       1    0.976 0.00706        0.963        0.990
##   203    446       1    0.974 0.00738        0.960        0.989
##   212    443       1    0.972 0.00768        0.957        0.987
##   217    442       1    0.970 0.00797        0.954        0.985
##   232    438       1    0.967 0.00826        0.951        0.984
##   238    437       1    0.965 0.00853        0.949        0.982
##   255    434       2    0.961 0.00905        0.943        0.979
##   257    432       1    0.959 0.00930        0.941        0.977
##   262    430       1    0.956 0.00954        0.938        0.975
##   274    429       1    0.954 0.00978        0.935        0.974
##   283    426       1    0.952 0.01001        0.933        0.972
##   286    424       1    0.950 0.01023        0.930        0.970
##   293    423       1    0.947 0.01045        0.927        0.968
##   300    422       1    0.945 0.01066        0.925        0.966
##   321    417       1    0.943 0.01088        0.922        0.964
##   351    413       1    0.941 0.01109        0.919        0.963
##   361    411       1    0.938 0.01129        0.916        0.961
##   367    409       1    0.936 0.01150        0.914        0.959
##   371    408       1    0.934 0.01170        0.911        0.957
##   372    407       1    0.931 0.01189        0.908        0.955
##   395    404       1    0.929 0.01208        0.906        0.953
##   399    403       1    0.927 0.01227        0.903        0.951
##   426    399       1    0.925 0.01246        0.900        0.949
##   466    395       1    0.922 0.01264        0.898        0.947
##   470    392       1    0.920 0.01283        0.895        0.945
##   482    391       1    0.917 0.01301        0.892        0.943
##   492    389       1    0.915 0.01319        0.890        0.941
##   493    388       1    0.913 0.01336        0.887        0.939
##   527    387       1    0.910 0.01354        0.884        0.937
##   536    386       1    0.908 0.01370        0.882        0.935
##   540    385       1    0.906 0.01387        0.879        0.933
##   568    383       1    0.903 0.01403        0.876        0.931
##   582    379       1    0.901 0.01420        0.874        0.929
##   613    378       1    0.899 0.01436        0.871        0.927
##   674    372       1    0.896 0.01452        0.868        0.925
##   691    367       1    0.894 0.01469        0.865        0.923
##   700    365       1    0.891 0.01485        0.863        0.921
##   720    362       1    0.889 0.01501        0.860        0.919
##   737    357       1    0.886 0.01517        0.857        0.917
##   753    356       1    0.884 0.01533        0.854        0.914
##   772    353       1    0.881 0.01549        0.851        0.912
##   798    349       1    0.879 0.01565        0.849        0.910
##   803    348       1    0.876 0.01581        0.846        0.908
##   821    345       1    0.874 0.01597        0.843        0.906
##   839    344       1    0.871 0.01612        0.840        0.903
##   850    343       1    0.869 0.01627        0.837        0.901
##   857    341       1    0.866 0.01642        0.834        0.899
##   914    336       1    0.864 0.01658        0.832        0.897
##   925    333       1    0.861 0.01673        0.829        0.894
##   939    328       1    0.858 0.01688        0.826        0.892
##   944    327       1    0.856 0.01703        0.823        0.890
##   998    322       1    0.853 0.01719        0.820        0.887
##  1015    317       1    0.850 0.01734        0.817        0.885
##  1072    309       1    0.848 0.01750        0.814        0.883
##  1081    308       1    0.845 0.01766        0.811        0.880
##  1113    305       1    0.842 0.01782        0.808        0.878
##  1150    300       1    0.839 0.01798        0.805        0.875
##  1165    297       1    0.836 0.01814        0.802        0.873
##  1166    296       1    0.834 0.01830        0.798        0.870
##  1184    293       1    0.831 0.01845        0.795        0.868
##  1192    291       1    0.828 0.01861        0.792        0.865
##  1198    290       1    0.825 0.01876        0.789        0.863
##  1201    289       1    0.822 0.01891        0.786        0.860
##  1205    287       1    0.819 0.01906        0.783        0.858
##  1225    279       1    0.816 0.01922        0.780        0.855
##  1264    274       1    0.813 0.01938        0.776        0.852
##  1271    272       1    0.810 0.01954        0.773        0.850
##  1274    271       1    0.807 0.01969        0.770        0.847
##  1308    267       1    0.804 0.01985        0.766        0.844
##  1330    266       1    0.801 0.02001        0.763        0.842
##  1353    262       1    0.798 0.02016        0.760        0.839
##  1411    258       1    0.795 0.02032        0.756        0.836
##  1429    255       1    0.792 0.02048        0.753        0.833
##  1444    252       1    0.789 0.02064        0.750        0.830
##  1490    247       1    0.786 0.02080        0.746        0.828
##  1511    244       1    0.783 0.02096        0.743        0.825
##  1590    235       1    0.779 0.02113        0.739        0.822
##  1662    225       1    0.776 0.02132        0.735        0.819
##  1681    223       1    0.772 0.02151        0.731        0.816
##  1689    222       1    0.769 0.02169        0.727        0.812
##  1697    221       1    0.765 0.02187        0.724        0.809
##  1699    220       1    0.762 0.02205        0.720        0.806
##  1723    218       1    0.758 0.02222        0.716        0.803
##  1725    217       1    0.755 0.02239        0.712        0.800
##  1818    207       1    0.751 0.02258        0.708        0.797
##  1820    206       1    0.748 0.02276        0.704        0.794
##  1879    202       1    0.744 0.02295        0.700        0.790
##  1958    200       1    0.740 0.02313        0.696        0.787
##  1992    195       1    0.736 0.02332        0.692        0.783
##  2017    192       1    0.732 0.02351        0.688        0.780
##  2054    187       2    0.725 0.02391        0.679        0.773
##  2080    183       1    0.721 0.02410        0.675        0.770
##  2090    181       1    0.717 0.02429        0.671        0.766
##  2134    176       1    0.713 0.02450        0.666        0.762
##  2186    171       1    0.708 0.02470        0.662        0.759
##  2267    168       2    0.700 0.02512        0.653        0.751
##  2317    160       2    0.691 0.02556        0.643        0.743
##  2358    155       1    0.687 0.02578        0.638        0.739
##  2403    147       1    0.682 0.02602        0.633        0.735
##  2416    145       1    0.677 0.02626        0.628        0.731
##  2453    142       1    0.673 0.02651        0.623        0.727
##  2460    141       1    0.668 0.02675        0.617        0.722
##  2462    140       1    0.663 0.02698        0.612        0.718
##  2470    138       1    0.658 0.02721        0.607        0.714
##  2489    137       1    0.654 0.02743        0.602        0.710
##  2552    133       1    0.649 0.02766        0.597        0.705
##  2581    126       1    0.643 0.02792        0.591        0.701
##  2595    124       1    0.638 0.02817        0.585        0.696
##  2751    117       1    0.633 0.02845        0.579        0.691
##  2759    116       1    0.627 0.02872        0.574        0.686
##  2893    103       1    0.621 0.02908        0.567        0.681
##  2918     99       1    0.615 0.02946        0.560        0.676
##  2929     97       1    0.609 0.02983        0.553        0.670
##  3007     89       1    0.602 0.03027        0.545        0.664
##  3029     88       1    0.595 0.03069        0.538        0.658
##  3069     82       1    0.588 0.03116        0.530        0.652
##  3094     80       1    0.580 0.03162        0.522        0.646
##  3136     75       1    0.573 0.03214        0.513        0.639
##  3178     71       1    0.565 0.03268        0.504        0.632
##  3183     69       1    0.556 0.03321        0.495        0.625
##  3226     64       1    0.548 0.03381        0.485        0.618
##  3262     59       1    0.538 0.03449        0.475        0.610
##  3271     57       1    0.529 0.03516        0.464        0.603
##  3344     51       1    0.519 0.03596        0.453        0.594
##  3566     34       1    0.503 0.03800        0.434        0.584
## 
##                 Marital_Status=Single 
##  time n.risk n.event survival std.err lower 95% CI upper 95% CI
##    66     93       1    0.989  0.0107        0.969        1.000
##   304     89       1    0.978  0.0153        0.949        1.000
##   376     88       1    0.967  0.0187        0.931        1.000
##   397     87       1    0.956  0.0216        0.915        0.999
##   512     85       1    0.945  0.0241        0.899        0.993
##   575     83       1    0.933  0.0263        0.883        0.986
##   704     80       1    0.922  0.0285        0.867        0.979
##   895     76       1    0.909  0.0306        0.852        0.971
##   935     74       1    0.897  0.0325        0.836        0.963
##   969     73       1    0.885  0.0343        0.820        0.955
##  1120     69       1    0.872  0.0361        0.804        0.946
##  1161     68       1    0.859  0.0378        0.788        0.937
##  1163     67       1    0.846  0.0394        0.773        0.927
##  1356     64       1    0.833  0.0409        0.757        0.917
##  1360     62       1    0.820  0.0424        0.741        0.907
##  1393     59       1    0.806  0.0439        0.724        0.897
##  1591     54       1    0.791  0.0456        0.707        0.885
##  2052     47       1    0.774  0.0476        0.686        0.873
##  2109     45       1    0.757  0.0495        0.666        0.861
##  2653     32       1    0.733  0.0533        0.636        0.846
##  2657     31       1    0.710  0.0566        0.607        0.830
##  2850     27       1    0.683  0.0603        0.575        0.812
##  3001     24       1    0.655  0.0642        0.540        0.794
log_rank_test6 <- survdiff(Surv(time, Employment_Status) ~ Marital_Status, data = Mydata)
log_rank_test6
## Call:
## survdiff(formula = Surv(time, Employment_Status) ~ Marital_Status, 
##     data = Mydata)
## 
##                                     N Observed Expected (O-E)^2/E (O-E)^2/V
## Marital_Status=Divorced/Separated  33        7     11.5     1.770      1.90
## Marital_Status=Married            472      139    127.9     0.965      3.98
## Marital_Status=Single              95       23     29.6     1.471      1.79
## 
##  Chisq= 4.2  on 2 degrees of freedom, p= 0.1

###Plotting the model

plot (KM6,ylab = "Survival Probability", xlab = "Time 
(Days)", main= "survival probabilities as per the Marital Status", col=c (2, 4, 6)) 
legend("topright",c("Single","Married","Separated"),col=c(2,4,6),lty=c(1,2),ncol=3,cex=0.6)

cox.model1<-coxph(Surv(time,Employment_Status)~Gender,  data = Mydata)
cox.model1
## Call:
## coxph(formula = Surv(time, Employment_Status) ~ Gender, data = Mydata)
## 
##              coef exp(coef) se(coef)     z     p
## GenderMale 0.1144    1.1212   0.1597 0.716 0.474
## 
## Likelihood ratio test=0.52  on 1 df, p=0.4716
## n= 600, number of events= 169

SEMI-PARAMETRIC TESTS

COX PROPORTIONAL MODEL

cox.model<-coxph(Surv(time,Employment_Status)~Gender+Level_of_Education+Age_Bracket+Terms_of_Employment+Job_Group, data = Mydata)

###Summary of the model

summary(cox.model)
## Call:
## coxph(formula = Surv(time, Employment_Status) ~ Gender + Level_of_Education + 
##     Age_Bracket + Terms_of_Employment + Job_Group, data = Mydata)
## 
##   n= 600, number of events= 169 
## 
##                                  coef exp(coef) se(coef)      z Pr(>|z|)  
## GenderMale                    0.10388   1.10947  0.16185  0.642    0.521  
## Level_of_EducationDegree     -0.28165   0.75453  0.51675 -0.545    0.586  
## Level_of_EducationDiploma    -0.21772   0.80435  0.34576 -0.630    0.529  
## Level_of_EducationMasters    -0.48349   0.61663  0.67041 -0.721    0.471  
## Level_of_EducationPh.D       -0.43495   0.64730  0.60973 -0.713    0.476  
## Age_Bracket26-35             -0.18727   0.82922  0.29579 -0.633    0.527  
## Age_Bracket36-50             -0.46556   0.62779  0.27541 -1.690    0.091 .
## Age_Bracket51-75             -0.24779   0.78052  0.29203 -0.849    0.396  
## Terms_of_EmploymentPermanent  0.06051   1.06238  0.15991  0.378    0.705  
## Job_Group                     0.06596   1.06819  0.06105  1.080    0.280  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
##                              exp(coef) exp(-coef) lower .95 upper .95
## GenderMale                      1.1095     0.9013    0.8079     1.524
## Level_of_EducationDegree        0.7545     1.3253    0.2740     2.077
## Level_of_EducationDiploma       0.8043     1.2432    0.4084     1.584
## Level_of_EducationMasters       0.6166     1.6217    0.1657     2.294
## Level_of_EducationPh.D          0.6473     1.5449    0.1959     2.138
## Age_Bracket26-35                0.8292     1.2060    0.4644     1.481
## Age_Bracket36-50                0.6278     1.5929    0.3659     1.077
## Age_Bracket51-75                0.7805     1.2812    0.4404     1.383
## Terms_of_EmploymentPermanent    1.0624     0.9413    0.7765     1.453
## Job_Group                       1.0682     0.9362    0.9477     1.204
## 
## Concordance= 0.558  (se = 0.025 )
## Likelihood ratio test= 7.24  on 10 df,   p=0.7
## Wald test            = 7.32  on 10 df,   p=0.7
## Score (logrank) test = 7.37  on 10 df,   p=0.7
cox.zph(cox.model)
##                     chisq df    p
## Gender              0.624  1 0.43
## Level_of_Education  1.273  4 0.87
## Age_Bracket         0.346  3 0.95
## Terms_of_Employment 2.117  1 0.15
## Job_Group           0.101  1 0.75
## GLOBAL              5.046 10 0.89
cox.model<-cox.model<-coxph(Surv(time,Employment_Status)~Gender+Level_of_Education+Age_Bracket+Terms_of_Employment+Job_Group+Exit_Type, data = Mydata)
#cox.model2<-cox.model2<-coxph(Surv(time,Employment_Status)~Gender+Level_of_Education+Age_Bracket+Terms_of_Employment, data = Mydata)
#cox.model3<-cox.model3<-coxph(Surv(time,Employment_Status)~Gender+Level_of_Education+Age_Bracket+Job_Group, data = Mydata)
cox.model4<-cox.model4<-coxph(Surv(time,Employment_Status)~Gender+Level_of_Education+Terms_of_Employment+Job_Group, data = Mydata)
#cox.model5<-cox.model5<-coxph(Surv(time,Employment_Status)~Gender+Age_Bracket+Terms_of_Employment+Job_Group, data = Mydata)
#cox.model6<-cox.model6<-coxph(Surv(time,Employment_Status)~Level_of_Education+Age_Bracket+Terms_of_Employment+Job_Group, data = Mydata)
summary(cox.model)
## Call:
## coxph(formula = Surv(time, Employment_Status) ~ Gender + Level_of_Education + 
##     Age_Bracket + Terms_of_Employment + Job_Group + Exit_Type, 
##     data = Mydata)
## 
##   n= 169, number of events= 169 
##    (431 observations deleted due to missingness)
## 
##                                  coef exp(coef) se(coef)      z Pr(>|z|)  
## GenderMale                    0.04471   1.04572  0.18173  0.246   0.8057  
## Level_of_EducationDegree     -0.77191   0.46213  0.56572 -1.364   0.1724  
## Level_of_EducationDiploma    -0.48020   0.61866  0.38701 -1.241   0.2147  
## Level_of_EducationMasters    -0.78743   0.45501  0.71740 -1.098   0.2724  
## Level_of_EducationPh.D       -1.13154   0.32254  0.64509 -1.754   0.0794 .
## Age_Bracket26-35              0.17716   1.19382  0.31362  0.565   0.5721  
## Age_Bracket36-50              0.12434   1.13240  0.29299  0.424   0.6713  
## Age_Bracket51-75              0.10832   1.11441  0.31444  0.344   0.7305  
## Terms_of_EmploymentPermanent -0.28938   0.74872  0.17179 -1.685   0.0921 .
## Job_Group                     0.09134   1.09564  0.06488  1.408   0.1592  
## Exit_TypeDismissal           -0.28005   0.75575  0.37775 -0.741   0.4585  
## Exit_TypeResignation          0.11838   1.12568  0.34637  0.342   0.7325  
## Exit_TypeRetirement           0.17352   1.18949  0.53140  0.327   0.7440  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
##                              exp(coef) exp(-coef) lower .95 upper .95
## GenderMale                      1.0457     0.9563   0.73237     1.493
## Level_of_EducationDegree        0.4621     2.1639   0.15248     1.401
## Level_of_EducationDiploma       0.6187     1.6164   0.28975     1.321
## Level_of_EducationMasters       0.4550     2.1977   0.11153     1.856
## Level_of_EducationPh.D          0.3225     3.1004   0.09109     1.142
## Age_Bracket26-35                1.1938     0.8376   0.64564     2.207
## Age_Bracket36-50                1.1324     0.8831   0.63769     2.011
## Age_Bracket51-75                1.1144     0.8973   0.60172     2.064
## Terms_of_EmploymentPermanent    0.7487     1.3356   0.53468     1.048
## Job_Group                       1.0956     0.9127   0.96481     1.244
## Exit_TypeDismissal              0.7557     1.3232   0.36044     1.585
## Exit_TypeResignation            1.1257     0.8884   0.57093     2.219
## Exit_TypeRetirement             1.1895     0.8407   0.41979     3.370
## 
## Concordance= 0.557  (se = 0.026 )
## Likelihood ratio test= 12.27  on 13 df,   p=0.5
## Wald test            = 11.99  on 13 df,   p=0.5
## Score (logrank) test = 12.09  on 13 df,   p=0.5
library(MASS)
## 
## Attaching package: 'MASS'
## The following object is masked from 'package:dplyr':
## 
##     select
stepwise_model <- stepAIC(cox.model, direction = "both")
## Start:  AIC=1416.61
## Surv(time, Employment_Status) ~ Gender + Level_of_Education + 
##     Age_Bracket + Terms_of_Employment + Job_Group + Exit_Type
## 
##                       Df    AIC
## - Age_Bracket          3 1410.9
## - Level_of_Education   4 1413.5
## - Gender               1 1414.7
## - Job_Group            1 1416.6
## <none>                   1416.6
## - Terms_of_Employment  1 1417.4
## - Exit_Type            3 1967.6
## 
## Step:  AIC=1410.94
## Surv(time, Employment_Status) ~ Gender + Level_of_Education + 
##     Terms_of_Employment + Job_Group + Exit_Type
## 
##                       Df    AIC
## - Level_of_Education   4 1407.6
## - Gender               1 1409.0
## - Job_Group            1 1410.7
## <none>                   1410.9
## - Terms_of_Employment  1 1411.6
## + Age_Bracket          3 1416.6
## - Exit_Type            3 1965.5
## 
## Step:  AIC=1407.56
## Surv(time, Employment_Status) ~ Gender + Terms_of_Employment + 
##     Job_Group + Exit_Type
## 
##                       Df    AIC
## - Gender               1 1405.6
## - Job_Group            1 1405.6
## <none>                   1407.6
## - Terms_of_Employment  1 1409.2
## + Level_of_Education   4 1410.9
## + Age_Bracket          3 1413.5
## - Exit_Type            3 1958.5
## 
## Step:  AIC=1405.56
## Surv(time, Employment_Status) ~ Terms_of_Employment + Job_Group + 
##     Exit_Type
## 
##                       Df    AIC
## - Job_Group            1 1403.6
## <none>                   1405.6
## - Terms_of_Employment  1 1407.2
## + Gender               1 1407.6
## + Level_of_Education   4 1409.0
## + Age_Bracket          3 1411.5
## - Exit_Type            3 1957.0
## 
## Step:  AIC=1403.63
## Surv(time, Employment_Status) ~ Terms_of_Employment + Exit_Type
## 
##                       Df    AIC
## <none>                   1403.6
## - Terms_of_Employment  1 1405.3
## + Job_Group            1 1405.6
## + Gender               1 1405.6
## + Level_of_Education   4 1408.7
## + Age_Bracket          3 1409.6
## - Exit_Type            3 1956.8
summary(stepwise_model)
## Call:
## coxph(formula = Surv(time, Employment_Status) ~ Terms_of_Employment + 
##     Exit_Type, data = Mydata)
## 
##   n= 169, number of events= 169 
##    (431 observations deleted due to missingness)
## 
##                                  coef exp(coef) se(coef)      z Pr(>|z|)  
## Terms_of_EmploymentPermanent -0.31802   0.72759  0.16402 -1.939   0.0525 .
## Exit_TypeDismissal           -0.26707   0.76562  0.34662 -0.771   0.4410  
## Exit_TypeResignation          0.09533   1.10002  0.32313  0.295   0.7680  
## Exit_TypeRetirement           0.12718   1.13562  0.47103  0.270   0.7872  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
##                              exp(coef) exp(-coef) lower .95 upper .95
## Terms_of_EmploymentPermanent    0.7276     1.3744    0.5276     1.003
## Exit_TypeDismissal              0.7656     1.3061    0.3881     1.510
## Exit_TypeResignation            1.1000     0.9091    0.5839     2.072
## Exit_TypeRetirement             1.1356     0.8806    0.4511     2.859
## 
## Concordance= 0.548  (se = 0.025 )
## Likelihood ratio test= 7.25  on 4 df,   p=0.1
## Wald test            = 7.14  on 4 df,   p=0.1
## Score (logrank) test = 7.19  on 4 df,   p=0.1
weibfull.aft<-survreg (Surv (time, Employment_Status) ~ Gender+Level_of_Education+Age_Bracket+Terms_of_Employment+Job_Group+Exit_Type, data = Mydata, dist='weibull', control=survreg.control (maxiter=70))
summary (weibfull.aft)
## 
## Call:
## survreg(formula = Surv(time, Employment_Status) ~ Gender + Level_of_Education + 
##     Age_Bracket + Terms_of_Employment + Job_Group + Exit_Type, 
##     data = Mydata, dist = "weibull", control = survreg.control(maxiter = 70))
##                                Value Std. Error     z                    p
## (Intercept)                   7.3471     0.3616 20.32 < 0.0000000000000002
## GenderMale                   -0.0685     0.1286 -0.53                 0.59
## Level_of_EducationDegree      0.3988     0.4056  0.98                 0.33
## Level_of_EducationDiploma     0.2470     0.2753  0.90                 0.37
## Level_of_EducationMasters     0.4188     0.5165  0.81                 0.42
## Level_of_EducationPh.D        0.5322     0.4571  1.16                 0.24
## Age_Bracket26-35             -0.1298     0.2265 -0.57                 0.57
## Age_Bracket36-50             -0.0701     0.2117 -0.33                 0.74
## Age_Bracket51-75             -0.0710     0.2281 -0.31                 0.76
## Terms_of_EmploymentPermanent  0.1426     0.1225  1.16                 0.24
## Job_Group                    -0.0434     0.0465 -0.93                 0.35
## Exit_TypeDismissal            0.2168     0.2692  0.81                 0.42
## Exit_TypeResignation          0.0209     0.2469  0.08                 0.93
## Exit_TypeRetirement           0.0305     0.3831  0.08                 0.94
## Log(scale)                   -0.3160     0.0636 -4.97           0.00000067
## 
## Scale= 0.729 
## 
## Weibull distribution
## Loglik(model)= -1376.4   Loglik(intercept only)= -1379.5
##  Chisq= 6.19 on 13 degrees of freedom, p= 0.94 
## Number of Newton-Raphson Iterations: 7 
## n=169 (431 observations deleted due to missingness)