Ngày 2: So sánh 2 nhóm - Biến liên tục

Việc 1. Phân tích mô tả

1.1 Đọc dữ liệu vào R

ob = read.csv("C:\\Thach\\VN trips\\2025_7Oct\\Truong DH Kien Truc Da Nang\\Datasets\\Obesity data.csv")

1.2 Mô tả

library(table1)
## 
## Attaching package: 'table1'
## The following objects are masked from 'package:base':
## 
##     units, units<-
table1(~ age + gender + weight + height + pcfat + hypertension + diabetes, data = ob)
Overall
(N=1217)
age
Mean (SD) 47.2 (17.3)
Median [Min, Max] 48.0 [13.0, 88.0]
gender
F 862 (70.8%)
M 355 (29.2%)
weight
Mean (SD) 55.1 (9.40)
Median [Min, Max] 54.0 [34.0, 95.0]
height
Mean (SD) 157 (7.98)
Median [Min, Max] 155 [136, 185]
pcfat
Mean (SD) 31.6 (7.18)
Median [Min, Max] 32.4 [9.20, 48.4]
hypertension
Mean (SD) 0.507 (0.500)
Median [Min, Max] 1.00 [0, 1.00]
diabetes
Mean (SD) 0.111 (0.314)
Median [Min, Max] 0 [0, 1.00]

1.3 Nhận xét kết quả Cao HA và tiểu đường (so với giới tính và các đặc điểm khác)

ob$hyper = as.factor(ob$hypertension)
ob$diab = as.factor(ob$diabetes)

table1(~ age + gender + weight + height + pcfat + hypertension + hyper + diabetes + diab, data = ob)
Overall
(N=1217)
age
Mean (SD) 47.2 (17.3)
Median [Min, Max] 48.0 [13.0, 88.0]
gender
F 862 (70.8%)
M 355 (29.2%)
weight
Mean (SD) 55.1 (9.40)
Median [Min, Max] 54.0 [34.0, 95.0]
height
Mean (SD) 157 (7.98)
Median [Min, Max] 155 [136, 185]
pcfat
Mean (SD) 31.6 (7.18)
Median [Min, Max] 32.4 [9.20, 48.4]
hypertension
Mean (SD) 0.507 (0.500)
Median [Min, Max] 1.00 [0, 1.00]
hyper
0 600 (49.3%)
1 617 (50.7%)
diabetes
Mean (SD) 0.111 (0.314)
Median [Min, Max] 0 [0, 1.00]
diab
0 1082 (88.9%)
1 135 (11.1%)

1.4 Trình bày median (Q1, Q3)

table1(~ age + weight + height + pcfat, data = ob, render.continuous = c(. = "Mean (SD)", . = "Median [Q1, Q3]"))
Overall
(N=1217)
age
Mean (SD) 47.2 (17.3)
Median [Q1, Q3] 48.0 [35.0, 58.0]
weight
Mean (SD) 55.1 (9.40)
Median [Q1, Q3] 54.0 [49.0, 61.0]
height
Mean (SD) 157 (7.98)
Median [Q1, Q3] 155 [151, 162]
pcfat
Mean (SD) 31.6 (7.18)
Median [Q1, Q3] 32.4 [27.0, 36.8]

1.5 Mô tả theo giới tính

table1(~ age + weight + height + pcfat + hyper + diab | gender, data = ob)
F
(N=862)
M
(N=355)
Overall
(N=1217)
age
Mean (SD) 48.6 (16.4) 43.7 (18.8) 47.2 (17.3)
Median [Min, Max] 49.0 [14.0, 85.0] 44.0 [13.0, 88.0] 48.0 [13.0, 88.0]
weight
Mean (SD) 52.3 (7.72) 62.0 (9.59) 55.1 (9.40)
Median [Min, Max] 51.0 [34.0, 95.0] 62.0 [38.0, 95.0] 54.0 [34.0, 95.0]
height
Mean (SD) 153 (5.55) 165 (6.73) 157 (7.98)
Median [Min, Max] 153 [136, 170] 165 [146, 185] 155 [136, 185]
pcfat
Mean (SD) 34.7 (5.19) 24.2 (5.76) 31.6 (7.18)
Median [Min, Max] 34.7 [14.6, 48.4] 24.6 [9.20, 39.0] 32.4 [9.20, 48.4]
hyper
0 430 (49.9%) 170 (47.9%) 600 (49.3%)
1 432 (50.1%) 185 (52.1%) 617 (50.7%)
diab
0 760 (88.2%) 322 (90.7%) 1082 (88.9%)
1 102 (11.8%) 33 (9.3%) 135 (11.1%)

1.6 Đánh giá khác biệt giữa 2 nhóm

library(compareGroups)
createTable(compareGroups(gender ~ age + weight + height + pcfat + hyper + diab, data = ob))
## 
## --------Summary descriptives table by 'gender'---------
## 
## ________________________________________ 
##             F           M      p.overall 
##           N=862       N=355              
## ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ 
## age    48.6 (16.4) 43.7 (18.8)  <0.001   
## weight 52.3 (7.72) 62.0 (9.59)  <0.001   
## height 153 (5.55)  165 (6.73)   <0.001   
## pcfat  34.7 (5.19) 24.2 (5.76)  <0.001   
## hyper:                           0.569   
##     0  430 (49.9%) 170 (47.9%)           
##     1  432 (50.1%) 185 (52.1%)           
## diab:                            0.238   
##     0  760 (88.2%) 322 (90.7%)           
##     1  102 (11.8%) 33 (9.30%)            
## ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

Việc 2. Phân tích khác biệt giữa 2 nhóm

2.1 Dữ liệu tải trọng

A = c(14, 4, 10, 6, 3, 11, 12)
B = c(16, 17, 13, 12, 7, 16, 11, 8, 7)

wt = c(A, B)
group = c(rep("A", 7), rep("B", 9))
df = data.frame(wt, group)
dim(df)
## [1] 16  2

2.2 Đánh giá phân bố

Dùng biểu đồ

library(lessR)
## Warning: package 'lessR' was built under R version 4.3.3
## 
## lessR 4.3.9                         feedback: gerbing@pdx.edu 
## --------------------------------------------------------------
## > d <- Read("")   Read text, Excel, SPSS, SAS, or R data file
##   d is default data frame, data= in analysis routines optional
## 
## Many examples of reading, writing, and manipulating data, 
## graphics, testing means and proportions, regression, factor analysis,
## customization, and descriptive statistics from pivot tables
##   Enter: browseVignettes("lessR")
## 
## View lessR updates, now including time series forecasting
##   Enter: news(package="lessR")
## 
## Interactive data analysis
##   Enter: interact()
## 
## Attaching package: 'lessR'
## The following object is masked from 'package:table1':
## 
##     label
Histogram(wt, data = df)
## >>> Note: wt is not in a data frame (table)
## >>> Note: wt is not in a data frame (table)

## >>> Suggestions 
## bin_width: set the width of each bin 
## bin_start: set the start of the first bin 
## bin_end: set the end of the last bin 
## Histogram(wt, density=TRUE)  # smoothed curve + histogram 
## Plot(wt)  # Violin/Box/Scatterplot (VBS) plot 
## 
## --- wt --- 
##  
##      n   miss     mean       sd      min      mdn      max 
##      16      0    10.44     4.29     3.00    11.00    17.00 
## 
## No (Box plot) outliers 
## 
## 
## Bin Width: 2 
## Number of Bins: 8 
##  
##      Bin  Midpnt  Count    Prop  Cumul.c  Cumul.p 
## ------------------------------------------------- 
##   2 >  4       3      2    0.12        2     0.12 
##   4 >  6       5      1    0.06        3     0.19 
##   6 >  8       7      3    0.19        6     0.38 
##   8 > 10       9      1    0.06        7     0.44 
##  10 > 12      11      4    0.25       11     0.69 
##  12 > 14      13      2    0.12       13     0.81 
##  14 > 16      15      2    0.12       15     0.94 
##  16 > 18      17      1    0.06       16     1.00

Dùng test

shapiro.test(df$wt)
## 
##  Shapiro-Wilk normality test
## 
## data:  df$wt
## W = 0.96213, p-value = 0.7006

2.3 Mô tả đặc điểm tải trọng

library(table1)
table1(~ wt | group, data = df, render.continuous = c(. = "Mean (SD)", . = "Median [Q1, Q3]"))
A
(N=7)
B
(N=9)
Overall
(N=16)
wt
Mean (SD) 8.57 (4.24) 11.9 (3.95) 10.4 (4.29)
Median [Q1, Q3] 10.0 [5.00, 11.5] 12.0 [8.00, 16.0] 11.0 [7.00, 13.3]

2.4 Thực hiện phép kiểm t

t.test(A, B)
## 
##  Welch Two Sample t-test
## 
## data:  A and B
## t = -1.6, df = 12.554, p-value = 0.1345
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
##  -7.813114  1.178194
## sample estimates:
## mean of x mean of y 
##  8.571429 11.888889
t.test(wt ~ group, data = df)
## 
##  Welch Two Sample t-test
## 
## data:  wt by group
## t = -1.6, df = 12.554, p-value = 0.1345
## alternative hypothesis: true difference in means between group A and group B is not equal to 0
## 95 percent confidence interval:
##  -7.813114  1.178194
## sample estimates:
## mean in group A mean in group B 
##        8.571429       11.888889

2.5 Thực hiện bootstrap

library(simpleboot)
## Simple Bootstrap Routines (1.1-7)
library(boot)
b = two.boot(A, B, mean, R = 1000)
boot.ci(b)
## BOOTSTRAP CONFIDENCE INTERVAL CALCULATIONS
## Based on 1000 bootstrap replicates
## 
## CALL : 
## boot.ci(boot.out = b)
## 
## Intervals : 
## Level      Normal              Basic         
## 95%   (-7.300,  0.381 )   (-7.206,  0.396 )  
## 
## Level     Percentile            BCa          
## 95%   (-7.031,  0.571 )   (-7.796,  0.211 )  
## Calculations and Intervals on Original Scale
hist(b, breaks = 50)

Việc 6. Ghi lại tất cả các hàm/lệnh trên và chia sẻ lên tài khoản rpubs (https://rpubs.com/ThachTran/1354649)