ICNARC study

Hypothesis 1

This has both direct care and supernumerary nurses. Not used in final paper.

ICU mortality

summary(H1.icu <- lmer(diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + 
    N.dc.perbed + N.supernum.perbed + num.consult.perbed + intensivist + meanap2probuk + 
    I(avyulos/100) + (1 | trust.code), data = dta, family = binomial(), na.action = na.omit, 
    subset = ss8), digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      N.supernum.perbed + num.consult.perbed + intensivist + meanap2probuk +      I(avyulos/100) + (1 | trust.code) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  23178 23272 -11578    23156
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.081    0.285   
## Number of obs: 37969, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)          -1.3386     0.2088    -6.4  1.4e-10 ***
## IMlo                  0.9665     0.0123    78.8  < 2e-16 ***
## prop.occ.c            0.2362     0.0948     2.5   0.0127 *  
## mean.daily.transfer   0.8840     0.3726     2.4   0.0177 *  
## N.dc.perbed          -0.0708     0.0264    -2.7   0.0074 ** 
## N.supernum.perbed     0.0293     0.0887     0.3   0.7412    
## num.consult.perbed   -0.2380     0.0983    -2.4   0.0155 *  
## intensivistYes       -0.1660     0.1076    -1.5   0.1228    
## meanap2probuk        -0.0647     0.1412    -0.5   0.6469    
## I(avyulos/100)        0.3887     0.1483     2.6   0.0087 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p N.spr. nm.cn. intnsY mnp2pr
## IMlo         0.019                                                        
## prop.occ.c  -0.291 -0.005                                                 
## mn.dly.trns -0.064  0.014  0.049                                          
## N.dc.perbed -0.352 -0.018 -0.134 -0.154                                   
## N.sprnm.prb  0.011 -0.008 -0.043 -0.124 -0.001                            
## nm.cnslt.pr -0.318 -0.021 -0.047  0.217 -0.172 -0.104                     
## intensvstYs -0.046 -0.013 -0.016 -0.180 -0.177  0.154  0.001              
## meanap2prbk -0.233 -0.016 -0.016 -0.032  0.025  0.012  0.021 -0.031       
## I(vyls/100) -0.658 -0.001  0.008 -0.033 -0.219 -0.156  0.273  0.103  0.027

Hospital mortality

summary(H1.hosp <- lmer(diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + 
    N.dc.perbed + N.supernum.perbed + num.consult.perbed + intensivist + meanap2probuk + 
    I(avyulos/100) + (1 | trust.code), data = dta, family = binomial(), na.action = na.omit, 
    subset = ss8), digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      N.supernum.perbed + num.consult.perbed + intensivist + meanap2probuk +      I(avyulos/100) + (1 | trust.code) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  30196 30290 -15087    30174
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0691   0.263   
## Number of obs: 37390, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -0.22930    0.18592    -1.2   0.2175    
## IMlo                 0.96148    0.01086    88.6   <2e-16 ***
## prop.occ.c           0.22216    0.08075     2.8   0.0059 ** 
## mean.daily.transfer  1.00813    0.34068     3.0   0.0031 ** 
## N.dc.perbed         -0.05182    0.02353    -2.2   0.0276 *  
## N.supernum.perbed    0.00432    0.08071     0.1   0.9573    
## num.consult.perbed  -0.20688    0.08846    -2.3   0.0193 *  
## intensivistYes      -0.12984    0.09756    -1.3   0.1832    
## meanap2probuk        0.03261    0.12048     0.3   0.7866    
## I(avyulos/100)       0.24648    0.13437     1.8   0.0666 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p N.spr. nm.cn. intnsY mnp2pr
## IMlo         0.056                                                        
## prop.occ.c  -0.278 -0.004                                                 
## mn.dly.trns -0.065  0.018  0.044                                          
## N.dc.perbed -0.343 -0.012 -0.127 -0.153                                   
## N.sprnm.prb  0.004 -0.010 -0.041 -0.125  0.006                            
## nm.cnslt.pr -0.312 -0.013 -0.043  0.220 -0.197 -0.105                     
## intensvstYs -0.054 -0.010 -0.013 -0.177 -0.178  0.152  0.004              
## meanap2prbk -0.229 -0.009 -0.012 -0.030  0.027  0.012  0.021 -0.032       
## I(vyls/100) -0.664 -0.012  0.007 -0.034 -0.227 -0.152  0.270  0.106  0.027

Hypothesis 2

ICU

summary(H2.icu <- lmer(diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + 
    N.dc.perbed + num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) + 
    (1 | trust.code), data = dta, family = binomial(), na.action = na.omit, 
    subset = ss8), digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  23176 23261 -11578    23156
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0809   0.284   
## Number of obs: 37969, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)          -1.3394     0.2087    -6.4  1.4e-10 ***
## IMlo                  0.9665     0.0123    78.8  < 2e-16 ***
## prop.occ.c            0.2375     0.0947     2.5   0.0121 *  
## mean.daily.transfer   0.8991     0.3695     2.4   0.0149 *  
## N.dc.perbed          -0.0708     0.0264    -2.7   0.0074 ** 
## num.consult.perbed   -0.2346     0.0977    -2.4   0.0163 *  
## intensivistYes       -0.1714     0.1063    -1.6   0.1067    
## meanap2probuk        -0.0653     0.1412    -0.5   0.6436    
## I(avyulos/100)        0.3964     0.1464     2.7   0.0068 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr
## IMlo         0.019                                                 
## prop.occ.c  -0.291 -0.005                                          
## mn.dly.trns -0.063  0.013  0.044                                   
## N.dc.perbed -0.352 -0.018 -0.134 -0.156                            
## nm.cnslt.pr -0.319 -0.022 -0.052  0.206 -0.173                     
## intensvstYs -0.049 -0.012 -0.009 -0.164 -0.179  0.017              
## meanap2prbk -0.234 -0.016 -0.016 -0.030  0.025  0.022 -0.034       
## I(vyls/100) -0.664 -0.002  0.002 -0.054 -0.222  0.261  0.130  0.029

Hospital

summary(H2.hosp <- lmer(diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + 
    N.dc.perbed + num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) + 
    (1 | trust.code), data = dta, family = binomial(), na.action = na.omit, 
    subset = ss8), digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  30194 30280 -15087    30174
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0691   0.263   
## Number of obs: 37390, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)          -0.2293     0.1859    -1.2   0.2173    
## IMlo                  0.9615     0.0109    88.6   <2e-16 ***
## prop.occ.c            0.2223     0.0807     2.8   0.0059 ** 
## mean.daily.transfer   1.0103     0.3379     3.0   0.0028 ** 
## N.dc.perbed          -0.0518     0.0235    -2.2   0.0276 *  
## num.consult.perbed   -0.2064     0.0879    -2.3   0.0189 *  
## intensivistYes       -0.1306     0.0964    -1.4   0.1754    
## meanap2probuk         0.0325     0.1205     0.3   0.7874    
## I(avyulos/100)        0.2476     0.1328     1.9   0.0622 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr
## IMlo         0.056                                                 
## prop.occ.c  -0.278 -0.005                                          
## mn.dly.trns -0.065  0.017  0.039                                   
## N.dc.perbed -0.344 -0.012 -0.126 -0.154                            
## nm.cnslt.pr -0.313 -0.014 -0.048  0.210 -0.197                     
## intensvstYs -0.055 -0.009 -0.007 -0.161 -0.181  0.021              
## meanap2prbk -0.229 -0.009 -0.011 -0.029  0.026  0.022 -0.034       
## I(vyls/100) -0.671 -0.013  0.001 -0.054 -0.229  0.259  0.132  0.029

Hypothesis 3

ICU

H3.icu <- update(H2.icu, . ~ . + I(N.dc.perbed^2))
summary(H3.icu)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + I(N.dc.perbed^2) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  23178 23272 -11578    23156
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0798   0.282   
## Number of obs: 37969, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -1.27683    0.31532    -4.0  5.1e-05 ***
## IMlo                 0.96649    0.01227    78.8  < 2e-16 ***
## prop.occ.c           0.23588    0.09487     2.5   0.0129 *  
## mean.daily.transfer  0.90581    0.36850     2.5   0.0140 *  
## N.dc.perbed         -0.09835    0.10837    -0.9   0.3641    
## num.consult.perbed  -0.22918    0.09969    -2.3   0.0215 *  
## intensivistYes      -0.17160    0.10573    -1.6   0.1046    
## meanap2probuk       -0.06717    0.14126    -0.5   0.6344    
## I(avyulos/100)       0.39945    0.14601     2.7   0.0062 ** 
## I(N.dc.perbed^2)     0.00269    0.01028     0.3   0.7937    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.023                                                        
## prop.occ.c  -0.242 -0.006                                                 
## mn.dly.trns  0.018  0.014  0.038                                          
## N.dc.perbed -0.786 -0.018  0.032 -0.115                                   
## nm.cnslt.pr -0.043 -0.019 -0.066  0.218 -0.251                            
## intensvstYs -0.052 -0.012 -0.007 -0.166 -0.017  0.010                     
## meanap2prbk -0.179 -0.016 -0.013 -0.033  0.038  0.014 -0.033              
## I(vyls/100) -0.384 -0.001 -0.003 -0.048 -0.122  0.270  0.127  0.026       
## I(N.dc.p^2)  0.752  0.014 -0.067  0.080 -0.970  0.217 -0.027 -0.033  0.070

Hospital

H3.hosp <- update(H2.hosp, . ~ . + I(N.dc.perbed^2))
summary(H3.hosp)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + I(N.dc.perbed^2) 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  30196 30290 -15087    30174
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.069    0.263   
## Number of obs: 37390, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -0.22582    0.28521    -0.8   0.4285    
## IMlo                 0.96148    0.01086    88.6   <2e-16 ***
## prop.occ.c           0.22223    0.08080     2.8   0.0059 ** 
## mean.daily.transfer  1.01072    0.33894     3.0   0.0029 ** 
## N.dc.perbed         -0.05339    0.09823    -0.5   0.5867    
## num.consult.perbed  -0.20603    0.08999    -2.3   0.0220 *  
## intensivistYes      -0.13066    0.09640    -1.4   0.1753    
## meanap2probuk        0.03247    0.12053     0.3   0.7877    
## I(avyulos/100)       0.24788    0.13301     1.9   0.0624 .  
## I(N.dc.perbed^2)     0.00015    0.00926     0.0   0.9871    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.045                                                        
## prop.occ.c  -0.222 -0.005                                                 
## mn.dly.trns  0.020  0.017  0.035                                          
## N.dc.perbed -0.790 -0.013  0.022 -0.116                                   
## nm.cnslt.pr -0.038 -0.011 -0.058  0.222 -0.253                            
## intensvstYs -0.055 -0.009 -0.005 -0.163 -0.019  0.015                     
## meanap2prbk -0.174 -0.010 -0.009 -0.032  0.038  0.014 -0.033              
## I(vyls/100) -0.387 -0.013 -0.003 -0.048 -0.118  0.266  0.130  0.026       
## I(N.dc.p^2)  0.759  0.011 -0.053  0.082 -0.971  0.213 -0.025 -0.033  0.065

Hypothesis 4

ICU

H4.icu <- update(H2.icu, . ~ . + IMlo * N.dc.perbed)
summary(H4.icu, digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + IMlo:N.dc.perbed 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  23172 23266 -11575    23150
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0813   0.285   
## Number of obs: 37969, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -1.32184    0.20900   -6.32  2.5e-10 ***
## IMlo                 1.08366    0.04910   22.07  < 2e-16 ***
## prop.occ.c           0.23586    0.09463    2.49   0.0127 *  
## mean.daily.transfer  0.90089    0.36999    2.43   0.0149 *  
## N.dc.perbed         -0.07242    0.02639   -2.74   0.0061 ** 
## num.consult.perbed  -0.23794    0.09797   -2.43   0.0152 *  
## intensivistYes      -0.16182    0.10646   -1.52   0.1285    
## meanap2probuk       -0.06886    0.14129   -0.49   0.6260    
## I(avyulos/100)       0.39142    0.14654    2.67   0.0076 ** 
## IMlo:N.dc.perbed    -0.02334    0.00941   -2.48   0.0131 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.037                                                        
## prop.occ.c  -0.290 -0.008                                                 
## mn.dly.trns -0.065  0.005  0.044                                          
## N.dc.perbed -0.351 -0.029 -0.135 -0.154                                   
## nm.cnslt.pr -0.320 -0.019 -0.052  0.207 -0.172                            
## intensvstYs -0.047  0.033 -0.009 -0.164 -0.180  0.016                     
## meanap2prbk -0.234 -0.014 -0.016 -0.031  0.025  0.022 -0.034              
## I(vyls/100) -0.665 -0.013  0.002 -0.053 -0.221  0.261  0.129  0.029       
## IMl:N.dc.pr -0.034 -0.968  0.007 -0.002  0.027  0.014 -0.037  0.011  0.013

Hospital

H4.hosp <- update(H2.hosp, . ~ . + IMlo * N.dc.perbed)
summary(H4.hosp, digits = 3)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + IMlo:N.dc.perbed 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  30196 30289 -15087    30174
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0691   0.263   
## Number of obs: 37390, groups: trust.code, 65
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -0.20029    0.18860   -1.06   0.2882    
## IMlo                 0.99991    0.04338   23.05   <2e-16 ***
## prop.occ.c           0.22174    0.08066    2.75   0.0060 ** 
## mean.daily.transfer  1.00750    0.33804    2.98   0.0029 ** 
## N.dc.perbed         -0.05726    0.02424   -2.36   0.0182 *  
## num.consult.perbed  -0.20744    0.08802   -2.36   0.0184 *  
## intensivistYes      -0.12788    0.09647   -1.33   0.1850    
## meanap2probuk        0.03175    0.12048    0.26   0.7922    
## I(avyulos/100)       0.24735    0.13280    1.86   0.0625 .  
## IMlo:N.dc.perbed    -0.00770    0.00839   -0.92   0.3588    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.177                                                        
## prop.occ.c  -0.275 -0.009                                                 
## mn.dly.trns -0.067 -0.005  0.039                                          
## N.dc.perbed -0.369 -0.240 -0.121 -0.146                                   
## nm.cnslt.pr -0.312 -0.016 -0.048  0.210 -0.187                            
## intensvstYs -0.049  0.028 -0.007 -0.161 -0.183  0.020                     
## meanap2prbk -0.227 -0.009 -0.011 -0.029  0.027  0.022 -0.034              
## I(vyls/100) -0.662 -0.006  0.001 -0.054 -0.222  0.259  0.132  0.029       
## IMl:N.dc.pr -0.168 -0.968  0.008  0.009  0.245  0.013 -0.031  0.007  0.003

Hypothesis 5

ICU

H5.icu <- update(H4.icu, . ~ . + ave.cost.nurse + ratio.pbq.wte)
summary(H5.icu)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedicu ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + ave.cost.nurse + ratio.pbq.wte + IMlo:N.dc.perbed 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  22404 22515 -11189    22378
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0797   0.282   
## Number of obs: 36760, groups: trust.code, 63
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -1.31730    0.31566   -4.17    3e-05 ***
## IMlo                 1.08494    0.05001   21.69   <2e-16 ***
## prop.occ.c           0.28074    0.09684    2.90   0.0037 ** 
## mean.daily.transfer  0.90085    0.37054    2.43   0.0150 *  
## N.dc.perbed         -0.07844    0.02748   -2.85   0.0043 ** 
## num.consult.perbed  -0.26982    0.10105   -2.67   0.0076 ** 
## intensivistYes      -0.16805    0.10816   -1.55   0.1203    
## meanap2probuk       -0.04808    0.14329   -0.34   0.7372    
## I(avyulos/100)       0.40048    0.14757    2.71   0.0067 ** 
## ave.cost.nurse       0.00502    0.00905    0.55   0.5791    
## ratio.pbq.wte       -0.16013    0.14383   -1.11   0.2656    
## IMlo:N.dc.perbed    -0.02358    0.00963   -2.45   0.0144 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.039                                                        
## prop.occ.c  -0.175 -0.005                                                 
## mn.dly.trns  0.035  0.006  0.049                                          
## N.dc.perbed -0.335 -0.033 -0.141 -0.182                                   
## nm.cnslt.pr -0.092 -0.022 -0.047  0.222 -0.175                            
## intensvstYs -0.138  0.029 -0.012 -0.159 -0.180  0.004                     
## meanap2prbk -0.147 -0.013 -0.017 -0.029  0.021  0.023 -0.035              
## I(vyls/100) -0.508 -0.015  0.001 -0.052 -0.225  0.232  0.157  0.029       
## ave.cst.nrs -0.626 -0.003 -0.026 -0.125  0.167 -0.237  0.065 -0.010  0.063
## rati.pbq.wt -0.355 -0.030 -0.005  0.015 -0.007  0.108  0.159 -0.007  0.086
## IMl:N.dc.pr -0.039 -0.968  0.004 -0.003  0.031  0.016 -0.033  0.009  0.015
##             av.cs. rt.pb.
## IMlo                     
## prop.occ.c               
## mn.dly.trns              
## N.dc.perbed              
## nm.cnslt.pr              
## intensvstYs              
## meanap2prbk              
## I(vyls/100)              
## ave.cst.nrs              
## rati.pbq.wt -0.090       
## IMl:N.dc.pr  0.005  0.029

Hospital

H5.hosp <- update(H4.hosp, . ~ . + ave.cost.nurse + ratio.pbq.wte)
summary(H5.hosp)
## Generalized linear mixed model fit by the Laplace approximation 
## Formula: diedhosp ~ IMlo + prop.occ.c + mean.daily.transfer + N.dc.perbed +      num.consult.perbed + intensivist + meanap2probuk + I(avyulos/100) +      (1 | trust.code) + ave.cost.nurse + ratio.pbq.wte + IMlo:N.dc.perbed 
##    Data: dta 
##  Subset: ss8 
##    AIC   BIC logLik deviance
##  29177 29287 -14575    29151
## Random effects:
##  Groups     Name        Variance Std.Dev.
##  trust.code (Intercept) 0.0703   0.265   
## Number of obs: 36183, groups: trust.code, 63
## 
## Fixed effects:
##                     Estimate Std. Error z value Pr(>|z|)    
## (Intercept)         -0.26036    0.30069   -0.87   0.3865    
## IMlo                 0.99861    0.04416   22.61   <2e-16 ***
## prop.occ.c           0.25401    0.08266    3.07   0.0021 ** 
## mean.daily.transfer  0.99241    0.34440    2.88   0.0040 ** 
## N.dc.perbed         -0.05723    0.02541   -2.25   0.0243 *  
## num.consult.perbed  -0.23438    0.09222   -2.54   0.0110 *  
## intensivistYes      -0.13265    0.09962   -1.33   0.1830    
## meanap2probuk        0.02843    0.12230    0.23   0.8162    
## I(avyulos/100)       0.25317    0.13563    1.87   0.0619 .  
## ave.cost.nurse       0.00643    0.00914    0.70   0.4821    
## ratio.pbq.wte       -0.12827    0.13195   -0.97   0.3310    
## IMlo:N.dc.perbed    -0.00767    0.00859   -0.89   0.3719    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1 
## 
## Correlation of Fixed Effects:
##             (Intr) IMlo   prp.c. mn.dl. N.dc.p nm.cn. intnsY mnp2pr I(/100
## IMlo         0.130                                                        
## prop.occ.c  -0.156 -0.007                                                 
## mn.dly.trns  0.047 -0.003  0.044                                          
## N.dc.perbed -0.339 -0.241 -0.126 -0.175                                   
## nm.cnslt.pr -0.052 -0.016 -0.041  0.231 -0.200                            
## intensvstYs -0.150  0.025 -0.010 -0.159 -0.179  0.005                     
## meanap2prbk -0.136 -0.008 -0.014 -0.028  0.025  0.023 -0.035              
## I(vyls/100) -0.496 -0.007  0.000 -0.054 -0.225  0.224  0.162  0.028       
## ave.cst.nrs -0.664 -0.011 -0.025 -0.136  0.164 -0.258  0.079 -0.008  0.076
## rati.pbq.wt -0.339 -0.021 -0.005  0.018 -0.005  0.109  0.161 -0.007  0.082
## IMl:N.dc.pr -0.125 -0.968  0.006  0.007  0.246  0.013 -0.028  0.006  0.004
##             av.cs. rt.pb.
## IMlo                     
## prop.occ.c               
## mn.dly.trns              
## N.dc.perbed              
## nm.cnslt.pr              
## intensvstYs              
## meanap2prbk              
## I(vyls/100)              
## ave.cst.nrs              
## rati.pbq.wt -0.086       
## IMl:N.dc.pr  0.012  0.021

Plots

ICU mortality

ggplot(death.dta[ix, ], aes(x = icu, y = prop.died.icu)) + geom_point(colour = "blue", 
    shape = 15) + labs(list(x = "", y = "Proportion died")) + scale_x_continuous(labels = NULL) + 
    opts(axis.ticks = theme_blank())

plot of chunk icuplot

Hospital mortality

ggplot(death.dta, aes(x = icu, y = prop.died.hosp)) + geom_point(colour = "blue", 
    shape = 15) + labs(list(x = "", y = "Proportion died")) + scale_x_continuous(labels = NULL) + 
    opts(axis.ticks = theme_blank())

plot of chunk hospplot

IMlo density

ggplot(dta, aes(x = IMlo)) + geom_density() + geom_hline(aes(yintercept = 0), 
    colour = "white") + xlim(c(-7, 7)) + ylab("Density") + xlab("IM log odds")
## Warning: Removed 96 rows containing non-finite values (stat_density).

plot of chunk density

Staffing levels

ggplot(staff.dta2, aes(x = ICU, y = Number, fill = Staff)) + geom_bar(stat = "Identity", 
    position = "dodge") + labs(list(x = "", y = "Number")) + scale_x_continuous(labels = NULL) + 
    opts(axis.ticks = theme_blank())

plot of chunk staffplot

Effect plot

plot of chunk effectsetup