R: Studies on the Length of Hospital Stay of Stroke Patients
dat.normand1999
R Documentation
Studies on the Length of Hospital Stay of Stroke Patients
Description
Results from 9 studies on the length of the hospital stay of stroke patients under specialized care and under conventional/routine (non-specialist) care.
Usage
dat.normand1999
Format
The data frame contains the following columns:
study
numeric
study number
source
character
source of data
n1i
numeric
number of patients under specialized care
m1i
numeric
mean length of stay (in days) under specialized care
sd1i
numeric
standard deviation of the length of stay under specialized care
n2i
numeric
number of patients under routine care
m2i
numeric
mean length of stay (in days) under routine care
sd2i
numeric
standard deviation of the length of stay under routine care
Details
The 9 studies provide data in terms of the mean length of the hospital stay (in days) of stroke patients under specialized care and under conventional/routine (non-specialist) care. The goal of the meta-analysis was to examine the hypothesis whether specialist stroke unit care will result in a shorter length of hospitalization compared to routine management.
Source
Normand, S. T. (1999). Meta-analysis: Formulating, evaluating, combining, and reporting. Statistics in Medicine, 18, 321–359.
Examples
### load data
dat <- get(data(dat.normand1999))
### calculate mean differences and corresponding sampling variances
dat <- escalc(measure="MD", m1i=m1i, sd1i=sd1i, n1i=n1i, m2i=m2i, sd2i=sd2i, n2i=n2i, data=dat)
dat
### meta-analysis of mean differences using a random-effects model
res <- rma(yi, vi, data=dat)
res
### meta-analysis of standardized mean differences using a random-effects model
res <- rma(measure="SMD", m1i=m1i, sd1i=sd1i, n1i=n1i, m2i=m2i, sd2i=sd2i, n2i=n2i,
data=dat, slab=source)
res
### draw forest plot
forest(res, xlim=c(-7,5), alim=c(-3,1), cex=.8)
text(-7, 11, "Study/Source", pos=4, cex=.8)
text( 5, 11, "Observed SMD [95% CI]", pos=2, cex=.8)