Infertility after Spontaneous and Induced Abortion
This is a matched casecontrol study dating from before the
availability of conditional logistic regression.
Usage
infert
Format
1.  Education  0 = 05 years 
  1 = 611 years 
  2 = 12+ years 
2.  age  age in years of case 
3.  parity  count 
4.  number of prior  0 = 0 
 induced abortions  1 = 1 
  2 = 2 or more 
5.  case status  1 = case 
  0 = control 
6.  number of prior  0 = 0 
 spontaneous abortions  1 = 1 
  2 = 2 or more 
7.  matched set number  183 
8.  stratum number  163 
Note
One case with two prior spontaneous abortions and two prior induced
abortions is omitted.
Source
Trichopoulos et al (1976)
Br. J. of Obst. and Gynaec. 83, 645–650.
Examples
require(stats)
model1 < glm(case ~ spontaneous+induced, data = infert, family = binomial())
summary(model1)
## adjusted for other potential confounders:
summary(model2 < glm(case ~ age+parity+education+spontaneous+induced,
data = infert, family = binomial()))
## Really should be analysed by conditional logistic regression
## which is in the survival package
if(require(survival)){
model3 < clogit(case ~ spontaneous+induced+strata(stratum), data = infert)
print(summary(model3))
detach() # survival (conflicts)
}
