datasets (version 3.3)

infert: Infertility after Spontaneous and Induced Abortion

Description

This is a matched case-control study dating from before the availability of conditional logistic regression.

Usage

infert

format

rll{ 1. Education 0 = 0-5 years 1 = 6-11 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 1-83 8. stratum number 1-63}

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)
}