datasets (version 3.3.1)

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

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

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)
}