This is a matched case-control study dating from before the availability of conditional logistic regression.
infert
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 |
# NOT RUN { 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 # } # NOT RUN { if(require(survival)){ model3 <- clogit(case ~ spontaneous+induced+strata(stratum), data = infert) print(summary(model3)) detach() # survival (conflicts) } # }