| % File src/library/datasets/man/infert.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{infert} |
| \docType{data} |
| \alias{infert} |
| \title{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{ |
| \tabular{rll}{ |
| 1. \tab Education \tab 0 = 0-5 years \cr |
| \tab \tab 1 = 6-11 years \cr |
| \tab \tab 2 = 12+ years \cr |
| 2. \tab age \tab age in years of case \cr |
| 3. \tab parity \tab count \cr |
| 4. \tab number of prior \tab 0 = 0 \cr |
| \tab induced abortions \tab 1 = 1 \cr |
| \tab \tab 2 = 2 or more \cr |
| 5. \tab case status\tab 1 = case \cr |
| \tab \tab 0 = control \cr |
| 6. \tab number of prior \tab 0 = 0 \cr |
| \tab spontaneous abortions \tab 1 = 1 \cr |
| \tab \tab 2 = 2 or more \cr |
| 7. \tab matched set number \tab 1-83 \cr |
| 8. \tab stratum number \tab 1-63} |
| } |
| \source{ |
| Trichopoulos \emph{et al} (1976) |
| \emph{Br. J. of Obst. and Gynaec.} \bold{83}, 645--650. |
| } |
| \note{ |
| One case with two prior spontaneous abortions and two prior induced |
| abortions is omitted. |
| } |
| \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 |
| \donttest{if(require(survival)){ |
| model3 <- clogit(case ~ spontaneous+induced+strata(stratum), data = infert) |
| print(summary(model3)) |
| detach() # survival (conflicts) |
| }} |
| } |
| \keyword{datasets} |