Now we will talk about how to analyze the hazard period data and control data to estimate the effect of exposure on the outcome. Since there are 2 types of control data, we will also have 2 types of analyses.
If the control data are from a comparable control period, the analysis will be the same as that for a matched case-control study. However, instead of concordant and discordant pairs of study subjects in a matched case-control study, here we will have concordant and discordant pairs of exposures from the hazard period and control period. That is, the pairs are made up of two intervals(hazard period and control period) for each subject, and the pairs are either concordant or discordant for exposure. After arranging the data in a 2 by 2 table as shown in the slide, we can just use the standard method for matched case-control to get the odds ratio.