To consider the outcome as a dichotomous outcome, the author must determine the number of participants in each intervention group, and the number of participants in each intervention group who experience at least one event (or some other appropriate criterion which classified all participants into one of two possible groups). Any time element in the data is lost through this approach, though it may be possible to create a series of dichotomous outcomes, for example at least one stroke during the first year of follow-up, at least one stroke during the first two years of follow-up, and so on. It may be difficult to derive such data from published reports.