Title stata.com stptime — Calculate person-time, incidence rates, and SMR Syntax Menu Description Options Remarks and examples Stored results References Also see Syntax

stptime [ if] [ , options] options Main at(numlist) trim by(varname) Options per(#) dd(#) smr(groupvar ratevar) using(filename) level(#) noshow Advanced jackknife title(string) output(filename [ , replace]) Description compute person-time at specified intervals; default is to compute overall person-time and incidence rates exclude observations ≤ minimum or> maximum of at() compute incidence rates or SMRs by varname units to be used in reported rates number of decimal digits to be displayed use groupvar and ratevar in using() dataset to calculate SMRs specify filename to merge that contains smr() variables set confidence level; default is level(95) do not show st setting information jackknife confidence intervals label output table with string save summary dataset as filename; use replace to overwrite existing filename You must stset your data before using stptime; see [ST] stset. by is allowed; see [D] by. fweights, iweights, and pweights may be specified using stset; see [ST] stset