st: count number of events within a time, when entry is lagged

["Miller, Ann C." <Ann_Miller@hms.harvard.edu>]

Dear Statalist, 

I'm trying to determine what proportion of patients received lab tests per protocol (ie at least 1 time a month for 6 months). My dataset (currently wideform but easily transferred to long) includes the variables patient id, treatment start date, lab date1-labdate57, ast1-ast57 alt1-alt57 creatinine1-creatinine57 and so on. Some of the patients' first labs are not defined as lab1. Sometimes, the patients' first labs are lab 2, but for other patients, the first lab will be lab6 or lab14 or something. In addition, not all labs have ast, alt or creatinine values. Some labs were done for other things.

I would like to design a program that will get me the following information; 
How many patients received a test for ast, alt and creatinine in all 6 of the months after they started treatment? 

I'd be very grateful for any suggestions. Many thanks!
--Ann


Ann C. Miller, PhD, MPH
Research Associate
Department of Global Health and Social Medicine
Harvard Medical School


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