Risk time-window specification and its impact on the assessment of medication-related adverse events

Abstract

Post-marketing studies using medical administrative databases are often conducted to assess medication-related adverse events (AE). The determination of the risk time-window, defined as the period of time during which a medication-related AE could occur, is a crucial and challenging step toward the correct assessment of these AEs. In general, the unknown risk time-window consists of the number of days supplied, TS, for the medication and of a time-window. TW, that starts after TS and during which the medication could still produce AEs. Arguments have been made in favor of both short and long TW, durations. The aim of this thesis is to determine the impact of varying TW values on the assessment of the rate of cardiovascular AEs, using simulated data, and in a real-life example using administrative databases from Quebec. Results indicated that longer TW values tended to bias results toward the null