title: Reporting cumulative proportion of subjects with an adverse event based on data from multiple studies.
abstract: Experience has shown us that when data are pooled from multiple studies to create an integrated summary, an analysis based on naïvely-pooled data is vulnerable to the mischief of Simpson's Paradox. Using the proportions of patients with a target adverse event (AE) as an example, we demonstrate the Paradox's effect on both the comparison and the estimation of the proportions. While meta analytic approaches have been recommended and increasingly used for comparing safety data between treatments, reporting proportions of subjects experiencing a target AE based on data from multiple studies has received little attention. In this paper, we suggest two possible approaches to report these cumulative proportions. In addition, we urge that regulatory guidelines on reporting such proportions be established so that risks can be communicated in a scientifically defensible and balanced manner.
authors.affiliation: Pfizer, Inc, Kalamazoo, Michigan, USA. christy.j.chuang-stein@pfizer.com
authors.forename: Christy
authors.initials: C
authors.lastname: Chuang-Stein
authors.forename: Mohan
authors.initials: M
authors.lastname: Beltangady
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data*; D002986:Clinical Trials as Topic / Q000706:statistics & numerical data*; D006801:Humans; D015201:Meta-Analysis as Topic; D015233:Models, Statistical; D012107:Research Design