Purpose: Consensus is needed on conceptual foundations, terminology and relationships among the various self-controlled “trigger” study designs that control for time-invariant confounding factors and target the association between transient exposures (potential triggers) and abrupt outcomes. The International Society for Pharmacoepidemiology (ISPE) funded a working group of ISPE members to develop guidance material for the application and reporting of self-controlled study designs, similar to Standards of Reporting Observational Epidemiology (STROBE). This first paper focuses on navigation between the types of self-controlled designs to permit a foundational understanding with guiding principles.
Methods: We leveraged a systematic review of applications of these designs, that we term Self-controlled Crossover Observational PharmacoEpidemiologic (SCOPE) studies. Starting from first principles and using case examples, we reviewed outcome-anchored (case-crossover [CCO], case-time control [CTC], case-case-time control [CCTC]) and exposure-anchored (self-controlled case-series [SCCS]) study designs.
Results: Key methodological features related to exposure, outcome and time-related concerns were clarified, and a common language and worksheet to facilitate the design of SCOPE studies is introduced.
Conclusions: Consensus on conceptual foundations, terminology and relationships among SCOPE designs will facilitate understanding and critical appraisal of published studies, as well as help in the design, analysis and review of new SCOPE studies. This manuscript is endorsed by ISPE.
Bibliographical noteFunding Information:This guidance report was supported by a manuscript proposal grant to Dr. Cadarette from the International Society for Pharmacoepidemiology (ISPE). Authors thank Joann Ban, PharmD, MSc for providing the fluoxetine example in the pharmacology section, and: Drs. Paddy Farrington, Katsiaryna Bykov, Murray Mittleman, Elizabeth Mostofsky, Donald Redelmeier, Samy Suissa; and STRengthening Analytical Thinking in Observational Studies (STRATOS) members Drs. Mitchell Gail and Elizabeth Williamson; for providing insightful comments based on early drafts of this work. This manuscript is endorsed by ISPE.
SMC, MM, JACD, HJW, KNH, MT, GPC and JH report no conflicts of interest. JJG has received salary support from grants from Eli Lilly and Company and Novartis Pharmaceuticals Corporation to Brigham and Women's Hospital and was a consultant to Optum Inc., all for unrelated work. SVW has received salary support from investigator-initiated grants to Brigham and Women's Hospital from Boehringer Ingelheim, Novartis Pharmaceuticals and Johnson & Johnson.
This guidance report was supported by a manuscript proposal grant to Dr. Cadarette from the International Society for Pharmacoepidemiology (ISPE).
Open Access: This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Publishers Copyright: © 2021 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.
Citation: Cadarette, SM, Maclure, M, Delaney, JAC, et al. Control yourself: ISPE-endorsed guidance in the application of self-controlled study designs in pharmacoepidemiology. Pharmacoepidemiol Drug Saf. 2021; 30: 671– 684.