Investigating the assumptions of the self‐controlled case series method. (2nd November 2017)

• Record Type: Journal Article
• Authors: Whitaker, Heather J.; Ghebremichael‐Weldeselassie, Yonas; Douglas, Ian J.; Smeeth, Liam; Farrington, C. Paddy
• Is Part Of: Statistics in medicine. Volume 37:Number 4(2018)
• Page Start: 643
• Page End: 658
• Publication Date: 2017-11-02
• Subjects: assumptions -- event dependent exposures -- event dependent observation period -- self controlled case series; Medical statistics -- Periodicals; Statistique médicale -- Périodiques; Statistiques médicales -- Périodiques; 610.727
• DOI: 10.1002/sim.7536
• Languages: English
• ISSNs: 0277-6715

Abstract

Abstract : We describe some simple techniques for investigating 2 key assumptions of the self‐controlled case series (SCCS) method, namely, that events do not influence subsequent exposures and that events do not influence the length of observation periods. For each assumption, we propose some simple tests based on the standard SCCS model, along with associated graphical displays. The methods also enable the user to investigate the robustness of the results obtained using the standard SCCS model to failure of assumptions. The proposed methods are investigated by simulations and applied to data on measles, mumps and rubella vaccine, and antipsychotics.