Author Contributions: Dr Giezen had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Giezen, Mantel-Teeuwisse, Straus, Leufkens, Egberts.
Acquisition of data: Giezen, Mantel-Teeuwisse.
Analysis and interpretation of data: Giezen, Mantel-Teeuwisse, Schellekens, Egberts.
Drafting of the manuscript: Giezen, Mantel-Teeuwisse.
Critical revision of the manuscript for important intellectual content: Mantel-Teeuwisse, Straus, Schellekens, Leufkens, Egberts.
Statistical analysis: Giezen, Mantel-Teeuwisse, Egberts.
Administrative, technical, or material support: Giezen, Mantel-Teeuwisse, Egberts.
Study supervision: Mantel-Teeuwisse, Straus, Schellekens, Leufkens, Egberts.
Financial Disclosures: The department employing Drs Giezen, Mantel-Teeuwisse, Leufkens, and Egberts has received unrestricted research grants from GlaxoSmithKline, Organon, Merck, and Novo Nordisk for the conduct of pharmacoepidemiological research. Dr Schellekens reported receiving research grants from Organon, Roche, and Merck-Serono. Dr Straus did not report any financial disclosures.