Published Online: August 6, 2012. doi:10.1001/archinternmed.2012.2816
Author Contributions:Study concept and design: Ahmad, Nijpels, Dekker, and Hugtenburg. Acquisition of data: Ahmad and Hugtenburg. Analysis and interpretation of data: Ahmad, Nijpels, Kostense, and Hugtenburg. Drafting of the manuscript: Ahmad and Hugtenburg. Critical revision of the manuscript for important intellectual content: Nijpels, Dekker, Kostense, and Hugtenburg. Statistical analysis: Ahmad, Nijpels, and Kostense. Obtained funding: Hugtenburg. Administrative, technical, and material support: Ahmad. Study supervision: Nijpels, Dekker, and Hugtenburg.
Financial Disclosure: None reported.
Trial Registration: trialregister.nl Identifier: NTR1194
Previous Presentation: This manuscript was presented at the International Conference on Pharmacoepidemiology and Therapeutic Risk Management; August 14-17, 2011; Chicago, Illinois.
Additional Contributions: Maria Ruth Mast, MSc, assisted with data collection and in the development of a checklist of different types of drug-related problems used in the study.