About the Authors

Tjeerd-Pieter van Staa

Tjeerd.vanstaa@GPRD.com

Affiliations General Practice Research Database, London, United Kingdom, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands

Hubert G. Leufkens

Affiliation Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands

Bill Zhang

Affiliation General Practice Research Database, London, United Kingdom

Liam Smeeth

Affiliation London School of Hygiene & Tropical Medicine, London, United Kingdom

Competing Interests

TPvS and BZ: The General Practice Research Database receives funding from the Medicines and Healthcare products Regulatory Agency, pharmaceutical companies, universities, and contract research organizations. TPvS and HGML: The Utrecht Institute for Pharmaceutical Sciences at Utrecht University has received unrestricted funding for pharmacoepidemiological research from GlaxoSmithKline, Novo Nordisk, the private-public funded Top Institute Pharma (http://www.tipharma.nl; includes co-funding from universities, government, and industry), the Dutch Medicines Evaluation Board, and the Dutch Ministry of Health. LS is funded by a Wellcome Trust Senior Research Fellowship in Clinical Science.

Author Contributions

ICMJE criteria for authorship read and met: TPVS HGL BZ LS. Agree with the manuscript's results and conclusions: TPVS HGL BZ LS. Designed the experiments/the study: TPVS HGL BZ LS. Analyzed the data: TPVS BZ. Wrote the first draft of the paper: TPVS. Contributed to the writing of the paper: TPVS HGL BZ LS.