High reprint orders in medical journals and pharmaceutical industry funding: case-control study.

OBJECTIVES: To assess the extent to which funding and study design are associated with high reprint orders. DESIGN: Case-control study. SETTING: Top articles by size of reprint orders in seven journals, 2002-09. PARTICIPANTS: Lancet, Lancet Neurology, Lancet Oncology (Lancet Group), BMJ, Gut, Heart, and Journal of Neurology, Neurosurgery & Psychiatry (BMJ Group) matched to contemporaneous articles not in the list of high reprint orders. MAIN OUTCOME MEASURES: Funding and design of randomised controlled trials or other study designs. RESULTS: Median reprint orders for the seven journals ranged from 3000 to 126,350. Papers with high reprint orders were more likely to be funded by the pharmaceutical industry than were control papers (industry funding versus other or none: odds ratio 8.64, 95% confidence interval 5.09 to 14.68, and mixed funding versus other or none: 3.72, 2.43 to 5.70). CONCLUSIONS: Funding by the pharmaceutical industry is associated with high numbers of reprint orders.