Association of author's financial conflict of interest with characteristics and outcome of rheumatoid arthritis randomized controlled trials.

Objectives: To examine the prevalence, types and temporal trends of reported financial conflicts of interest (FCOIs) among authors of drug therapy randomized controlled trials (RCTs) for RA and their association with study outcomes.

Methods: We identified original, non-phase 1, parallel-group, drug therapy RA RCTs published in the years 2002-03, 2006-07, and 2010-11. Two investigators independently obtained trial characteristics data. Authors' FCOIs were classified as honoraria/consultation fees receipt, employee status, research grant, and stock ownership. Multivariable logistic regression was performed to identify whether FCOIs were independently associated with study outcome.

Results: A total of 146 eligible RCTs were identified. Of these, 83 (58.4%) RCTs had at least one author with an FCOI [employee status: 63 (43.2%), honoraria/consultation fees receipt: 49 (33.6%), research grant: 30 (20.5%), and stock ownership: 28 (19.2%)]. A remarkable temporal increase in reporting of honoraria/consultation fees receipt, research grant, and stock ownership was seen. The reporting of any FCOI itself was not associated with positive outcome [50/73 (68.5%) with author FCOI vs 36/52 (69.2%) without author FCOI, P = 0.93]. However, honoraria/consulting fees receipt was independently associated with increased likelihood of a positive outcome [adjusted odds ratio (95% CI) of 3.24 (1.06-9.88)]. In general, trials with FCOIs were significantly more likely to be multicentre, have larger enrolment, use biologic or a small molecule as the experimental intervention, and have better reporting of some methodological quality measures.

Conclusion: FCOI reporting in RA drug RCT authors is common and temporally increasing. Receipt of honoraria/consulting fees was independently associated with a positive study outcome.