Financial conflicts of interest and their association with outcome and quality of fibromyalgia drug therapy randomized controlled trials.

Aims: To evaluate the association of financial conflicts of interest (FCOI) with the characteristics, outcome and reported methodological quality of fibromyalgia drug therapy randomized controlled trials (FM-RCTs).

Methods: A cross-sectional study of original, parallel-group, drug therapy FM-RCTs published between 1997 and 2011 from Medline and Cochrane Central Register of Controlled Trials was conducted. Two reviewers independently assessed each RCT for funding source, authors' FCOI(s), study characteristics, reporting of methodological measures important for internal validity and outcome (positive [statistically significant result favoring experimental drug for the primary outcome] or non-positive).