Selective outcome reporting across psychopharmacotherapy randomized controlled trials

Selective reporting impairs the valid interpretation of trials and leads to bias with regards to the clinical evidence. We aimed to examine factors associated with selective reporting in psychopharmacotherapy trials and thus enable solutions to prevent such selective reporting in the future.

We retrieved all registry records of trials investigating medication for depressive, bipolar and psychotic disorders. Multivariate logistic regression was performed with selective reporting as outcome, and funding source, psychiatric disorder, year of study start date, participating centers, and anticipated sample size as explanatory variables, after testing for multicollinearity. Adjusted odds ratios (AOR) were calculated. Two-sided Fisher exact test was used to compare the proportions of newly added positive primary outcomes with the proportions of positive results in the overall group of primary outcomes.

Of 151 included trials (N = 94,303 participants), 21 (14%) showed irregularities between registered and published primary outcomes. Higher odds of such irregularities were associated with non-industry-funded RCTs (AOR 5.3; p = 0.014) and trials investigating major depressive disorder (AOR 12.7; p = 0.024) or schizophrenia (AOR 14.5; p = 0.016; Table 1).

We demonstrate discrepancies between trial registrations and publications across RCTs investigating debilitating psychiatric disorders, especially in non-industry funded RCTs.