Extensive selective reporting of quality of life in clinical study reports and publications of placebo-controlled trials of antidepressants

Abstract

Background: Selective reporting of trial results is common.

Objective: To study selective reporting in clinical study reports, company trial registers and publications of quality of life in placebo-controlled trials of antidepressants.

Methods: We compared clinical study reports of four antidepressants (fluoxetine, duloxetine, paroxetine and sertraline) obtained from two European drug regulators, data from online company registers, and publications received or retrieved from Eli Lilly and GlaxoSmithKline. Pfizer was also contacted but did not provide any publications.

Results: We included 15 trials (19,015 pages) and 4717 patients. Six trials had used SF-36, seven EQ-5D and two both instruments. Nine of the 15 CSRs (60%) displayed selective reporting. In the companies' online registers, there was selective reporting for all 15 trials (100%). We received 20 publications from Eli Lilly and retrieved six from the GlaxoSmithKline register. There was selective reporting in 24 of the 26 publications (92%). Despite extensive selective reporting, we found only small differences between placebo and active drugs.

Conclusions: Access to the full raw data from clinical trials and to case report forms for all patients are needed to evaluate the effect of antidepressants on quality of life. Regulatory agencies should refuse to approve drugs or new indications based on incomplete reporting.

Keywords: EQ-5D; Quality of life; SF-36; antidepressants; clinical study reports; placebo; publication bias; selective reporting.