Harms are assessed inconsistently and reported inadequately part 1: systematic adverse events

We examined systematic adverse events (AEs) in Part 1 (of 2) of a study describing the assessment and reporting of AEs in clinical trials.

We examined 52 public and nonpublic data sources about trials of quetiapine for bipolar depression using data from the Multiple Data Sources study. We extracted and compared information about systematic AEs (i.e., AEs assessed for all participants) in six prespecified domains: cardiovascular, cholesterol, endocrine, extrapyramidal symptoms, mania, and weight.

Eligible trials did not assess and report the same systematic AEs, and most results were not available in public sources. Overall, public sources reported 159 results, of which 92 of 159 (58%) included sufficient statistical information to calculate the treatment effect and its precision. Nonpublic sources reported 636 results; 630 of 636 (99%) reported sufficient statistical information.

Systematic AEs were defined and analyzed in many ways, which led to many numerical results. Most systematic AEs were not mentioned in public sources. To minimize bias, methods for defining and analyzing potential AEs should be prespecified in trial registers and protocols. All trial results should be publicly available so that stakeholders can compare benefits and AEs. Trials could report core sets of AEs to facilitate decision-making.