Analysis of adverse events attribution and reporting in cancer clinical trials: A systematic review

We systematically reviewed the quality of AEs reports in published oncology trials analyzing also the bias in the attribution process. We searched MEDLINE, PubMed (2000-2019) selecting randomized, double-blind, placebo-controlled, and phase 3 cancer trials using exclusively targeted therapy or immunotherapy-related drugs. The proportion of publications with complete AE reports (including both all-cause and drug-related AE data) and the AEs attribution ratio (patients with drug-related over all-cause AE) were investigated. Among 60 trials (38,174 patients) included, 40 (66.6 %) presented an incomplete report of AEs attribution. Journals with the lowest impact factor were significantly associated with deficient reports of grade 3 4 AEs (p = 0.02). Under placebo administration, the median incidence of all-grade drug-related AEs was 49 % (IQR 39-56). The median attribution ratio for all-grade AEs in the active and placebo arms was 88.9 % (IQR 79.8-93) and 53.9 % (IQR 43.4-60.9), respectively. The AEs reporting and attribution process appear to be more unreliable than expected.

Automated summary

The study systematically reviewed the quality of adverse events reports in oncology trials and found that the reporting and attribution process were more unreliable than expected. A high proportion of trials did not provide complete adverse event attribution reports, and journals with lower impact factors were associated with deficient reporting of grade 3-4 adverse events.