A systematic review of adverse event reporting in companion animal clinical trials evaluating cancer treatment

OBJECTIVE To evaluate methods used to ascertain, define, and report adverse events (AEs) in companion animal clinical trials involving cancer treatment. DESIGN Systematic review. SAMPLE English-language articles describing prospective clinical trials involving dogs and cats with naturally occurring cancer published in peer-reviewed journals between 2008 and 2014. PROCEDURES Reports were identified via MEDLINE and CAB database searches combined with a hand-searching strategy. General article characteristics were abstracted and summarized. Data for AE reporting were collected with a 14-item checklist adapted from the 2004 CONSORT extension for reporting harms. Study characteristics associated with the AE reporting checklist score were identified by means of linear regression analysis. RESULTS 168 articles with data for 6,132 animals were included. Standardized terminology was significantly more likely to be used to describe AEs for trials that included chemotherapy (92/115 [80.0%]) than for trials that did not (16/53 [30.2%]). Median AE reporting checklist score was 5 out of 14 (range, 0 to 12). Poorly reported items included methods and time frame of AE ascertainment, AE data analysis, and reasons for treatment discontinuation and death. Trials with industry funding, a single-arm design, and treatment with chemotherapy were associated with a significantly higher quality of AE reporting. CONCLUSIONS AND CLINICAL RELEVANCE Reporting of adverse events in veterinary clinical trials evaluating cancer treatment was selective and heterogeneous. Harms associated with cancer treatments could be underestimated because of suboptimal collection and reporting of AE data. Findings supported the adoption of a higher standard for AE surveillance and reporting in veterinary patients.