Quality of reporting and nature of harms in clinical trials on supervised exercise in patients with rheumatoid arthritis or axial spondyloarthritis

To describe the quality of reporting and the nature of reported harms in clinical studies on the effectiveness of supervised exercises in patients with rheumatoid arthritis (RA) or axial spondyloarthritis (axSpA). We performed a systematic review, searching eight databases up to February 2023. Randomized controlled trials (RCTs) evaluating supervised exercises in adults with RA or axSpA were considered eligible. Data on harms were extracted according to the CONSORT Harms 2022 Checklist. Among others, it was recorded if harms were prespecified or non-prespecified. Moreover, the nature of reported harms was listed. Forty RCTs were included for RA and 25 for axSpA, of which 29 (73%) and 13 (52%) reported information on harms. In 13 (33%) RCTs in RA and four (16%) in axSpA, the collection of harms outcomes was described in the methods section. Prespecified outcomes were reported by eight (RA) and two (axSpA) RCTs. Non-specified harms outcomes were reported by six (RA) and four (axSpA) RCTs. Prespecified harms outcomes included measures of pain, disease activity, inflammation, and structural joint changes. The nature of non-prespecified harms outcomes varied largely, with pain being most common. A considerable proportion of trials on supervised exercise in RA or axSpA does not or inadequately report harms outcomes. Pain was the most commonly reported prespecified or non-specified harm. For a considerate interpretation of the balance between benefits and harms of supervised exercise in RA or axSpA, use of the CONSORT Harms 2022 Checklist for the design, conduct and reporting of trials is advocated.