Standard reporting strategy for all trials evaluating: ▶ medicinal drugs or medical devices (including complementary, alternative medicines) ▶ psychological or behavioural interventions (including digital therapeutics) ▶ surgical procedures ▶ physical therapies

Proportion of people experiencing, and frequency of, serious and non‐serious adverse events during and after the intervention (reported cumulatively and separately), as individuals may experience more than one adverse event at any one time. For surgical trials, this will be during the intra‐ and postoperative period

Causality for serious adverse events*

Causality for non‐serious adverse events, if feasible

Practical considerations: ▶ adverse event/serious adverse event data collection by a blinded investigator, where possible/appropriate ▶ for trials involving follow‐up at multiple time points (eg, > 1 year), avoid duplication of adverse event data collection and ensure the wording in the data collection tool or study questionnaire clearly avoids statements such as, “did you experience any adverse event since commencing the study versus since last completing the study questionnaire?”

^*Adverse events or serious adverse events deemed to have a “reasonable possibility of a causal relationship” ⁷ with an intervention should be clearly labelled as such in the trial report/publication (ie, adverse reaction or serious adverse reaction, respectively).