Conclusions
EVENTS
The findings from our analysis suggest three pragmatic approaches to how symptom reporting in antimalarial trials could be improved. Firstly, the reporting of more severe symptoms is less skewed between sites and more likely to be reproducible compared to mild and moderate events. Trialists should therefore distinguish clearly between safety outcomes (severe symptoms) and tolerability outcomes (mild and moderate symptoms), with the latter needing to be interpreted with caution given greater heterogeneity of reporting. Secondly in multi-site studies with varied proportions of reported symptoms between sites, trialists should be clear in the reporting of the uncertainty surrounding their estimates. The range of proportions (rather than or in addition to the mean or median) may be a better way to report pooled results, reflecting the variability. Thirdly symptoms recorded in an intervention arm should be reported in relation to the control arm. A relative change in symptoms in the intervention arm compared to the control arm is much more relevant than simply recording the absolute occurrence of symptoms.