INTRODUCTION Up to 10% of adolescents report self-harm in the previous year. Non-fatal repetition is common (18% in 1 year), death from any cause shows a fourfold and suicide a 10-fold excess. Despite the scale of the problem, there is insufficient evidence for effective interventions for self-harm. Those who self-harm do so for a variety of different reasons. Different treatments may be more effective for subgroups of adolescents; however, little is known about which subgroups are appropriate for further study. This protocol outlines a systematic review and individual participant data meta-analysis (IPD-MA) to identify subgroups of adolescents for which therapeutic interventions for self-harm show some evidence of benefit. METHODS AND ANALYSIS A systematic literature search was conducted in August 2019 (including Cochrane Library, Embase, trial registers and other databases). An update search is planned. Study selection will identify randomised controlled trials examining interventions to reduce self-harm in adolescents who have self-harmed and presented to services. Identified research teams will be invited to contribute data and form a collaborative group. Two-stage IPD-MA will be used to evaluate effectiveness of different therapeutic interventions compared with any active or non-active control on repetition of self-harm, general psychopathology, depression, suicidal ideation, quality of life and death. Subgroup analyses will identify adolescent subgroups in whom different therapeutic interventions may be more effective. Meta-regression will explore moderating study and intervention effects. Sensitivity analyses will incorporate aggregate data from studies lacking IPD and test the robustness of results to methods for handling missing data, within-study clustering, non-adherence and study quality. ETHICS AND DISSEMINATION Ethical approval is provided by the University of Leeds, Faculty of Medicine and Health Ethics Committee (18-098). Outcomes will inform research recommendations and will be disseminated internationally through the collaborative group, a service user advisory group, open-access peer-reviewed publication and conference presentations. PROSPERO REGISTRATION NUMBER CRD42019152119.
Reducing Self-harm in Adolescents. An individual participant data meta-analysis (RISA-IPD): systematic review protocol.