Abstract
BACKGROUND: Males are three times more likely to die by suicide than females. The biggest risk factor for suicide is self-harm. Limited evidence suggests that psychosocial interventions (PSIs) for self-harm may be less effective for males than females. We aimed to establish whether this is the case by conducting the first systematic review specifically comparing PSIs for self-harm in clinical and non-clinical settings in males compared to females. METHODS: We conducted a systematic review and meta-analysis using data from trials identified in two Cochrane reviews of PSIs for self-harm published in 2021, and updated their searches in: CENTRAL; MEDLINE; Embase; and PsycINFO - up to 15.05.2024. Studies were eligible if they: included participants who had self-harmed within the past six months; had ≥1 male and ≥1 female in the intervention arm; evaluated the effectiveness of a PSI; were randomised-controlled trials; and collected data on an eligible outcome. Data by sex was extracted and/or requested; and appraised using the Cochrane risk of bias tool for randomised trials. The primary outcome was: repetition of self-harm post-treatment - analysed on an intention-to-treat basis, where possible. PROSPERO registration number: CRD42020225630. FINDINGS: 108 trials were identified. We obtained outcome data by sex post-treatment for 46 trials, that involved 15,405 participants. 11,723 (76.1%) were female. Intervention males were significantly more likely to repeat self-harm than intervention females (301/2062 (14.6%) vs 599/4166 (14.4%): risk ratio 1.21, 95% CI 1.03-1.43; n = 6228; k = 32; I(2) = 31%). Eight trials were considered high risk of bias. Omitting them did not materially affect the result. PSIs were more effective than comparator conditions for females, but not for males. INTERPRETATION: PSIs for self-harm appear to be more effective for females than for males. As males are more likely to die by suicide, PSIs should better address the needs of males who harm themselves. FUNDING: National Institute for Health and Care Research ARC North Thames.