Global prevalence of psychiatric in- and out-patient treatment following hospital-presenting self-harm: a systematic review and meta-analysis

Background: Hospital-treated self-harm is common, costly, and strongly associated with suicide. Whilst effective psychosocial interventions exist, little is known about what key factors might modify the clinical decision to refer an individual to psychiatric in- and/or out-patient treatment following an episode of hospital-treated self-harm. Methods: We searched five electronic databases (CENTRAL, CDSR, MEDLINE, Embase, and PsycINFO) until 3 January 2023 for studies reporting data on either the proportion of patients and/or events that receive a referral and/or discharge to psychiatric in- and/or outpatient treatment after an episode of hospital-treated self-harm. Pooled weighted prevalence estimates were calculated using the random effects model with the Freedman-Tukey double arcsine adjustment in R, version 4.0.5. We also investigated whether several study-level and macro-level factors explained variability for these outcomes using random-effects meta-regression. The protocol of this review was pre-registered with PROSPERO (CRD42021261531). Findings: 189 publications, representing 131 unique studies, which reported data on 243,953 individual participants who had engaged in a total of 174,359 episodes of self-harm were included. Samples were drawn from 44 different countries. According to World Bank classifications, most (83.7%) samples were from high income countries. Across the age range, one-quarter of persons were referred for inpatient psychiatric care and, of these, around one-fifth received treatment. Just over one-third were referred to outpatient psychiatric care, whilst around half of those referred received at least one treatment session across the age range. Event rate estimates were generally of a lower magnitude. Subgroup analyses found that older adults (mean sample age: ≥60 years) may be less likely than young people (mean sample age: ≤25 years) and adults (mean sample age: >25 years to <60 years) to be referred for outpatient psychiatric care following self-harm. More recent studies were associated with a small increase in the proportion of presentations (events) that were referred to, and received, psychiatric outpatient treatment. No macro-level factor explained between-study heterogeneity. Interpretation: There is considerable scope for improvement in the allocation and provision of both in- and out-patient psychiatric care following hospital-presenting self-harm, particularly considering that the period after discharge from general hospitals represents the peak risk period for repeat self-harm and suicide. Given the marked between-study heterogeneity, the basis for allocation of aftercare treatment is therefore not yet known and should be further studied. Funding: There was no specific funding for this review.