Long-Term Trends in Pediatric Self-Injury in High-Income Countries: A Systematic Review and Meta-Analysis.

IMPORTANCE: Self-injury, the deliberate act of causing physical harm to oneself either with or without suicidal intent, is a leading cause of emergency department use among young people. Trend data in self-injury are lacking. OBJECTIVE: To provide temporal trends in self-injury rates among children and youth residing in Organization for Economic Co-operation and Development countries. DATA SOURCES: MEDLINE, Embase, Scopus, and PsycINFO and gray literature were searched for articles and reports published in English between January 2000 and December 2024. STUDY SELECTION: Included were regional and national registry-based longitudinal and cross-sectional studies conducted within general populations, comprising individuals aged 24 years and younger, and with at least 5 years of data. Studies were included that measured (1) hospitalization or emergency department or physician visits for self-injury (2) surveys of self-reported self-injury. DATA EXTRACTION AND SYNTHESIS: This study used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline with PROSPERO protocol registration. Articles were independently assessed for quality by 2 individuals. Random-effects meta-analyses were used to calculate overall and sex-specific pooled effect estimates and 95% CIs. MAIN OUTCOMES AND MEASURES: The primary outcome was the relative change in the annual rate of health care encounters for self-injury or from self-reported surveys. RESULTS: A total of 42 studies with a combined population of 234 054 520 individuals at study midpoints were conducted in 12 high-income countries; 35 studies used health care encounter data, and 7 studies used self-reported surveys. Based on health care encounters, there was a 3.5% (95% CI, 1.9-4.9) relative annual increase in self-injury over the study period (2000-2024), which was higher for female individuals (3.6%; 95% CI, 2.3-4.9) than male individuals (1.2%; 95% CI, 0.0-1.8). For self-reported surveys, there was a 2.5% (95% CI, 0.0-5.5) relative annual increase in self-injury. CONCLUSIONS AND RELEVANCE: This systematic review and meta-analysis of 42 studies observed a relative increase in the annual rate of self-injury visits to health care and self-reported self-injury, with variability in baseline rates across studies in 12 high-income countries. Effective, contextually informed, large-scale prevention initiatives are urgently needed to curb the rise in self-injury within high-income countries, particularly among female individuals.