Importance: Multiple studies have reported that people with autism spectrum disorder (ASD) are at a higher risk for self-injurious behavior and suicide. However, the magnitude of this association varies between studies.
Objective: To appraise the available epidemiologic studies on the risk of self-injurious behavior and suicidality among children and adults with ASD.
Data sources: PubMed, Embase, CINAHL, PsycINFO, and Web of Science were systematically searched for epidemiologic studies on the association between ASD and self-injurious behavior and suicidality. Databases were searched from year of inception to April through June 2020. No language, age, or date restrictions were applied.
Study selection: This systematic review and meta-analysis included studies with an observational design and compared self-injurious behavior (defined as nonaccidental behavior resulting in self-inflicted physical injury but without intent of suicide or sexual arousal) and/or suicidality (defined as suicidal ideation, suicide attempt, or suicide) in children (aged <20 years) or adults (aged ≥20 years) with ASD.
Data extraction and synthesis: Information on study design, study population, ASD and self-harm definitions, and outcomes were extracted by independent investigators. Study quality was assessed using the Newcastle-Ottawa Scale. Overall summary odds ratios (ORs) and 95% CIs were estimated using DerSimonian-Laird random-effects models.
Main outcomes and measures: The ORs for the associations of ASD with self-injurious behavior and suicidality were calculated. Analyses were stratified by study setting and age groups as planned a priori.
Results: The search identified 31 eligible studies, which were of moderate to high quality. Of these studies, 16 (52%) were conducted in children, 13 (42%) in adults, and 2 (6%) in both children and adults. Seventeen studies assessed the association between ASD and self-injurious behavior and reported ORs that ranged from 1.21 to 18.76, resulting in a pooled OR of 3.18 (95% CI, 2.45-4.12). Sixteen studies assessed the association between ASD and suicidality and reported ORs that ranged from 0.86 to 11.10, resulting in a pooled OR of 3.32 (95% CI, 2.60-4.24). In stratified analyses, results were consistent between clinical and nonclinical settings and between children and adults.
Conclusions and relevance: This study found that ASD was associated with a substantial increase in odds of self-injurious behavior and suicidality in children and adults. Further research is needed to examine the role of primary care screenings, increased access to preventive mental health services, and lethal means counseling in reducing self-harm in this population.