The Prevalence and Correlates of Self-restraint in Individuals with Autism and/or Intellectual Disability: a Systematic Review and Meta-analysis

Abstract

Purpose: Self-restraint, purposeful restriction of one’s own bodily movements is observed in individuals with neurodevelopmental conditions. Case studies and cross-sectional investigations have reported that self-restraint co-occurs with self-injurious behaviour; however, small sample sizes limit understanding of prevalence and function. We aimed to synthesise the existing literature and estimate the pooled prevalence of self-restraint in autistic individuals and/or individuals with intellectual disability, and the pooled effect size with self-injury. Methods: Six databases were systematically searched in accordance with PRISMA guidelines. Results: A total of 21,567 papers were retrieved, with 15 samples from 13 records included in the analyses. The pooled prevalence estimate of self-restraint in individuals with autism and/or intellectual disability was 39%, 95% CI [26.25, 51.59]. Age and presence of autism significantly increased prevalence rates. Pooled prevalence estimates were consistent across gender, presence of intellectual disability, and type of measurement of self-restraint. Meta-analyses of 31 topographies of self-restraint revealed ‘holds or squeezes objects’ and ‘holding onto others, holding onto others’ clothing’ were the most prevalent behaviours amongst those who self-restrained (both 32%). The least prevalent behaviour was ‘chooses mechanical restraint’ (1%). Pooled prevalence estimates of self-restraint in individuals known to self-injure were 34%, 95% CI [21.36, 46.97], and 13%, 95% CI [5.01, 21.43], in individuals who did not self-injure. Self-restraint and self-injurious behaviour were positively correlated, r = 0.21, 95% CI [0.14, 0.27], K = 13. Conclusions: Findings highlight that on average, over one third of individuals with autism and/or intellectual disability show self-restraint. Clinical and theoretical implications of findings are discussed.