A meta-analysis of intervention effects on challenging behaviour among persons with intellectual disabilities.

BACKGROUND Persons with intellectual disabilities (ID) often show challenging behaviour. We review distinct interventions that are applied to treat these challenging behaviours, and analyse intervention effects and moderating variables. METHODS A literature search was conducted using the databases ERIC, PsycINFO, Web of Science and Medline. A random-effects meta-analysis was carried out, supplemented with sensitivity, subgroup, meta-regression and publication bias analyses. RESULTS Eighty potential articles were identified, from which 30 contained sufficient data to enable statistical meta-analysis. From these 30 studies, 18 described a biological, 13 a psychotherapeutic and nine a contextual intervention, either applied alone or combined. The overall standardised mean difference was 0.671 (SD = 0.051). As shown by sensitivity analysis, this summary effect size is robust. Assessed through subgroup and meta-regression analysis, all tested moderators showed no statistically significant association with the treatment effects. After applying a funnel plot-, a fail-safe N-, and Duval's and Tweedie's trim and fill-analysis, we conclude that our meta-analysis does not suffer much from publication bias effects. CONCLUSIONS Several biological, psychotherapeutic and contextual interventions effectively reduce challenging behaviours among persons with ID.