title: A meta-analysis of intervention effects on challenging behaviour among persons with intellectual disabilities.
abstract: 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.
authors.affiliation: Centre for Methodology of Educational Research, Department of Educational Sciences, Katholieke Universiteit Leuven, Belgium. Mieke.Heyvaert@ped.kuleuven.be
authors.forename: Mieke
authors.initials: M
authors.lastname: Heyvaert
authors.forename: B
authors.initials: B
authors.lastname: Maes
authors.forename: P
authors.initials: P
authors.lastname: Onghena
mesh_terms: D019958:Attention Deficit and Disruptive Behavior Disorders / Q000628:therapy*; D006801:Humans; D008607:Intellectual Disability / Q000523:psychology* / Q000628:therapy*; D011613:Psychotherapy