What is already known about the topic?The delivery of evidence-based interventions is an important part of the clinical pathway for many autistic children and their families. However, parents, practitioners, and policymakers face challenges making evidence informed decisions, due to the wide variety of interventions available and the large, and often inconsistent, body of evidence regarding their effectiveness.What this paper adds?This is a comprehensive umbrella review, also known as a 'review of reviews', which examined the range of interventions available, the evidence for their effectiveness, and whether effects were influenced by factors relating to individual children (e.g. chronological age, core autism characteristics, and related skills) or the ways interventions were delivered (by whom and in what setting, format, mode, and amount). There was evidence for positive therapeutic effects for some, but not all, interventions. No single intervention had a positive effect for all child and family outcomes of interest. The influence of child and delivery characteristics on effects was unclear.Implications for practice, research, and policyThe findings provide parents, practitioners, and policymakers with a synthesis of the research evidence to inform decision-making and highlight the importance of individualised approaches in the absence of clear and consistent evidence. The findings also highlight the need to improve consistency and completeness in reporting of research studies, so that the same questions may be answered more comprehensively in the future.
Keywords: autism; evidence; intervention; non-pharmacological; review.