Sleep problems affect not only the wellbeing of children with autism spectrum disorders (ASD) but also the functioning of the entire family unit, and bi-directional influences between child sleep and family functioning are possible. Complex familial factors are seldom considered as predictors of outcome in studies on ASD. The present study aimed at investigating the effect of a Functional Behavioural Assessment (FBA) informed parent-implemented behavioural sleep treatment on ameliorating sleep problems of children with ASD. The present analysis also investigated the impact of components of family complexity on sleep problem severity in these children, in particular how well these components could predict treatment outcomes. To achieve this, the present analysis explored the components that lay underneath the 11 parent/family variables used to operationally define family complexity.

Data from thirty-one children with ASD, aged between 3 and 14.5, and their parents, were analysed. These 31 children completed the treatment phase of a larger study (54 participants) which investigated the effectiveness of a 4-to-8- week home-based behavioural sleep intervention in ameliorating sleep problems in children with ASD. Exploratory factor analysis was used to explore the components that reside underneath the complex family dynamics. Multiple regression analysis was utilised to investigate whether components of family complexity could predict treatment outcomes.

The results of pre- and post-comparisons indicated the efficacy of behavioural sleep treatment in reducing sleep problem severity in the children at post-treatment, short-term follow-up and long-term follow up. Secondary outcomes included improved paternal depression, paternal anxiety, maternal anxiety and maternal sleep quality. Factor analysis indicated there were three components of family complexity. The three components were paternal wellbeing (paternal mood states and paternal sleep quality), maternal wellbeing (maternal mood states and maternal sleep quality), and parental relationship quality (paternal marital satisfaction and maternal marital satisfaction). Parental relationship quality before treatment was found to be the only significant predictor of treatment outcomes, F (3,19) = 3.86, p =.026.

The evidence of the present study provided stronger support for a bi-directional relationship between child sleep and parental wellbeing. Future research efforts could consider examining the joint effect of child factors and family factors in predicting the treatment outcomes in children with ASD.