Capturing change in restricted and repetitive behaviour in preschoolers with ASD: A comparison of direct behavioural observation and parent report.

This study looked at different ways to measure repetitive behaviours in young children with autism. Researchers compared parent questionnaires with professional observations to see which method better tracks changes over time. They found that parent questionnaires were better at picking up subtle changes in repetitive behaviours. The study identified three patterns: children whose behaviours increased, stayed the same, or decreased over time.

However, different measurement tools often disagreed about which pattern a child followed, suggesting they measure different things.

This longitudinal study compared three methods of measuring restricted and repetitive behaviours (RRB) in 134 toddlers and preschoolers with autism aged 25-65 months. Researchers examined direct observation tools (ADOS-2, BOSCC) versus parent questionnaires (RBS-R) to determine which best captures changes in RRB over time. The RBS-R parent questionnaire identified significantly more reliable changes in RRB severity compared to observation-based measures. Three distinct developmental trajectories were found: increasing, stable, and decreasing RRB severity.

However, there was low overlap between measures in identifying which children belonged to each trajectory group, suggesting different tools capture different aspects of RRB. The findings indicate that dimensional questionnaires may be superior for detecting subtle changes during preschool years.

Clinicians should consider using parent questionnaires like the RBS-R alongside observation measures for comprehensive RRB assessment. Different measures may capture distinct aspects of repetitive behaviours. Understanding individual trajectory patterns can guide intervention planning and monitoring treatment response in preschool-aged children with autism.

Sample characteristics beyond age range not fully described. Study type not specified. Cross-sectional correlations were weak, raising questions about construct validity across measures. Limited information about intervention effects or external factors influencing trajectories.

Restricted and repetitive behaviour (RRB) in autism spectrum disorder (ASD) can be assessed by different measures, which diverge in item quantity, dimensionality or source of information. However, change sensitivity has not been systematically investigated among commonly used measures, albeit its importance for clinical trials and longitudinal studies. Longitudinal data resulting from behavioural observation (Autism Diagnostic Observation Schedule-2, ADOS-2; Brief Observation of Social Communication Change, BOSCC) and parent report (Restricted Behaviour Scale-Revised, RBS-R) was collected for 134 toddlers and preschoolers aged 25-65 months diagnosed with ASD by the Autism Diagnostic Interview-Revised (ADI-R) and ADOS-2. Change sensitivity was estimated using the reliable-change index and developmental trajectories of RRB by linear mixed models and k-means clustering.

The RBS-R identified significantly more reliable change in RRB severity compared to ADOS-2 and BOSCC. For all measures, except the RBS-R self-injurious behaviour subscale, three distinct RRB trajectories were found as follows: increasing, stable and decreasing RRB severity. Overlap was low between trajectory group assignment across measures, as were cross-sectional correlations between ADI-R, ADOS-2, BOSCC and RBS-R. Trajectory group comparisons among measures mostly showed lower baseline RRB severity in the increasing trajectory groups and higher baseline RRB severity in the decreasing trajectory groups.

The trajectory groups did not differ in age or nonverbal IQ across RRB measures, except for the RBS-R compulsive behaviour subscale, which had higher nonverbal IQ in the decreasing trajectory group. The dimensional questionnaire RBS-R compared to ADOS-2 and BOSCC is superior in capturing subtle changes in RRB during preschool age.