Arriving at the empirically based conceptualization of restricted and repetitive behaviors: A systematic review and meta-analytic examination of factor analyses.

An empirically based understanding of the factor structure of the restricted and repetitive behaviors (RRB) domain is a prerequisite for interpreting studies attempting to understand the correlates and mechanisms underpinning RRB and for measurement development. Therefore, this study aimed to conduct a systematic review and meta-analysis of RRB factor analytic studies. Sets of meta-analyses were performed to examine (a) the factor structure of individual RRB instruments, (b) associations between RRB subdomains across instruments, and (c) the association between RRB factors and other variables. Searches for peer-reviewed articles evaluating the factor structure of the RRB domain were performed in PsycINFO (Ovid), Medline (Ovid), and Embase (Ovid). No age, measurement, or informant-type limits were imposed. Quality and risk of bias for individual studies were assessed using relevant COSMIN sections. Among the 53 studies retained for review, 41 examined RRB factor structures among individuals with autism spectrum disorder (ASD) and 12 among non-ASD samples. Meta-analysis of factor correlations provided evidence that the RRB domain encompasses the following eight specific factors: repetitive motor behaviors, insistence on sameness, restricted interests, unusual interests, sensory sensitivity, and repetitive, stereotyped language. Although interrelated, RRB factors were distinct, showing a unique pattern of associations with demographic, cognitive, and clinical correlates. Meta-analyses of the associations between RRB factors and specific correlates, specifically adaptive functioning and communication impairments, should be considered preliminary due to the limited number of studies. Despite limitations, this review provides important insights into the factor structure of the RRB domain and highlights critical conceptual, measurement, and methodological limitations of the current research that will need to be addressed in order to improve our understanding of RRB.

Daily living skills scale: Development and preliminary validation of a new, open-source assessment of daily living skills.

Autistic individuals and individuals with a range of other neurodevelopmental conditions (NDD) often present with lower levels of daily living skills (DLS) when compared to their neurotypical peers. Importantly, lower levels of DLS have been linked to a range of negative outcomes, including lower rates of post-secondary education, lower employment rates, and higher daily support needs across autism and NDD. However, there are currently no open-source informant-reported instruments for capturing key aspects of DLS. This study describes the development, refinement, and initial psychometric evaluation of a new, relatively brief (53-item). Daily Living Skills Scale (DLSS) in a sample of 1,361 children aged 2-17 years, Confirmatory Factor Analysis demonstrated an excellent fit of unidimensional model to the data (CFI = 0.953, TLI = 0.951, RMSEA = 0.073 [95% CI: 0.071-0.074]). The single-factor CFA model showed evidence of measurement invariance of factor loadings, thresholds, and residual variance (strict invariance) across sex, age, race, and ethnicity. Model reliability and internal consistency were excellent (ω = 0.98; α = 0.97). Conditional reliability estimates indicated very good reliability (= 0.80) for the total DLS scale from very low (θ = -4.2) to high (θ = +2.4) scores. Conceptually derived self-care, homecare, and community participation subscales also showed strong reliability and internal consistency. With further replication, the EFS has excellent potential for wide adoption across research and clinical contexts.