Abstract
BACKGROUND: Recent studies indicate the need to examine how the gut microbiota-brain axis is implicated in pain, sensory reactivity and gastro-intestinal symptoms in autism spectrum disorder (ASD), but no scale exists that assesses all these constructs simultaneously. METHODS: We created a pool of 100 items based on the real-world experience of autistic people, and a multidisciplinary team and stakeholders reduced this pool to 50 items assessing pain, sensory hypersensitivity, and sensory hyposensitivity. In the present study, we present this new assessment tool, the Pain and Sensitivity Reactivity Scale (PSRS), and examine its psychometric properties in a sample of 270 individuals with autism spectrum disorder (ASD; mean age = 9.44, SD = 4.97), of which almost half (45%) had intellectual disability (ID). RESULTS: A factorial model of three factors (pain, hyporeactivity, and hyperreactivity) and five specific factors for sensory hypo- and hyperreactivity, respectively, fitted the data well. Good to excellent internal consistency and adequate test-retest reliability was found for most PSRS scales. Sound psychometric properties were found in individuals with and without ID. Correlations with other measures of sensory sensitivity and pain indicated sound convergent validity. CONCLUSIONS: PSRS shows promise as a reliable measure to analyze pain and sensory reactivity in autistic people regardless of whether they have ID or not. The measure overcomes several limitations of previous assessment tools and includes variables that are important for the understanding of the gut microbiota-brain axis in ASD.