32085
Development of a Brief Screening Tool for Repetitive Behaviors and Restricted Interests
Repetitive behaviors and restricted interests (RB/RIs) have proven a difficult construct to accurately and validly measure, in part due to the heterogeneity of RB/RI symptom presentation by demographic and clinical characteristics. Additional work is needed to understand phenomenology and further refine existing measures.
Objectives:
The present study aimed to (1) use an existing measure of RB/RIs (Repetitive Behavior Scale – Revised; RBS-R) to identify RB/RIs that are present among individuals with ASD regardless of cognitive level, gender, or age and (2) propose a brief screening instrument for RB/RIs.
Methods:
Participants included cross-sectional data compiled from the National Database for Autism Research, Autism Genetic Resource Exchange, and Simons Simplex Collection (N=3203). To evaluate frequency of endorsement across demographic and clinical characteristics, the sample was divided into 6 age and cognitive subgroups (age<6 & NVIQ<70, age 6-12 & NVIQ<70, age>=12 & NVIQ<70, age<6 & NVIQ>=70, age 6-12 & NVIQ>=70, age>=12 & NVIQ>=70), and 3 language subgroups based on ADOS module administered (Module 1 – single words, Module 2 – two word phrases, Module 3/4 - fluent speech). RBS-R item responses were recoded as either symptom present or absent. Items were selected as possible screening items if 50% of 5 of the 6 NVIQ/age subgroups (N=14) and all 3 of the ADOS subgroups (N=5) endorsed the item.
Results:
The sample included N=3203 participants with a diagnosis of ASD. Participants were 84% male, 67% Caucasian, 8.97 years of age on average (SD = 3.85; range 2-33), and had an average NVIQ of 83.36 (SD = 27.26). A total of N=14 of the 43 RBS-R items were endorsed by at least 5 of the 6 NVIQ/age subgroups and N=5 items by all 3 of the ADOS subgroups. The final item set included items that were endorsed by both at least 5 of the 6 age/NVIQ subgroups and all 3 of the ADOS subgroups (N=5). These items included “sensory (e.g., covers eyes)”, “becomes upset if interrupted in what he/she is doing”, “likes the same movie/music played continually”, “resists changing activities/difficulty with transitions”, and “fascination/preoccupation with one subject or activity”. These 5 items represented 3 of the 6 RBS-R subscales (stereotyped behavior, sameness behavior, restricted behavior). If the selection criteria were modified to include items endorsed by 2 of the 3 ADOS subgroups, “eating/mealtime (e.g., eats/drinks items in a set order)”, and “communication/social interaction (e.g., repeats same topics during social conversation)” would also be included (subscale: ritualistic behavior).
Conclusions:
The present study supports the variability in presentation of RB/RIs by age, cognitive level, and language level. Despite the substantial differences in symptom presentation, there are several RB/RIs – notably sensory sensitivity - that are endorsed across individuals with ASD of different ages, cognitive abilities, and language levels. The items have the potential to serve as a more uniform screening tool for assessment of RB/RIs. Future work should confirm the results in other large population-based samples and determine if items can discriminate between ASD and other neuropsychiatric disorders that are characterized by repetitive behaviors (e.g., OCD).