The Flexibility Scale: A Parent-Report Inventory of Flexibility Skills in Children with Autism Spectrum Disorders without ID

Friday, May 13, 2016: 11:30 AM-1:30 PM
Hall A (Baltimore Convention Center)
J. F. Strang1, L. Kenworthy2, L. G. Anthony3, B. E. Yerys4, K. Hardy5 and G. Wallace6, (1)Children's National Medical Center, Silver Spring, MD, (2)Children's Research Institute, Children's National Medical Center, Rockville, MD, (3)Children's National Medical Center, Rockville, MD, (4)The Center for Autism Research, Philadelphia, PA, (5)Neuropsychology, Children's National Medical Center, Rockville, MD, (6)The George Washington University, Washington, DC
Background:  Restricted, repetitive behaviors and interests (RRBI) comprise one of two core symptom domains in autism spectrum disorders (ASD). Existing RRBI measures are limited in their utility to measure RRBI symptoms dimensionally. The Autism Diagnostic Interview is a widely used diagnostic evaluation of RRBI symptoms and has been inappropriately used as a quantitative measure. The Behavior Rating Inventory of Executive Function provides quatitative measurement of cognitive and behavioral flexibility, and has consistently indentified flexibility deficits in ASD, but its eight items do not measure possible subcomponents of cognitive/behavioral flexibility. A novel measure, the Flexibility Scale (FS) targets broad flexibility characteristics in ASD using a larger set of items with the goal of increasing power and specificity when describing the inflexibility phenotype in ASD without ID.

Objectives:  Evaluate the factor structure of the FS in children with ASD.

Methods:  The original 50-item FS was developed through an iterative process based on known RRBI/flexibility characteristics in ASD without ID. Parents of 227 children with ASD (age 7-14) completed the FS. Polychoric exploratory factor analysis (EFA) and assessments of internal consistency were conducted.

Results:  Minimum Average Partial and Parrallel Analysis tests indicated best fit with a 5-factor model accounting for 45% of the variance. Items with factor correlations falling below .4 were eliminated. Ten international ASD/executive function experts evaluated significantly cross-loaded items for factor placement or removal, and generated descriptions of the factors based on item set and known ASD flexibility characteristics. The resulting 29-item questionnaire has 5 factors: Routine/Rituals, Transitions/Change, Special Interests, Social Flexibility, and Generativity.

Conclusions:  These results suggest that RRBI/flexibility characteristics in ASD without ID are multi-dimensional. If confirmed, this factor structure has important implications for the phenotypes of RRBI in ASD without ID, including intervention development and measurement.