Psychometric evaluation of a revised version of the body appreciation scale-2 for autistic adults (BAS-2A)

Emerging evidence points to unique conceptualisations of positive body image in autistic individuals. However, there are no existing measures of positive body image that have been developed or validated for use with autistic adults. To rectify this, we developed a revised version of the BAS-2 - the BAS-2A - and examined its factorial validity and psychometric properties in a sample of autistic adults from the United Kingdom. Based on the results of exploratory factor analysis and scale purification, we extracted a 12-item, unidimensional model of BAS-2A scores in a first split-subsample (n = 273). Confirmatory factor analysis supported the unidimensional model of BAS-2A scores in a second split-subsample (n = 277). BAS-2A scores presented adequate composite reliability, measurement invariance across gender identity, and patterns of construct validity. For both women and men, BAS-2A scores correlated positively with self-esteem, well-being, quality of life, and adaptive coping, and inversely with dietary restraint, weight/shape overvaluation, body dissatisfaction, and depression. Finally, BAS-2A scores demonstrated incremental validity, predicting self-esteem over-and-above body dissatisfaction. However, temporal stability of the BAS-2A over three weeks was not supported. These results support the BAS-2A as a psychometrically robust measure of body appreciation for use in autistic adults from the United Kingdom.