The Work and Social Adjustment Scale: Psychometric properties and validity among males and females, and outpatients with and without personality disorders.

The Work and Social Adjustment Scale (WSAS) is an outcome measure assessing degree of functional impairment. Its psychometric properties, validity and sensitivity to change have been supported in several studies. However, no explicit psychometric or validity study of WSAS has been performed on data from a large sample of psychiatric outpatients, with and without personality disorders. The aim of this study was therefore to provide additional knowledge of the properties of WSAS in such a sample. The material comprised data from 1371 patients, from 15 different units participating in the Norwegian Network of Personality-Focused Treatment Programs. Psychometric properties of the scale, such as measurement invariance among males and females, longitudinal invariance, as well as associations with other clinical measures and sensitivity to change were analysed. The results confirm that WSAS constitutes a reliable, unidimensional and gender invariant measure, sensitive to change and to severity of mental distress. Although highly associated with levels of depression, WSAS measures a clinically important aspect of impairment.