Social Adaptation Self-evaluation Scale (SASS): Psychometric analysis as outcome measure in the treatment of patients with major depression in the remission phase

Abstract

INTRODUCTION: To carry out a psychometric analysis of the Social Adaptation Self-evaluation Scale (SASS), which has been found very promising during first experiences with it in the treatment of depression. METHOD: Patients in the remission phase during treatment for a major depressive episode completed the SASS over a period of 12 weeks, with monthly assessments. For comparison, the Hamilton Depression Scale with the Melancholia Scale (HAM-D/MES) was used as well as a self-reporting questionnaire, the Major Depression Inventory (MDI). In the psychometric analysis both classical tests (e.g. principal component analysis) and modern tests (Mokken analysis with the Loevinger coefficient of homogeneity) were applied. RESULTS: The SASS scale with its 21 items was found to contain at least three factors, of which the first was a general factor; this however explained less than 50% of the variance. A subscale containing the six items with the highest factor loadings was found to be a unidimensional scale. This subscale showed a much higher responsiveness than the total SASS. However, both SASS scales were found to have a lower responsiveness than the Major Depression Inventory (MDI) during the first weeks of treatment. CONCLUSION: The SASS was found to be a multidimensional scale. However, a six-items subscale (covering items with the highest loadings on the first use) was shown to be a unidimensional scale and to have a greater responsiveness than the total SASS, but still lower than the MDI. (Int J Psych Clin Pract 2002; 6: 141-146)