Reliability and validity of a health-related quality of life battery for evaluating outpatient antidepressant treatment

Abstract

This study was designed to evaluate the reproducibility, validity and responsiveness of a health-related quality of life (HRQOL) battery that was assembled for the evaluation of antidepressant therapy. The Montgomery-Asberg Depression Rating Scale was used to measure severity of depression. The HRQOL battery contained measures of energy and fatigue, social behaviour, cognitive function, home and work role function, and general well-being (i.e., health perceptions, life satisfaction) selected from previously developed and validated instruments. The clinical investigators and research nurses reported on difficulty in using the HRQOL battery. Most patients were able to complete the questionnaire without problems within 10 min. Reproducibility was very good with intraclass correlation coefficients ranging from 0.74 to 0.97. The HRQOL scales showed evidence of good concurrent validity. The scales were moderately correlated with MADRS scores (r = 0.30-0.62). The magnitude of these correlations indicate that HRQOL scales are related to depression measures, but they are not alternative measures of depression. Changes in MADRS scores were associated with changes in all scales, except for work behaviour, indicating that improvements in depression ratings also resulted in improvements in health status and well-being. The HRQOL scales included in this study were found to be reliable, reproducible, and valid and no appreciable burden was placed on patients or investigators participating in the study. With the exception of the Work Behaviour scale, the HRQOL scales were very responsive to changes in depression severity. This brief HRQOL instrument can provide a comprehensive assessment of the outcomes of antidepressant treatment.