Background: Treatment- and work-related aspects have been neglected in health-related quality of life (HRQOL) measures in multiple sclerosis (MS). We aimed to develop a brief instrument covering all important impairment-, activity-, participation-, and treatment-related aspects for use in research and practice.
Methods: The 27-item Multiple Sclerosis Quality of Life Questionnaire (MS-QLQ27) was developed using open item collection, a multidisciplinary expert panel, and cognitive pretesting. It was evaluated for reliability, construct validity, and responsiveness with 100 patients presenting with relapse (84 at follow-up ~14 days later). Construct validity was analyzed by correlating the MS-QLQ27 with the disease-specific Hamburg Quality of Life Questionnaire in MS (HAQUAMS) and generic HRQOL instuments. The Expanded Disability Status Scale (EDSS) was used to analyze known-groups validity. Responsiveness was determined as the correlation of changes in MS-QLQ27 scores with changes in validation criteria.
Results: Internal consistency was high (Cronbach α = 0.94 at baseline and 0.93 at follow-up). Convergent validity was supported by direction and magnitude of associations with disease-specific and generic instruments. Correlations with change in convergent criteria were strong, indicating responsiveness. The HAQUAMS showed the strongest associations with the MSQLQ27. The MS-QLQ27 showed the highest effect size compared with other patient-reported outcomes and the EDSS. It successfully distinguished between levels of disease severity.
Conclusions: These results indicate that the MS-QLQ27 is a reliable, valid, and highly responsive instrument for assessing HRQOL during relapse evolution in MS. Its advantages are that it is brief yet comprehensive, covering work- and treatment-related aspects not addressed in previous measures.