Relation of cognitive impairment and depression to quality of life in multiple sclerosis patients

The objectives of the present study were to determine the role of cognitive and mood disorders as determinants of health-related quality of life (HRQOL) in multiple sclerosis (MS), as well as to evaluate the validity of self-assessed HRQOL in cognitively impaired patients and the agreement between self-assessed and proxy-reported HRQOL. The study included 204 MS inpatients and outpatients seen between April and September 1997 at three participating centers. The MS quality of life 54 (MSQOL-54) was explained to the patients by a neurologist who also assisted them to complete the questionnaire. A proxy version of the MSQOL-54 was completed independently by each patient's designated proxy. The mean age of the patients was 43 years; the mean expanded disability status scale (EDSS) score was 4.5. Cognitively compromised patients had considerable difficulties in completing the questionnaire, and gave a high percentage of missing and inconsistent items. Depressive symptoms and age had the most important influence on patients' HRQOL. The level of agreement between self-assessed and proxy-reported HRQOL was moderate to substantial for most scales, with proxy informants rating patients as slightly more impaired. Although the patient should be the best informant concerning HRQOL, information from a proxy respondent may be preferable in patients with severe cognitive impairment.