Burden of illness of multiple sclerosis: Part II: Quality of life. The Canadian Burden of Illness Study Group.

OBJECTIVE: To measure the quality of life (QoL) of multiple sclerosis (MS) patients in Canada using a generic QoL instrument, the SF-36. METHODS: QoL was assessed in 198 MS patients, recruited from 14 MS Clinics in Canada, and stratified into three levels of disease severity, based on their Expanded Disability Status Scale (EDSS) score. Statistical tests were used to compare QoL scores between severity groups and to identify possible relationships between QoL and patient sociodemographic, clinical and economic parameters. RESULTS: QoL scores for all eight scales of the SF-36 were substantially reduced early in the disease. Compared to the normal population, QoL scores for patients with mild MS were on average 30% lower for all SF-36 scales. With EDSS progression a statistically significant decrease in three of the SF-36 domains (physical function, role-physical, and social function) was observed. There were no significant correlations between patient parameters considered and QoL scores. CONCLUSIONS: QoL of MS patients collapses early in the disease. With EDSS progression, physical functioning scales show further decreases in QoL. The absence of further changes in the mental SF-36 scales may be a reflection of patient adaptation to the disease and/or effective support care. However, the SF-36 instrument may be insensitive to some of the QoL changes in MS and a disease-specific instrument may provide additional information on QoL, particularly at later stages of the disease. This study provides a basis for future research aimed at improving management of MS.