Multiple sclerosis: change in health-related quality of life over two years.

BACKGROUND Cross-sectional research has demonstrated poorer function and health-related quality of life (HRQOL) in those with multiple sclerosis (MS) but less is known about change over time. The goals of this study were to measure change in HRQOL and identify factors associated with change. METHODS HRQOL was assessed at baseline and annually over two subsequent years using the Multiple Sclerosis Quality of Life Inventory. Function was assessed using the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Functional Composite. Annualized rate of change was calculated for all twenty outcomes. Mixed effects modeling (univariate followed by multivariate) was used to examine the associations among patient characteristics and the age- and sex-adjusted Physical Component Summary (PCS) and Mental Component Summary (MCS) at study initiation and over the two years of follow-up. RESULTS Of 300 participants, 288 (96%) provided at least one assessment and are included in this analysis. Although 14 of the 20 outcomes showed a mean decline, only two (SF-36 physical function, p=0.018 and the EDSS, p<0.001) were statistically significant. The SF-36 social function showed a significant improvement (p=0.031). Only two variables were significantly associated with a decreased rate of decline or improvement over two years, including being female (PCS, p=0.001) and use of visiting nurse services (MCS, p<0.001). CONCLUSIONS HRQOL is relatively stable over two years of follow-up, particularly for mentally-oriented outcomes. Further research with a longer period of follow-up is needed to provide additional insight into factors associated with change in HRQOL in patients with MS.