Impaired health-related quality of life predicts progression of disability in multiple sclerosis

Background and purpose: To determine the value of health-related quality of life (HRQOL) in predicting progression of disability in patients with multiple sclerosis (MS) over a period of 2 years. Methods: Patients with MS were recruited in 13 outpatient clinics in Madrid, Spain. Baseline HRQOL was quantified using the Functional Assessment of MS (FAMS) and disability with Kurtzke Expanded Disability Status (EDSS). A clinical meaningful deterioration of disability was defined as an increased of >= 1 point in baseline EDSS scores of <= 5.5 and an increase of >= 0.5 point in baseline EDSS scores of >= 6.0. We dichotomized the change in disability according to clinical meaningful deterioration (dependent variable) and performed a logistic regression analysis with the tertiles of the FAMS scores (the upper tertile [high HRQOL] was the reference) as independent variable, adjusting by socio-demographic and clinical variables. Results: Out of 371 enrolled patients, 61 patients with MS dropped out during the 2-year follow-up. Of the remaining 310, 94 (30.3%) had clinical meaningful deterioration of disability. The odds of clinical meaningful deterioration of disability were higher as HRQOL decreased with a significant dose-dependent effect. Adjusted odds ratios were 2.61 [95% confidence interval (CI) 95% = 1.12-6.09], [middle tertile vs. upper tertile (reference)]; and 3.27 (95% CI = 1.31-8.18), (lower tertile vs. upper tertile). Conclusions: The identification of those patients with MS with poor HRQOL may be important in assessing the risk of future disability progression. Clearly, impaired HRQOL should be one of the primary concerns amongst clinicians who provide treatment to patients affected by MS.