EDSS Change Relates to Physical HRQoL While Relapse Occurrence Relates to Overall HRQoL in Patients with Multiple Sclerosis Receiving Subcutaneous Interferon β-1a

Objective. To compare patterns of associations of changes in mental and physical health dimensions of health-related quality of life (HRQoL) over time with relapse occurrence and changes in Expanded Disability Status Scale (EDSS) scores in patients with relapsing multiple sclerosis (RMS). Methods. This 24-month, phase IV, observational study enrolled 334 patients with RMS who received interferon β-1a 44 μg or 22 μg subcutaneously three times weekly. At each 6-month visit, patients completed the Multiple Sclerosis Quality of Life-54 (MSQOL-54) and site investigators assessed EDSS and recorded relapse occurrence. A generalized linear model procedure was used for multivariable analyses (per protocol) that explored unique associations of EDSS score change and relapse occurrence with MSQOL-54 physical health composite score (PCS) and mental health composite score (MCS). Results. HRQoL improved over 2 years among those who completed the study. Occurrence of ≥1 relapse was significantly associated with lower MSQOL-54 PCS and MCS. Changes in EDSS score were significantly associated with MSQOL-54 PCS, but not MCS. Conclusions. HRQoL assessments, particularly those that examine mental health, may provide information on the general health status of patients with RMS that would not be recognized using traditional clinician-assessed measures of disease severity and activity. This trial is registered with ClinicalTrials.gov; identifier: NCT01141751.