Health perceptions and clinical characteristics of relapsing-remitting multiple sclerosis patients: baseline data from an international clinical trial

Objective: Baseline clinical and health-related quality of life (HRQoL) data from a phase 2, multi-site, international, randomized, controlled trial were analyzed to: (1) characterize the health status of patients with relapsing-remitting multiple sclerosis (RRMS), (2) explore cross-sectional relationships between HRQoL and clinical measures, and (3) evaluate differences in HRQoL scores for subsequent validation as minimally important differences (MID). Clinical Trial Registration: www.clinicaltrials.gov, NCT00207727. Research design and methods: Baseline clinical and HRQoL data were selected and analyzed. HRQoL questionnaires included the Short Form-36 (SF-36), Fatigue Severity Scale (FSS), a Patient Assessment of multiple sclerosis (MS) Impact (PAMSI), and MS-specific symptom scales for Bladder and Bowel Control, Cognition, and Sexual Satisfaction. Standard summary statistics described the population while Pearson and Spearman correlations evaluated the baseline association between HRQoL and clinical measures. Cross-sectional estimates of MID in HRQoL scores were derived using several clinical anchors, the PAMSI, and two tests: Tukey multiple comparisons and adjacent mean difference. Results: Patients (n=249) had a mean age of 39.0 (Standard deviation, SD=10.5), 70% were female, 63% resided in Europe, and 96% were Caucasian. Baseline median Expanded Disability Severity Scale (EDSS) was 2.5 range=0.0-6.5); median disease duration was 1.9 years (range=0.1-33.6). The worst baseline mean (normalized) SF-36 scores were for General Health (39.9), Role Physical (40.4), Physical Functioning (41.0), and Vitality (42.7). The worst MS symptom mean scores were for Cognition (6.3) and FSS (4.4). Fatigue scores indicated substantial burden and were consistent with SF-36 Vitality results. Baseline HRQoL scores (SF-36, FSS, MS symptom scales) correlated most with EDSS, Multiple Sclerosis Functional Composite (MSFC), age and disease duration. Lesion count and pre-baseline relapse rate had no meaningful association with HRQoL or other clinical measures. The MID for several HRQoL measures are proposed for confirmation in longitudinal patient datasets. Conclusion: Clinical and HRQoL assessments documented health impairments in physical functioning, fatigue, and cognition among these RRMS patients with relatively short disease duration. HRQoL data varied with clinical measures and contributed new information regarding disease burden. The association between clinical and HRQoL measures was limited to cross-sectional analysis and requires confirmation in longitudinal datasets. These findings reflect an ambulatory, early-stage RRMS population that was mostly European in location or descent. The PAMSI also requires further validation as a measure of patient health status.