Which symptoms contribute the most to patients’ perception of health in multiple sclerosis?

BACKGROUND Multiple sclerosis is a polysymptomatic disease. Little is known about relative contributions of the different multiple sclerosis symptoms to self-perception of health. OBJECTIVES To investigate the relationship between symptom severity in 11 domains affected by multiple sclerosis and self-rated health. METHODS Multiple sclerosis patients in two multiple sclerosis centers assessed self-rated health with a validated instrument and symptom burden with symptoMScreen, a validated battery of Likert scales for 11 domains commonly affected by multiple sclerosis. Pearson correlations and multivariate linear regressions were used to investigate the relationship between symptoMScreen scores and self-rated health. RESULTS Among 1865 multiple sclerosis outpatients (68% women, 78% with relapsing-remitting multiple sclerosis, mean age 46.38 ± 12.47 years, disease duration 13.43 ± 10.04 years), average self-rated health score was 2.30 ('moderate to good'). Symptom burden (composite symptoMScreen score) highly correlated with self-rated health (r = 0.68, P < 0.0001) as did each of the symptoMScreen domain subscores. In regression analysis, pain (t = 7.00), ambulation (t = 6.91), and fatigue (t = 5.85) contributed the highest amount of variance in self-rated health (P < 0.001). CONCLUSIONS Pain contributed the most to multiple sclerosis outpatients' perception of health, followed by gait dysfunction and fatigue. These findings suggest that 'invisible disability' may be more important to patients' sense of wellbeing than physical disability, and challenge the notion that physical disability should be the primary outcome measure in multiple sclerosis.