Longitudinal 7-year follow-up of chronic pain in persons with multiple sclerosis in the community

Abstract
The aim of this work is to examine the course and impact of chronic pain and pain-related disability in persons with multiple sclerosis (pwMS) over a 7-year period in the Australian community employing a longitudinal, cross-sectional study using structured interviews and validated measures. The intensity of chronic pain was assessed with the visual analogue scale (VAS); the chronic pain grade (CPG) classified pain severity using scores for both pain intensity and pain-related disability, and the assessment of quality of life (AQoL) questionnaire assessed impact on participatory domains. Of the 74 pwMS assessed at 7-year follow-up (T2), 53 (71.6 %) were female, with average age of 55.6 years, and median time since diagnosis of 16.5 years. At T2, 13 (13.8 %) more participants reported chronic pain compared with baseline assessment (T1), (61 vs. 74). Although there were no significant differences on average pain intensity rating between T1 and T2 (p = 0.65), more participants at T2 reported higher rates of pain (13.1 vs. 28.4 %). At T2, participants reported greater disability limiting their daily activities due to pain (16.2 vs. 0 %), and more deterioration and dependency suggested by the AQoL domains of “Independent living” (p < 0.001) and “Physical senses” (p = 0.013). At T2, pwMS used less pharmacological medication but accessed more “other” therapy to cope with their chronic pain. This study provides longitudinal insight into the complex multidimensional chronic pain-related disability in pwMS over a longer period. Improved clinician understanding of the course of chronic pain, early intervention, and patient self-management may decrease pain-related disability and contribute to their overall well-being.