Longitudinal correlates of fatigue in multiple sclerosis

Objective To determine the predictors of longitudinal changes in fatigue based on pain, mood, and neurological impairment across multiple sclerosis (MS) subtypes. Background Fatigue is the most common symptom of MS but remains poorly understood. The New York State Multiple Sclerosis Consortium (NYSMSC) database offers a unique opportunity to longitudinally assess a variety of potential fatigue correlates in a very large and diverse MS sample. Design/Methods This study examined baseline and 1-year follow-up data on 2768 patients drawn from the NYSMSC database regarding fatigability, pain, depressive symptoms, MS subtype, and expanded disability status scale (EDSS). Correlates and predictors of fatigue were assessed in correlational and multiple regression analyses. Results Baseline fatigue, pain, and depression accounted for 34.6% of the variance in 1-year follow-up fatigue scores. Fatigue was lower in relapsing-remitting subjects than in other MS subtypes. Fatigue consistently correlated at baseline and follow-up with depressive symptoms, pain severity, and EDSS. Changes in fatigue correlated with changes in other variables. Conclusions Predictors of fatigue at 1 year include baseline fatigue, pain, mood, and EDSS. These symptoms are also correlated at baseline, follow-up, and in change scores. Identifying predictors of fatigue may facilitate patient management. Multiple Sclerosis 2009; 15: 258-261. http://msj.sagepub.com