Moderators of Improvements in Fatigue Impact After a Self-management Intervention in Multiple Sclerosis: A Secondary Analysis of a Randomized Controlled Trial.

ABSTRACT: Fatigue is one of the most common and disabling symptoms of multiple sclerosis. A recent randomized controlled trial comparing a fatigue self-management program and a general multiple sclerosis education program found that both programs improved fatigue in participants with multiple sclerosis. Participants were randomized to a self-management program (fatigue: take control, n = 109) or a multiple sclerosis education program (multiple sclerosis: take control, n = 109). This secondary analysis of that trial used multilevel moderation analysis to examine moderators of treatment-related effects on fatigue (Modified Fatigue Impact Scale) from baseline through the 6-mo follow-up. The following potential treatment moderators were examined: age, sex, cohabitation/marital status, and baseline levels of self-efficacy, depression symptoms, and sleep quality. Cohabitation status (living with or without a spouse/partner) interacted with intervention group and time to predict fatigue impact (P = 0.04). Fatigue: take control participants who lived with a spouse/partner showed a marginal effect in greater rate of improvement in fatigue compared with those who lived alone (P = 0.08). However, rates of improvement in fatigue in multiple sclerosis: take control participants were similar in those living with or without a spouse/partner. These findings suggest that living with a spouse or partner may facilitate benefit from self-management interventions for multiple sclerosis-related fatigue. Future research should investigate the contribution of supportive others in self-management of fatigue in multiple sclerosis.