Moderating Effects of Clinical and Social Factors on Fatigue Improvement After an Online Peer-Led Fatigue Self-management Intervention in People With Systemic Sclerosis: A Secondary Analysis of a Randomized Controlled Trial.

Abstract

To examine moderators of intervention effects in fatigue from a randomized controlled trial comparing an online peer-led fatigue self-management intervention to a waitlist control in people with systemic sclerosis (SSc). Secondary analysis of a 12-week, parallel, single-blind randomized controlled trial. Community. Adults with SSc with moderate to severe fatigue (N=173) recruited from SSc specialty centers, a registry, and social media. A 12-week, online, peer-led fatigue self-management intervention was randomized in a 2:1 ratio: intervention (n=115) and waitlist control (n=58). The outcome measure was change in the Functional Assessment of Chronic Illness Therapy-Fatigue scale assessed at baseline, week 6, and week 12. Potential moderators assessed at baseline included demographic, clinical, psychological, and social variables. Baseline levels of informational support moderated the treatment effect to predict change in fatigue at week 12 (P=.015). Participants who had average to high levels of informational support at baseline reported greater improvements in fatigue at week 12 compared with their counterparts in both treatment groups, whereas the between-moderator difference in the intervention group is significantly larger than in the waitlist control. No other variables were found to significantly moderate the outcomes. Participants with baseline average to high informational support experienced greater improvements in fatigue at week 12 compared with their counterparts, particularly in the intervention group. This suggests that higher informational support may enhance coping and emotional reassurance. Future research could tailor fatigue interventions based on baseline informational support to optimize treatment efficacy in diverse SSc populations.