Self-management behaviors do not affect remission but mediate between mental health and disease outcomes in a longitudinal study of rheumatoid arthritis

Mental health has been shown to impact rheumatoid arthritis (RA) outcomes and is associated with self-management behaviors. The extent to which mental health impacts outcomes via different self-management behaviours has not been thoroughly investigated. Adult RA patients who were starting a new medication or dosage were recruited to a prospective cohort with follow-ups at 3 and 12-months covering clinical and patient-reported outcomes. The longitudinal relationships between mental health, self-management behaviors (diet, physical activity, sleep, smoking, alcohol, and medication nonadherence), disease outcome, and function were assessed. Self-management behaviors were considered mediators of mental health at baseline on outcomes at 3 and 12 months. Depression did not worsen the odds of EULAR response for the total PHQ at 3 months (OR = 0.96, p = 0.36) or 12 months (OR = 0.99, p = 0.99) nor for the categorical PHQ at 3 months (OR = 0.64, p = 0.34) or 12 months (OR = 0.67, p = 0.44). Anxiety also did not worsen the odds of EULAR response for the total GAD at 3 months (OR = 0.98, p = 0.76) or 12 months (OR1.04, 0.53) nor for the categorical GAD at 3 months (OR = 0.99, p = 0.99) or 12 months (OR = 0.94, p = 0.75). However, depression was associated with the DAS-28 at 3 months (b = 0.22, p = 0.04). Among the self-management behaviors, insomnia was found to be a significant mediator between depression and the WSAS (b = 0.08, p = 0.03) as well as anxiety and the WSAS (b = 0.07, p = 0.03). Alcohol was also a significant mediator between depression and the DAS-28 (b = 0.21, p = 0.04). Mental health was associated with worse quality of life and disease outcomes, but not EULAR response. Self-management behaviors were associated with disease outcomes and mental health.