Explaining Physical Activity Maintenance After a Theory-Based Intervention Among Patients With Rheumatoid Arthritis: Process Evaluation of a Randomized Controlled Trial.

Objective: Regular physical activity (PA) benefits patients with rheumatoid arthritis (RA), particularly when maintained over time. Research in this area has largely focused on factors associated with initiating PA, while factors contributing to PA maintenance, particularly after lifestyle interventions, have received less attention. This study examined whether higher levels of autonomous motivation, self-efficacy for PA, and greater use of self-regulation skills mediated PA initiation and maintenance 6 months after a theory-based motivational interviewing and self-regulation coaching intervention.

Methods: Seventy-eight individuals with RA were randomized to receive either a patient-education session (control group), or the patient-education session plus 1 motivational interview and 2 self-regulation coaching sessions (treatment group). Mediation analyses examined the effects of this intervention on PA initiation and maintenance through the intermediate variables autonomous motivation, self-efficacy for PA, and use of self-regulation skills. Analyses were controlled for age, sex, and previous levels of PA.

Results: The treatment group reported significantly higher autonomous motivation and greater use of self-regulation skills than controls at posttreatment. Increases in PA from baseline to posttreatment were not mediated by any intermediate variables. However, maintenance of PA from posttreatment to followup (6 months later) was mediated by greater autonomous motivation and use of self-regulation skills.

Conclusion: Greater autonomous motivation and use of self-regulation skills predict maintenance of PA following a motivational interviewing and self-regulation coaching intervention. In promoting PA among patients with RA, supporting patient autonomy and teaching self-regulation skills, which focus attention on achieving PA goals, may improve long-term maintenance of PA.