Physical Activity Adoption and Maintenance Among Breast Cancer Survivors: A Randomized Trial of Peer Mentoring.

BACKGROUND Peer support can extend the reach of physical activity (PA) interventions. In previous studies, peer support via weekly counseling calls increased PA at 3 and 6 months among breast cancer survivors, compared to contact control. However, effects were attenuated at 6 months. Interventions targeting PA maintenance among cancer survivors are limited. Hence, we extended prior work to identify effective PA maintenance interventions. PURPOSE Following a 3-month PA intervention, the study compared the effects of three 6-month interventions on PA at 12 months. METHODS One hundred and sixty-one inactive breast cancer survivors participated in a 12-month randomized controlled trial. Intervention delivery was uniform for the first 3-months: all participants received a weekly call with their peer coach to encourage PA. Following month 3, participants self-monitored PA and received feedback reports (Reach Plus) or additionally received, a monthly phone call (Reach Plus Phone), or weekly text message (Reach Plus Message). Moderate-to-vigorous PA (MVPA) was measured using self-report (7 Day PAR) and accelerometry at baseline, 3, 6, 9, and 12 months. RESULTS At 3 months, there were significant within group increases in self-reported and objectively measured MVPA with no between-group differences (ps > .05). At 6 months, adjusted longitudinal models showed that Reach Plus Message reported an additional 23.83 (SD = 6.33, f2 = .12) min/week of MVPA and Reach Plus Phone reported an additional 18.14 min/week (SD = 5.15, f2 =.16) versus Reach Plus. Results were similar at 9 months. At 12 months, Reach Plus Message and Reach Plus Phone both out-performed Reach Plus (ps = .04 and .05 respectively and effect sizes f2 = .11 and f2 = .21 respectively). Accelerometer data showed similar patterns: Reach Plus Message and Reach Plus Phone out-performed Reach Plus at 6 (f2 = .20) and 9 months (f2 = .09). CONCLUSION Phone calls from peer mentors and text messaging can support PA maintenance among breast cancer survivors. CLINICAL TRIAL INFORMATION ClinicalTrials.Gov NCT02694640.