IMPACT: A Randomized Controlled Trial of an mHealth Physical Activity Intervention for Young Adult Cancer Survivors

Abstract

Purpose: The IMPACT trial evaluated a theory-based mobile physical activity (PA) intervention on total PA (primary) and moderate-to-vigorous (MVPA) at 6 months in a nationwide sample of young adult cancer survivors (YACS). Methods: YACS (N=280) were randomized to either an intervention group or a self-help (control) group. All participants received digital tools (activity tracker, smart scale, Facebook group) and an individual videochat session. Intervention participants also received a 6-month mHealth program with components to promote increased PA (behavioral lessons, adaptive goal-setting, tailored feedback, tailored text messages, Facebook group prompts). PA was assessed via accelerometry and online questionnaire (Godin Leisure Time Exercise Questionnaire) at baseline and 6 months. Using linear mixed models and an intention-to-treat approach, we tested for group differences in changes from baseline to 6 months, adjusting for education, time since diagnosis, age, and accelerometer wear time. Results: Of 280 YACS (M=33.4 (SD 4.8) yrs, 81.8% women, 23.2% racial/ethnic minority individuals), 92.9% completed 6-month measures. Device-measured total PA min/wk (i.e., sum of light, moderate, and vigorous PA) increased from a mean of 1974.3 (SD=673.9) to 2024.3 (686.7) at 6 months in the intervention group (p=.26) and from 1814.9 (704.5) to 1877.7 (758.2) in the control group (p=.43), with no difference between groups (p=.84). Both groups increased MVPA min/wk over 6 months; increases were 24.7 min/wk (95% CI: 14.8, 34.6; p<.0001) in the intervention versus 11.4 min/wk (95% CI: 1.4, 21.4; p=.02) in the control (p=.07 between groups). Increases in MVPA were 99.7% and 41.6% over baseline in the intervention and control groups, respectively. Increases in self-reported total PA were significant; 123.3 min/wk (95 CI%: 94.5, 152.1; p<.0001) in the intervention versus 83.40 (95% CI: 49.30, 117.50; p<.0001) in the control (p=.08 between groups). Conclusions: While both groups increased total PA over 6 months, the intervention doubled the increase in MVPA min/wk relative to the control group, which is associated with important health benefits. Future research should examine moderators of effects to identify for whom, and under what conditions, the effectiveness varied.