Leveraging Family Dynamics to Increase the Effectiveness of Incentives for Physical Activity: The FIT-FAM Randomized Controlled Trial
Abstract Background In Singapore, 37% of adults are insufficiently active despite widespread opportunities for physical activity (PA). Research shows that PA can be increased by use of group-based extrinsic incentives. This study evaluates whether a novel incentive design linking children’s incentives to both their own and their parent’s PA (measured via pedometers) can increase parents’ PA without compromising children’s PA. Methods We conducted a two-arm, parallel, open-labelled randomized controlled trial where parent-child dyads were randomly assigned to either (1) rewards to the child contingent on child’s PA (child-based) or (2) rewards to the child contingent on both child’s and parent’s PA (family-based). Parents had to be English-speaking, computer-literate, non-pregnant, full-time employees, aged 25–65 years, and with a participating child aged 7–11 years. Parent-child dyads were randomized within strata (self-reported low vs high weekly PA) into study arms in a 1:1 ratio. Participants were given pedometers to assess daily steps. The primary outcome was the between-arm difference in the change from baseline in parent’s mean steps/day measured by accelerometry at months 6 and 12. Results 159 and 157 parent-child dyads were randomized to the child-based or family-based arms, respectively, and all with outcomes evaluated an intent-to-treat perspective. At month 6, there was a statistically significant 613 steps/day (95% CI: 54–1171) differential in favour of family-based parents. At month 12, the differential was reduced to 369 steps/day (95% CI: -88–1114) and no longer statistically significant. Conclusions Our findings provide evidence that family-based incentive strategies have the potential to improve outcomes at no additional cost but also indicate that more research is needed to identify strategies that encourage long-term behavior change for both parents and children.