Randomised controlled trial of a financial incentive for increasing the number of daily walking steps: study protocol

INTRODUCTION: Physical activity is one of the major modifiable factors for promotion of public health. Although it has been reported that financial incentives would be effective for promoting health behaviours such as smoking cessation or attendance for cancer screening, few randomised controlled trials (RCTs) have examined the effect of financial incentives for increasing the number of daily steps among individuals in a community setting. The aim of this study is to investigate the effects of financial incentives for increasing the number of daily steps among community-dwelling adults in Japan. METHODS AND ANALYSIS: This study will be a two-arm, parallel-group RCT. We will recruit community-dwelling adults who are physically inactive in a suburban area (Nakayama) of Sendai city, Japan, using leaflets and posters. Participants that meet the inclusion criteria will be randomly allocated to an intervention group or a waitlist control group. The intervention group will be offered a financial incentive (a chance to get shopping points) if participants increase their daily steps from their baseline. The primary outcome will be the average increase in the number of daily steps (at 4–6 weeks and 7–9 weeks) relative to the average number of daily steps at the baseline (1–3 weeks). For the sample size calculation, we assumed that the difference of primary outcome would be 1302 steps. ETHICS AND DISSEMINATION: This study has been ethically approved by the research ethics committee of Tohoku University Graduate School of Medicine, Japan (No. 2018-1-171). The results will be submitted and published in a peer-reviewed scientific journal. TRIAL REGISTRATION NUMBER: UMIN000033276; Pre-results.