Large-Scale Fandom-based Gamification Intervention to Increase Physical Activity: A Quasi-experimental Study.

PURPOSE Gamification, the use of game design elements in nongame contexts, in combination with insights from behavioral economics has been applied increasingly to behavior change interventions. However, little is known about the effectiveness or scalability of this approach, especially in the long term. We tested a large-scale smartphone-based intervention to encourage physical activity among Japanese baseball fans using gamification techniques that leveraged fandom and inter-team competition inherent in sports. METHODS A quasi-experimental study was conducted among fans of the Japanese Pacific League. The app, Pa-League Walk, included gamification elements, such as competition between opposing teams' fans based on total daily step counts on game days (>60,000 free downloads since March 2016). We analyzed daily steps of 20,052 app users, supplemented by online survey data of 274 users and 613 matched controls. Difference-in-differences estimators evaluated change in daily steps before and after app installation in users versus matched controls. RESULTS Users' daily steps increased by 574 (95% confidence interval: 83, 1064) steps three months after installation, compared to controls. The increase was maintained for up to nine months (559 [99, 1018] more steps per day versus baseline), attenuating over a longer follow-up. Positive effect modification was found by high frequency of the app use (P < 0.001) but not by other covariables (P ≥ 0.14) such as education or income. Days with 10,000 steps achievement increased from 24.4% to 27.5% after the additional introduction of incentives (digital player photos) (P < 0.001). CONCLUSION Using existing fandom and solidarity, the gamification app increased physical activity at scale among baseball fans, including people with lower socioeconomic status under-represented in traditional health programs.