Nudging Handwashing among Primary School Students in the Philippines: Evidence from a Cluster Randomized Trial.

Handwashing is key to preventing the transmission of various infectious diseases of which school-aged children are particularly susceptible. Traditional, information-messaging campaigns may increase handwashing awareness but have had limited success in promoting behavior change. Behavioral economics "nudges," which explicitly target the knowledge-behavior gap, is a promising alternative. We evaluate the impact of school-based nudges in the first fully powered cluster randomized controlled trial in the Philippines. Out of our sample of 132 eligible schools, we randomly assigned half to receive nudges, including contextual cues (painted footpath from toilet to handwashing station) and visible reminders (posters and eye sticker), and half to the control group. Four months after implementation, we measured handwashing with soap (HWWS) after toilet use among grades 1-6 students using direct observation and compared this outcome between treatment and control schools. We also assessed whether nudges increased soap availability. The intervention increased HWWS rates by 17.3% points (pp), [95% CI: 4.2, 30.4] in treatment schools from the control group mean of 11.7%. The effect size was comparable across gender and age groups. Access to functioning handwashing facilities with soap increased by 36% (+20.2 pp, 95% CI: 10.9, 29.4). Mediation analysis suggests the program simultaneously nudged students to wash hands with soap in classrooms that already had soap, and nudged teachers to provide soap where it was not already available. These findings demonstrate that behavioral nudges costing less than $70 per school can lead to significant increases in HWWS among students 4 months post-intervention.

Can Social Motivators Improve Handwashing Behavior among Children? Evidence from a Cluster Randomized Trial of a School Hygiene Intervention in the Philippines.

This study reports the impact of the HiFive program, a 6-week handwashing campaign that targets social and emotional motivators to improve student handwashing in primary schools in the Philippines. We designed a clustered randomized trial to evaluate the impact of HiFive on student handwashing behavior, motivation, and access. Of the sample of 196 primary schools located in two districts, half were randomly assigned to receive the program in the 2017-2018 school year. Survey and observation data were collected 3 months after the conclusion of the campaign. In control schools, only 2.5% of students were observed washing their hands with soap and water, our primary outcome and 14.8% were observed washing their hands with at least water. HiFive led to a 3.7 percentage point (p.p.) increase (P < 0.01) in the rate of handwashing with soap and water and a 5.6 p.p. increase (P = 0.03) in handwashing with at least water after toilet use. HiFive also led to a 10.8 p.p. (P < 0.01) increase in the number of handwashing facilities stocked with soap. The program had limited impact on the motivators targeted by the program, suggesting that the small improvements in handwashing may have been driven by increases in the availability of soap. More research is needed to understand how interventions can effectively trigger social motivators to improve handwashing behavior among schoolchildren, and whether the effectiveness of these programs can be augmented with "nudge"-based interventions from the behavioral sciences.