Supplementary material: Exploration of the impact of anticipated regret in lottery-based incentives on engagement levels of low-SES vocational students in a health promotion context

Public health literature has shown that individuals with lower socioeconomic status (SES) are generally less physically active and adhere to poorer diets than higher SES individuals. To promote healthier lifestyles in lower SES populations, we hosted a digital health promotion program among first- and second-year, vocational students at a school in The Netherlands. Particularly, in a pilot we evaluated whether this target audience could be engaged with an mHealth application using lottery-based incentives that trigger feelings of anticipated regret. Especially, we have studied the social and interpersonal aspects of regret lotteries in a within-subject experimental design. Additionally, we have studied the impact of varying payout schedules in terms of timing and monetary value in a between-subject experimental design. Results from a sample of 36 students between 15 and 25 years of age provided initial insights into effective configuration of lottery-based incentives that trigger feelings of anticipated regret to promote healthier lifestyles among lower SES vocational students. Particularly, implementation of incentives that include social, interpersonal, and competitive aspects are promising to foster user engagement levels. Furthermore, it was found that varying payout schedules may further promote engagement levels, although optimal configurations have still to be determined.<br><br><b>List of files</b><br>`0-intervention-design.pdf` includes visualisations of the mHealth application.<br><br>`0-list-of-variables.pdf` includes an overview of different variables within the dataset.<br>`1a-intervention-data.csv` includes data that was recorded from the intervention mHealth tool.<br>`1b-survey-data.csv` includes data that was recorded form a post-test survey.