This study aims to test the effectiveness of different types of incentives to motivate walking among people who use a tracker app. App users will be randomly allocated to three groups, Group 1 will received assured incentives in the form of points per minute of walking, Group 2 will received non-assured incentives in the form of prize draw tickets, one ticket per minute of walking and Group 3 will receive a combination of the two.

App-users will be invited to join the study and those who consent to joining will track their walking activity for 12 weeks using the BetterPoints app. Participants will also be asked to complete a survey at the start and end of the study period to assess motivation and responsiveness to reward.

At the end of the 12 weeks intervention period, changes in minutes of walking from the start of the study to three follow up time points will be assessed and compared between groups. Total minutes of walking will also be compared between groups. Differences in reported levels of autonomous motivation will be assessed between the start and end of the study and between groups.

It is well established that physical activity reduces risks of common noncommunicable diseases. It is predicted that 65 million people in the United Kingdom will use a smartphone by 2025. With such reach, mobile apps show promise as an intervention to promote physical activity. Although systematic reviews suggest that financial incentives are effective in encouraging physical activity, their cost effectiveness at population level is still unknown. Studies combining apps and incentives suggest that the size of the incentive is not as important as the type, timing and content, which has implications for the affordability of interventions.

Two types of incentive used in apps are assured rewards that are earned per step/minute of physical activity, and lottery incentives, where activity is rewarded with more entries to prize draws. Whether assured or won in a lottery, rewards are in the form of a digital currency that can then be redeemed for shopping vouchers or donated to charity.

The cost of giving out assured rewards is dependent upon the number of users and their level of activity. With lottery-based approaches, costs can be fixed. That is, the prize(s) in the lottery are fixed regardless of the number of users and their activity. However, this means the expected win per user per activity falls with more users and users being more active. The evidence comparing lottery-based incentives is limited. Patel and colleagues compared different lottery conditions over 13 weeks and found that a combined approach offering an 18% chance of winning $5 and 1% chance of winning $50, was more effective than a high frequency-low pay out or jackpot. No research could be found that directly compared lottery-based approaches with assured incentives. This is the gap which the current trial aims to fill.

The present study aims to assess the efficacy of an assured vs lottery vs combined incentive in fostering physical activity. Insights from the study could help develop scalable, cost-effective interventions to improve public health outcomes.

Inclusion Criteria:

Existing users of the BetterPoints app. Not in sponsored programmes.

Exclusion Criteria:

BetterPoints app users who are under 18. BetterPoints app users who are enrolled in programmes sponsored by local authorities.

No individual participant data will be available. Aggregated and anonymised data will be available upon reasonable request.

Participants will be randomly allocated to their group and will not be aware of the incentives received by the other groups. Randomisation will be done by team setting up the study in the BetterPoints system and the principle investigator will only receive anonymised data and be blind to who has been allocated to each group.