Is opt-out enrolment acceptable for low-risk digital health services?

Introduction Digital health programmes not only complement existing services, but have the potential to reach populations that existing services are not reaching. Many of these services require people to opt-in to receive them, which presents significant barriers to access. An alternative is to make low-risk digital services opt-out, ensuring appropriate members of the target audience are signed up for a service unless they select to not receive it. Aim This study aimed to investigate how changing enrolment in a low-risk digital health programme from opt-in to opt-out would impact on enrolment and dropout rates. Methods This study involved the retrospective analysis of registration data from txtpēpi, a maternal and child health text-message programme. System-recorded data from enrolments during a 12-month period were obtained. In the first 6 months, users had to opt-in to the service (Period 1), but in the following 6 months, an opt-out process was implemented (Period 2). Results There was a 77% increase in enrolments in Period 2 (n  = 113) compared to Period 1 (n  = 64) and no significant change in the proportion of enrolments of Māori between time periods (P  = 0.508). There was no significant difference in withdrawal rates between time periods at either 2 weeks (5% vs 6%, P  = 0.676) or 1 month (9% vs 9%, P  = 0.907). Discussion This study has shown switching from an opt-in to an opt-out option resulted in an increase in enrolments in an mHealth programme, but had no impact on withdrawals. This indicates that employing opt-out enrolment for low-risk evidence-based interventions is acceptable and a potential way to make these services more accessible.