The purpose of the study is to evaluate, prospectively, the potential impact of different email message conditions (no email, standard promotional email, social norms, and loss framing) on enrollment in a wellness program (myHealth Rewards) by Geisinger Health Plan (GHP) members.

The myHealth Rewards wellness program managed by GHP rewards those GHP members who carry their insurance through employment at Geisinger with reduced health insurance premiums over the course of the following year, if members register for the program and have their health measures on file by the enrollment deadline and are then able to meet their health goals by the respective due date. In spite of the potential savings to health plan members and the wellness program's potential to motivate engagement in healthy activities (with consequent improvement in health outcomes), over 20% of eligible GHP members have not yet enrolled in 2019, even after receiving promotional email communications and reminders. Therefore, the current study was developed to test whether different versions of emails are more effective than a standard reminder email or no-email condition in increasing myHealth Rewards login and enrollment rates. The standard email reminder mentions the average premium savings, the ease of the registration process, and the deadline for registering and having health measures on file, plus it provides links for registering and finding free health screenings where health measures can be collected and registered at one convenient time and location. The social norms email notes that a majority (78%) of GHP members' colleagues had enrolled in 2018, it provides a testimonial from a medical director at Geisinger's Commonwealth School of Medicine, stating the ways in which myHealth Rewards helped that doctor personally, and it emphasizes the simplicity and ease of taking the first step toward enrollment. The loss framing email suggests that GHP members are currently "throwing away" a precise monetary amount in savings by not participating and that they can therefore avoid missing out on substantial gains (i.e., savings) by taking action. It is hypothesized that, on average, each of the emails will increase enrollment compared with no email. Among GHP members who never enrolled in the past, it is hypothesized that the standard email reminder will not be as effective as the social norms and loss framing emails. Therefore, email conditions will be compared separately among those who did and did not register in 2018. Findings will help inform how best to increase enrollment in a wellness program among health plan members who have already received past promotional communications and who may or may not have participated in the past.

Inclusion Criteria:

• Geisinger employees who are benefits subscribers

Exclusion Criteria:

• Those who had already registered for myHealth Rewards in 2019, up through May 6, 2019
• New Geisinger employees hired between December 1, 2018 and May 6, 2019
• Existing Geisinger employees who transitioned from non-subscribers in 2018 to subscribers in 2019

The population consists of Geisinger Health Plan members who are benefits subscribers.

Data with no personally identifiable information will be made available to other researchers on the Open Science Framework for transparency. This will include the essential data and code needed to replicate the analysis that yielded reported findings. The PI did not examine or analyze any data from this study prior to this registration.

The data will become available after publication of study results in a scientific journal and will be available as long as the Open Science Framework hosts the data.

The data on the Open Science Framework will be open to anyone requesting that information.

The baseline outcome measure was not applicable, since enrollment and login in response to the email was the outcome. There was no previous email, and participants were selected for not having enrolled in the year of the study period.

No adverse events were evaluated.

We only received aggregate information about email engagement with no individual-level information collected (including those for adverse events).

For this study, we only received data about engagement with the email. Individual patients were not identified and demographic information such as age, sex, or gender were not collected.