The purpose of the research is to test the effectiveness of different messaging approaches to nudge members of Vitality and Discovery Health, with risk factors for diabetes (based on data from the Vitality Health Check and Vitality Age assessment), to visit a doctor and test for diabetes. The messages are based on concepts from behavioural economics that aim to make information on screening more salient by using the concept of social proof (person like you) and an authoritative source (a diabetes specialist and the Vitality doctor).

Members of Vitality who are also members of the Discovery Health medical plan and who have risk factors for diabetes but who have not previously been diagnosed with diabetes will be eligible for the study. Subjects will be identified based on the Vitality Age assessment and the Vitality Health Check done in the previous year. The risk factors identified by these assessments and which are important for eligibility are age ≥45years, overweight and obesity, family history of diabetes, hypertension or raised high blood pressure, low levels of physical activity, cardiovascular disease, and dyslipidemia. It is estimated that approximately 5000 Vitality members will be eligible for the study. Only the actuarial team assigned to the study will have access to the data. Participants will de-identified and randomly allocated to the control and four intervention arms. Messages will be sent via email to them which addresses their specific health risks and measures they can take to address those risk. The messages will be in an encrypted PDF sent by email. In compliance with the POPIA Act, as a first step, participants will be asked to provide consent, by confirming their ID number, to share their individual risks information with them. Messages sent via email will have the same basic structure. All three of the experimental arm messages will include the following:

• The same subject line
• A description of their risk factors for diabetes
• A description of the benefits of visiting a doctor and getting screened for diabetes

Inclusion Criteria:

• Members of Vitality who are also members of the Discovery Health medical plan and who have risk factors for diabetes but who have not previously been diagnosed with diabetes
• Risk factors are age ≥45years, overweight and obesity, family history of diabetes, hypertension or raised high blood pressure, low levels of physical activity, cardiovascular disease, and dyslipidemia.

Exclusion Criteria:

• < 18 years >= 65 years
• Diagnosed with diabetes