Mailed letter versus phone call to increase diabetic retinopathy screening engagement by patients in a team-based primary care practice: a prospective, single-masked, randomized trial. (Preprint)

BACKGROUND Vision loss from diabetic retinopathy (DR) is preventable through regular screening. OBJECTIVE The purpose of this study was to test different patient engagement approaches to expand a teleophthalmology program at a primary care clinic in the city of Toronto, Canada. METHODS A teleophthalmology program was set up in a large urban academic team-based primary care practice. Patients over 18 years of age, with type 1 or type 2 diabetes were randomized to one of four engagement strategies: a phone call, a letter, a letter plus phone call, or usual care. Outreach was conducted by administrative staff within the clinic. The primary outcome was booking an appointment RESULTS Twenty three patients in the phone, 28 in the mail, 32 in the mail and phone, and 27 in the control (usual care) were included in the analysis. After the intervention, 88% of patients in the phone, 11% in the mail, and 100% in the mail and phone group booked an appointment with the teleophthalmology program compared to 0% in the control group. Phoning patients positively predicted patients booking a teleophthalmology appointment (p< .0001), while sending a letter had no effect. CONCLUSIONS Patient engagement to book DR screening via teleophthalmology in an urban academic team-based primary care practice using telephone calls was much more effective than letters or usual care. Practices that have access to a local DR screening programs and have resources for such engagement strategies should consider using them as a means in improving their DR screening rates.