The systematic shortcomings of opportunistic screening for diabetic retinopathy

Background: Diabetic retinopathy (DR) is a leading cause of vision loss among working age adults, with early detection and regular screening being critical for prevention. In Austria, DR screening is conducted opportunistically, lacking the systematic approach seen in other countries. This study evaluates the uptake of DR screening, the impact of a diabetes-specific Disease Management Program (DMP), and the potential for systemic regional screening to address gaps. Method: We conducted a retrospective cohort study to investigate diabetic screening be havior using pseudonymized administrative data from the Austrian Health Insurance Fund in Upper Austria (AHIF-UA), encompassing 1,439,900 total observations. To isolate the effects of diabetes diagnosis on eye screening participation, we employed a quasi-experimental design that controls for unobserved heterogeneity by comparing individuals with similar diagnosis dates. To determine the causal effect of access to timing of the diabetes diagnosis and DMP enrollment, our study exploits the quasi-random assignment of primary care providers (PCPs) to practices and patients. Findings: Results indicate a statistically significant 5 percentage-point increase in eye care visits right after a diabetes diagnosis. However, overall adherence was low: only 46% of individuals had an ophthalmology visit in the first year, and 16.7% maintained annual visits over three years. Enrollment in the DMP significantly improved screening rates. Patients assigned to a PCP offering the DMP were twice as likely to enroll, demonstrating access as the primary driver. Interpretation: The study highlights the limitations of opportunistic screening, with significant disparities in access and adherence. Opportunistic screening for DR in Upper Austria fails to ensure adequate coverage, leaving many individuals at risk of preventable vision loss. While DMP enrollment improves adherence to screening guidelines, the overall impact is limited. The findings underscore the need for systematic screening programs to address disparities and improve outcomes. Funding: None.