Longitudinal population-based analysis of diabetic retinopathy screening rates for newly diagnosed diabetes in Ontario

Objective — To evaluate longitudinal trends and determinants of diabetic retinopathy (DR) screening uptake over 10 years among adults with newly diagnosed diabetes in Ontario, Canada.

Methods — A population-based cohort study using linked ICES (formerly the Institute for Clinical Evaluative Sciences) administrative data, including adults aged ≥19 years with newly diagnosed diabetes between April 1, 2011, and March 31, 2020. The primary outcome was DR screening within 2 years of diagnosis. Predictors included age, sex, socioeconomic status, comorbidities, rurality, immigration status, and health system factors. Logistic regression evaluated the associations. Five-year rates and ocular complications were assessed.

Results — Among 691,557 individuals, 396,073 (57.3%) received DR screening within 2 years of diagnosis. Screening was more common among older adults, females, and individuals with higher comorbidity or rural residence, and less common among younger patients (OR [odds ratio]: 0.22 for age 20–39 vs ≥65; p < 0.0001), males (OR: 1.10 for females vs males; p < 0.0001), immigrants (OR: 0.98; p < 0.0001), and those in the lowest income quintile. One-year rates declined from 44.9% (2011/12) to 35.2% (2019/20), and 5-year rates from 76.8% (2011/12) to 72.4% (2017/18). DR and other ocular conditions were more often diagnosed among screened individuals. Screening dropped sharply during COVID-19, especially among younger adults.

Conclusions — Despite universal health care, substantial disparities in DR screening persist across age, sex, immigration status, and socioeconomic strata. Screening rates declined over time and were further exacerbated by COVID-19. These findings underscore the urgent need for targeted, equity-oriented strategies, such as teleophthalmology and primary care integration, to improve uptake and prevent vision loss in the growing diabetic population.