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.