Abstract
Purpose :
Total diabetic screening (DR) incidence is rarely reported by national screening programmes. We evaluate the cumulative DR screening incidence in a Danish regional cohort and calculate HR based on sex, diabetes type and screening location, and validate screening visits at hospitals.
Methods :
We analysed ten years of longitudinal data from 2009-2018 from the Danish National Prescription Registry, Health Service Registry and Patient Registry. DR screening is free. Patients with diabetes (type 1 and 2 (T1D/T2D)) living in the North Denmark Region in 2009 were included. Females age <40 who only received Metformin were discarded due to the possibility of receiving treatment for polycystic ovarian syndrome or endometriosis. Patients who died or moved were censored. A high-quality local database was used to cross-validate DR screening visits at hospitals. Cumulative incidence curves and cause-specific HRs were calculated using SAS.
Results :
Of 580,515 inhabitants by 1st Jan 2009, 18,832 individuals had diabetes (43.9% females. 13.4% T1D) and were included. At the end of the 9th year, 93.9% (95% CI: 93.4 – 94.3) of patients with T1D and T2D had been screened for DR. Females (T1D & T2D) had a HR at 1.084 (95% CI: 1.051-1.119; p<.0001). T1D had a HR at 1.157 (95% CI: 1.100-1.217; p<.0001). Screening at hospitals had a HR of 1.573 (95% CI: 1.510–1.639; p<.0001). The screening proportion trend rose (p<.0001) from 60.2% (95% CI: 59.5–60.9) (2009: 11,330/18,832) to 69.3% (95% CI: 68.5–70.1) (2018: 8,653/12,489) of the eligible population. The mean positive predictive value (PPV) for hospital screening visits compared to the high-quality database was 86.78% (95% CI: 86.76–86.81).
Conclusions :
Overall a high screening incidence with a significant increasing trend was found. T1D screened at hospitals and females were the most likely categories to be screened, whereas males with T2D screened at private ophthalmologists were the least screened group. The mean PPV for hospital screening visits was high compared to the high-quality local database. Most other studies, to the best of our knowledge, only report screening attendance for patients already enrolled in a DR screening programme, our study describes the overall screening attendance for the total eligible diabetes population.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.