Abstract
Purpose :
Longer diabetes mellitus (DM) duration and higher hemoglobin A1c (HbA1c) contribute to increased rates and severity of diabetic retinopathy (DR), but studies on the association between DR and socioeconomic status (SES) are still emerging. We performed a retrospective cohort study to analyze the prevalence, severity and risk factors of DR across SES with the proxy of Medicaid insurance versus other insurance.
Methods :
Inclusion criteria were patients aged 18-89 with Type 2 DM (determined by ICD 9 & 10 codes) from 1/1/2015 to 12/31/2020 seen at the Northwestern ophthalmology clinic. Endpoints were DR presence (defined by non-proliferative DR (NPDR) or proliferative DR (PDR)), severity of DR and HbA1c after initial visit. Bivariate statistics compared the prevalence and severity of DR in Medicaid patients versus other insurance using the χ2 significance test and compared the mean HbA1c in Medicaid patients versus other insurance using a t-test. Multivariate logistic regression calculated odds ratios of DR and HbA1c while controlling for age, gender, race and insurance.
Results :
6364 patients met inclusion criteria. The prevalence of DR amongst patients with Medicaid was higher than patients with other insurance (25.82% vs. 17.61%; p<0.0001) (Figure 1). At the initial visit, PDR prevalence in patients with Medicaid was higher than in patients with other insurance (5.93% vs. 3.36%; p=0.0001). Mean HbA1c in Medicaid patients was greater than patients with other insurance (7.73 vs. 7.44; p<0.0001).
Medicaid was associated with a 53.9% increased DR risk compared to other insurance. A 1-unit increase in HbA1c posed a 32.0% increased DR risk, and male gender posed a 15.2% increased DR risk compared to female gender (Figure 2).
Conclusions :
Increased DM duration and poorer glycemic control are established DR risk factors. This study determined that Medicaid is a significant third risk factor. Of these three, Medicaid is often easiest to identify when a health system analyzes its data to find those in most need of screening. DM duration is often unknown or not documented in a way that is easily measured, and HbA1c varies over time.
90% of vision loss from DR is preventable if detected early. This study suggests patients with Medicaid should be considered as an additional high-risk group for DR screening programs.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.