Data indicate that diabetic retinopathy is the leading cause of new-onset, irreversible blindness in US adults younger than 75. Although screening is essential for early detection of diabetic retinopathy, and current treatments have been shown to be highly effective in preventing severe vision loss, evidence suggests that patient adherence to annual eye exams, as recommended by the American Academy of Ophthalmology (AAO), is poor. Prior studies, which have suggested adherence rates ranging from 23% to 65%, are limited to specific patient populations. For a study published in Ophthalmology, my colleagues and I were the first to examine adherence rates and how they differ by demographic using a nationally representative sample.
The study was a cross-sectional secondary analysis using the National Health and Nutrition Examination Survey (NHANES) survey data from 2005 to 2016, which includes retinal photography. We selected participants aged 20 or older with a patient-reported diagnosis of diabetes, and we used univariate and multivariate logistic regression to determine characteristics associated with adherence to annual eye exams. Because NHANES uses a complex weighting scheme to produce estimates representative of the non-institutionalized civilian US population, our sample of 4,072 participants represents more than 20 million adults in the US with diabetes. The total study population adherence rate for an annual eye exam was 63%. Although the proportion of participants with self-reported diabetes increased from 7.8% to 11.4% over the study period, there was no significant change in adherence rates, suggesting that a greater number of patients with diabetes did not receive annual eye exams. The populations least likely to have had an eye exam in the past year were younger, uninsured, low-income, and had a more recent diagnosis of diabetes. Individuals who denied receiving a diagnosis of diabetic retinopathy also had lower adherence rates. Insurance status carried the highest predictive value for adherence, with adherence among uninsured individuals found to be only 36%, compared with 76% for those with dual public-private insurance (Figure). These findings are likely unsurprising to most clinicians, as lack of health insurance is a well-known major barrier to all types of care, especially preventative medicine and screening.
On the topic of diabetes education, participants had a poor understanding of whether they may have diabetic retinopathy. A surprising 70% of patients with evidence of retinopathy on exam denied having a diagnosis of retinopathy, and incorrect denials were twice as common as incorrect endorsements. Put plainly, most patients who had evidence of retinopathy on exam were unaware of their diagnosis. Interestingly, there was no significant association between correctly reporting one’s retinopathy status and being adherent to the annual eye exam. Patients are evidently confused about diabetic eye disease screening, the diagnosis of retinopathy, and their own eye health. Every healthcare professional who interacts with such patients can play an integral role in helping their patients better understand their complex disease and empowering them to have an active role in preventing sequelae.
In addition to improved patient education, large-scale initiatives are likely required in order to improve adherence rates to annual eye exams among patients with diabetes. The implementation of retinal photography at primary care clinics, especially targeting vulnerable populations and those with the lowest adherence rates, may improve adherence by increasing accessibility and convenience, though further study is needed. With improved awareness of the patient populations that are at greatest risk of non-adherence to annual diabetic eye exams, providers and clinics can target certain patients who will benefit from additional support and education regarding diabetic retinopathy screening in order to reduce the burden of preventable blindness.