Patients diagnosed with diabetes who received guideline-recommended levels of care had substantially reduced levels of low vision or blindness over a 3-year period compared with similar individuals who did not receive such care, according to a large, retrospective, longitudinal cohort analysis.
This was true even though the incidence of background diabetic retinopathy (DR) was greater in the patients receiving recommended care. The increased incidence likely was the result of better diagnosis of the patients who had recommended care; they received more eye examinations than did their non-recommended counterparts, investigators reported in Ophthalmology.
“Better diabetes management, including stricter adherence by patients and doctors to best practice guidelines, could have an enormous protective impact on cases of vision loss caused by DR. More stringent testing would raise Medicare costs short term for both beneficiaries and the Medicare program, but may pay dividends long term both in medical costs incurred owing to the progression of DR, as well as improved quality of life,” wrote Frank A. Sloan, Ph.D., and his colleagues at Duke University, Durham, N.C.
The investigators obtained data from Medicare claims and the Medicare Current Beneficiary Survey (MCBS), a random sample of Medicare beneficiaries aged 65 or older. During the study period (1991-2004), approximately 12,500 beneficiaries were surveyed for the MCBS; 5,989 met the study criteria of having a diagnosis of diabetes and no evidence of background DR, proliferative DR, any complication of proliferative DR, or blindness/low vision, the researchers stated.
Receipt of recommended levels of care was determined by evidence of annual use of five categories of service: physician exam, ophthalmologist or optometrist exam, hemoglobin A1c test, lipid test, and urinalysis.
Analysis revealed that people who were younger and had a history of cataracts, insulin dependence, lipidemia, and a body mass index greater than 30 were more likely to receive recommended levels of care. An increase in household income of $10,000 also correlated with a greater likelihood of receiving recommended care. The authors postulated that patients with another health problem were more likely to be seen by physicians, and that younger persons were more likely to seek treatment.
Propensity analysis was used to match individuals in the population of patients not receiving recommended treatment with those individuals who did; this led to 849 pairs in the 2-month analysis and 119 pairs in the 3-year analysis. Differences in DR and vision were then compared (Ophthalmol. 2009;116:1515-21).
At 2, 3, and 6 months and at 1 and 2 years (but not at 3 years), patients in the recommended care group were significantly more likely to develop background DR than were those in the non–recommended care group. There were no differences in the appearance of PDR, PDR complications, or macular edema at any time period. The researchers postulated that patients with more frequent examinations were likelier to be diagnosed with the more subtle background DR than were those seen less often by a physician.
More importantly, persons receiving the recommended level of care had a significantly lower likelihood of developing vision loss or requiring a visual aid at 1, 2, and 3 years (a lowering of 0.016, 0.040, and 0.109, respectively), according to the researchers.
“To increase rates of receipt of recommended levels of care will require a multipronged strategy, including programs that stress the importance of these [eye] examinations and provide reminders to physicians to order all the recommended testing,” the researchers concluded.
The authors reported having no relevant conflicts of interest. The study was funded in part by the National Institute on Aging.