Cost-utility analysis of screening intervals for diabetic retinopathy in patients with type 2 diabetes mellitus

Context Annual eye screening for patients with diabetes mellitus is frequently proposed as a measure of quality of care. However, the benefit of annual vs less frequent screening intervals has not been well evaluated, especially for low-risk patients. Objective To examine the marginal cost-effectiveness of various screening intervals for eye disease in patients with type 2 diabetes, stratified by age and level of glycemic control. Design Markov cost-effectiveness model. Setting and Participants Hypothetical patients based on the US population of diabetic patients older than 40 years from the Third National Health and Nutrition Examination Survey. Main Outcome Measures Patient time spent blind, quality-adjusted life-years (QALYs), and costs of annual vs less frequent screening compared by age and level of hemoglobin A(1c). Results Retinal screening in patients with type 2 diabetes is an effective intervention; however, the risk reduction varies dramatically by age and level of glycemic control. On average, a high-risk patient who is aged 45 years and has a hemoglobin A(1c) level of 11% gains 21 days of sight when screened annually as opposed to every third year, while a low-risk patient who is aged 65 years and has a hemoglobin A(1c) level of 7% gains an average of 3 days of sight. The marginal cost-effectiveness of screening annually vs every other year also varies; patients in the high-risk group cost an additional $40 530 per QALY gained, while those in the low-risk group cost an additional $211 570 per QALY gained. In the US population, retinal screening annually vs every other year for patients with type 2 diabetes costs $107 510 per QALY gained, while screening every other year vs every third year costs $49 760 per QALY gained. Conclusions Annual retinal screening for all patients with type 2 diabetes without previously detected retinopathy may not be warranted on the basis of cost-effectiveness, and tailoring recommendations to individual circumstances may be preferable. Organizations evaluating quality of care should consider costs and benefits carefully before setting universal standards.