Estimating the microvascular benefits of screening for type 2 diabetes mellitus

To define the relative benefits of screening for diabetes and improved treatment programs and ways of improving the efficiency of screening for a population-based cohort derived from the Third National Health and Nutrition Examination Survey (NHANES III).

A Markov decision model is used to estimate microvascular benefits of glucose control for four different screening and treatment scenarios, including either universal screening or improved glucose control of known diabetic subjects, neither, or both.

A population cohort of subjects with recent onset of diabetes (< 5 years) was derived from NHANES III (of whom close to half were unaware that they had diabetes). In this population-based cohort, the total benefit achievable by universal screening and improved treatment (limiting HbA1c to less than 9%) is a reduction of about 30,000 cases of blindness over the lifetime of the cohort. Screening alone results in 7% of this benefit, and improved treatment alone provides 65%. Screening a targeted group of patients with three or more risk factors for developing diabetes would reduce the number of required fasting glucose measurements needed by 82% and provide 50% of the total benefit of screening the entire population with a fasting glucose measurement.

Morbidity from type 2 diabetes can be most effectively reduced by developing ways to modestly improve the glycemic control of known diabetic subjects, particularly those with high A1c's and early onset of disease. Targeting can significantly reduce the number of persons who need to be screened with a fasting blood test while preserving a large component of the benefit of screening.