Triennial Diabetes Screening Cost Effective

Routine screening for diabetes type 2 every three years in older Americans could be conducted at acceptable cost using a random plasma glucose cut point of 130 mg/dL. Lead author Dr. Susan L. Johnson stated that, “Screening people 45 years of age or older every three years with a blood glucose test is appropriate and affordable. “Ideally, such screening should occur as a part of ongoing medical care.”

Dr. Johnson of the University of Michigan Health System, Ann Arbor, and colleagues note that the direct and indirect cost of diabetes in the US in 2002 was estimated to be $132 billion.

Because of this enormous cost and the relative ease with which type 2 diabetes can be detected in its preclinical stage, the American Diabetes Association has recommended screening in asymptomatic people of 45 years and older.

To estimate the cost of certain screening strategies for monitoring the US population, the researchers simulated screening with random plasma glucose (RPG) measurement and cut points of 100, 130 and 160 mg/dL. They also evaluated a multivariate equation using RPG and other variables.

The subjects were projected to be from 45 to 74 years of ages and to have been screened at intervals of 1, 2 and 3 years. Positive results were assumed to prompt a definitive diagnostic test such as fasting plasma glucose.

Over a 15-year period, the absolute difference between the most sensitive and most specific screening strategies was 4.5 million true positives and 476 million false positives. The cost of the most sensitive screening was $42.7 billion and that of the most specific was $6.9 billion.

The best compromise, the researchers calculated, was 3-yearly use of an RPG with a cut point of 130 mg/dL, or use of the multivariate equation. The cost using the 130-mg/dL cutoff was $11.1 billion versus $9.7 billion for the equation.

If testing were done during routine check ups, the cost of detecting one undiagnosed case of diabetes would be just $275.
“Approximately 5.2 million Americans have undiagnosed diabetes,” Dr. Johnson added, and such screening, the researchers conclude, “provides a good yield and minimizes false-positive screening tests and costs.”
Diabetes Care 2005;28:307-311.