The Cost-Effectiveness of Screening for Type 2 Diabetes

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The summary below is from the full report titled "Screening for Type 2 Diabetes Mellitus: A Cost-Effectiveness Analysis." It is in the 4 May 2004 issue of Annals of Internal Medicine (volume 140, pages 689-699). The authors are T.J. Hoerger, R. Harris, K.A. Hicks, K. Donahue, S. Sorensen, and M. Engelgau.

What is the problem and what is known about it so far?

Diabetes interferes with the body's ability to store energy from food. The pancreas makes a substance called insulin, which helps store energy from food. Type 1 diabetes (juvenile diabetes) occurs when the pancreas stops making insulin. In type 2 diabetes (adult-onset diabetes), the body makes enough insulin but cannot use it normally. In both cases, the result is high blood sugar levels. Over time, high blood sugar levels can lead to blindness, kidney failure, nerve damage, and heart disease. Fortunately, good care with diet; exercise; and medications to control blood sugar, blood pressure, and cholesterol levels helps to prevent these complications. Type 1 diabetes is usually diagnosed promptly. However, many people with type 2 diabetes have the disorder for years before symptoms begin. Testing people who have no symptoms to try to detect disease early is called screening. In 2003, the U.S. Preventive Services Task Force recommended that adults who have high blood pressure or cholesterol levels should be screened for type 2 diabetes. The economic implications of these recommendations are unknown.

Why did the researchers do this particular study?

To estimate whether the cost of type 2 diabetes screening is worth the potential benefits.

Who was studied?

Rather than studying actual patients, the researchers used computers to simulate what would happen to a "virtual" group of adult primary care patients.

How was the study done?

The researchers used published information to estimate what might happen (and how much it would cost) if doctors screened all adults for type 2 diabetes. They also estimated what might happen (and how much it would cost) if doctors screened only patients with high blood pressure. They put these estimates into the computer model and calculated how much each strategy would cost per year of life that it saved.

What did the researchers find?

The researchers found that screening people with high blood pressure for type 2 diabetes was much more cost-effective than screening all adult patients. Costs for screening people with high blood pressure who were 55 to 75 years old were well within the range that American society is typically willing to pay for health care treatments. For example, screening a 55-year-old person with high blood pressure costs about $34,375 per year of life saved. Screening all adults, regardless of whether they have high blood pressure or not, costs more than $300,000 more per year of life saved—much more than Americans are typically willing to pay.

What were the limitations of the study?

The study was a computer simulation, so we cannot be sure what the results would be with actual patients. In addition, the recommendations consider cholesterol levels, but this cost model did not.

What are the implications of the study?

The cost-effectiveness of screening persons 55 to 75 years of age with high blood pressure seems to be well within the range that American society is typically willing to pay for health care treatments.