Costs of screening for pre-diabetes among US adults: a comparison of different screening strategies.

OBJECTIVE

We evaluated various strategies to identify individuals aged 45-74 years with pre-diabetes (either impaired glucose tolerance or impaired fasting glucose).

RESEARCH DESIGN AND METHODS

We conducted a cost analysis to evaluate the effectiveness (proportion of cases identified), total costs, and efficiency (cost per case identified) of five detection strategies: an oral glucose tolerance test (OGTT), a fasting plasma glucose (FPG) test, an HbA(1c) test, a capillary blood glucose (CBG) test, and a risk assessment questionnaire. For the first strategy, all individuals received an OGTT. For the last four strategies, only those with a positive screening test received an OGTT. Data were from the Third U.S. National Health and Nutrition Examination Survey, 2000 census, Medicare, and published literature. One-time screening costs were estimated from both a single-payer perspective and a societal perspective.

RESULTS

The proportion of pre-diabetes and undiagnosed diabetes identified ranged from 69% to 100% (12.1-17.5 million). The cost per case identified ranged from US dollars 176 to US dollars 236 from a single-payer perspective and from US dollars 247 to US dollars 332 from a societal perspective. Testing all with OGTT was the most effective strategy, but the CBG test and risk assessment questionnaire were the most efficient. If people are substantially less willing to take an OGTT than a FPG test, then the FPG testing strategy was the most effective strategy.

CONCLUSIONS

There is a tradeoff between effectiveness and efficiency in choosing a strategy. The most favorable strategy depends on if the goal of the screening program is to identify more cases or to pursue the lowest cost per case. The expected percentage of the population willing to take an OGTT is also a consideration.