New research examines cost-effectiveness of lowering HbA1C cutoff

NEW YORK — Reducing the cutoff of hemoglobin A1C to determine if a patient has prediabetes could be cost effective, according to a new study.

The American Diabetes Association recommends HbA1C testing as one basis for identifying diabetes and prediabetes and has established the HbA1C value of 6.5% as the diagnostic cutoff. Researchers — led by Xiaohui Zhuo of the Division of Diabetes Translation at the National Center for Chronic Disease Prevention and Health Promotion of the Centers for Disease Control and Prevention — sought to determine "the cost effectiveness associated with the alternative HbA1C cutoffs for identifying prediabetes." The researchers created a simulation sample from data of nondiabetic American adults, ages 18 years and older, from the National Health and Nutritional Examination Survey (1999-2006).

Lowering the HbA1C cutoff would increase the health benefits of the preventive interventions at higher costs:

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  For high-cost intervention, lowering the HbA1C cutoff from 6% to 5.9% and from 5.9% to 5.8% would result in $27,000 and $34,000 per quality-adjusted life-year gained, respectively;

  
  


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  Decreasing the cutoff from 5.8% to 5.7%, from 5.7% to 5.6% and from 5.6% to 5.5% would cost $45,000, $58,000, and $96,000 per QALY gained, respectively;

  
  


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  For the low-cost intervention, lowering the HbA1C cutoff from 6% to 5.9% and from 5.9% to 5.8% would result in $24,000 and $27,000 per QALY gained, respectively;

  
  


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  Lowering the cutoff from 5.8% to 5.7%, 5.7% to 5.6%, and 5.6% to 5.5% would cost $34,000, $43,000 and $70,000 per QALY gained, respectively.

  
  

"Establishing an HbA1C cutoff for prediabetes ... has been more challenging than for diabetes because the relationship between the incidence of Type 2 diabetes and HbA1C below 6.5% is continuous, with no clearly demarcated threshold that is associated with an accelerated risk of diabetes or other morbidities," the study authors said. "It was found that lowering the HbA1C cutoff resulted in greater health benefıts, but also led to an increase in costs and, consequently, a decrease in the economic effıciency of preventive interventions. As a result, from a healthcare system perspective, determination of an optimal HbA1C cutoff ultimately depends on the level of effıciency that society can accept, or more specifıcally, the resources it is willing to make available for Type 2 diabetes prevention."

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