Using an A1C threshold of 5.7% for prediabetes is cost-effective, but the cost of treating patients at lower thresholds would probably outweigh the savings from better long-term outcomes, an analysis in the American Journal of Preventive Medicine found. Lowering the threshold by 0.1% increments from 6.4% to 5.5% correlated with improved health over a patient's lifetime, but thresholds lower than 5.7% exceeded $50,000 per quality life-year gained, the researchers said.

http://www.medpagetoday.com/Cardiology/Diabetes/31623