Relative Inaccuracy of the A1cNow in Children With Type 1 Diabetes

  1. Larry Fox, MD1,
  2. Mariya Dontchev, MPH2,
  3. Katrina Ruedy, MSPH2,
  4. Roy Beck, MD, PHD2,
  5. Craig Kollman, PHD2,
  6. Laurel Messer, RN3,
  7. Julie Coffey, MSN4,
  8. Darrell Wilson, MD5,
  9. Elizabeth Doyle, MSN6,
  10. William Tamborlane, MD6,
  11. Michael Steffes, MD, PHD7 and
  12. The DirecNet Study Group
  1. 1Nemours Children’s Clinic, Jacksonville, Florida
  2. 2Jaeb Center for Health Research, Tampa, Florida
  3. 3Barbara Davis Center, Denver, Colorado
  4. 4University of Iowa, Iowa City, Iowa
  5. 5Stanford University, Stanford, California
  6. 6Yale University, New Haven, Connecticut
  7. 7University of Minnesota, Minneapolis, Minnesota
  1. Address correspondence and reprint requests to Larry Fox, MD c/o DirecNet Coordinating Center, Jaeb Center for Health Research, 15310 Amberly Dr., Suite 350, Tampa, FL 33647. E-mail: direcnet{at}jaeb.org

The Diabetes Control and Complications Trial (DCCT) confirmed the importance of tight glucose control in limiting the development of microvascular complications and established a standard for measuring A1C levels using high-performance liquid chromatography (HPLC) (1). Several studies demonstrated the benefit of rapid A1C testing in the clinic while face-to-face with the patient/family (2–4). The DCA2000 Analyzer (Bayer, Tarrytown, NY) uses an immunoassay method certified by the National Glycohemoglobin Standardization Program (NGSP) (5). It is frequently used to provide a rapid (6 min) A1C result, enhancing the ability to optimize therapy in a timely fashion. We recently reported that the DCA2000 was highly correlated with an HPLC reference (the DCCT standard) (r = 0.94, P < 0.001), although there was a slight bias with DCA2000 values being, on average, 0.2% higher than laboratory values (6).

The A1cNow (Metrika, Sunnyvale, CA) was developed as a single-use, disposable test for measuring A1C at home. It is small, about the size of a pager, requires one drop of blood, and uses an immunoassay. Results are displayed in ∼8 min. However, there has been only one published study (7) to date assessing …

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