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Few Point-of-Care Hemoglobin A_1c Assay Methods Meet Clinical Needs

¹ Department of Pathology, University of Virginia Medical School and Health System, Charlottesville, VA.

^aAddress correspondence to this author at: Department of Pathology, P.O. Box 800168, University of Virginia Medical School and Health System, Charlottesville, VA 22908. E-mail jcb7h@virginia.edu.

The first 300 words of the full text of this article appear below.

Accurate and timely measurements of hemoglobin A_1c (Hb A_1c)¹ are an increasingly important challenge for clinical laboratories. As Hb A_1c measurements are being used to answer new clinical questions, each new use of Hb A_1c imposes requirements for the analytical performance of the methods used to measure it. Until recently, Hb A_1c was used only as a key test for monitoring glycemic control in people with diabetes. More recently, it has been proposed as the preferred test for the diagnosis of diabetes (1)(2), and it is being used in many areas to calculate an estimated average glucose (eAG) concentration (3)(4).

The analytical requirements differ in these 3 uses of the test. In monitoring glycemic control, as with any test used for monitoring therapy, the reproducibility of Hb A_1c assays is critical. Freedom from bias, however, has also become critical, because fixed cutpoints are being used as targets for glycemic control. When Hb A_1c is used for measuring eAG concentrations, errors in the measurement may produce unexpectedly large changes in eAG. In the diagnosis of diabetes, fixed cutpoints are used, again requiring particular attention to the effect of bias on diagnostic accuracy. In addition to analytical requirements, there is pressure for rapid return of results in view of evidence that improved glycemic control can be achieved when Hb A_1c results are made available at the point of care (POC) (5)(6). It is against this background that an important new report addresses the analytical performance of POC assays for Hb A_1c.

In this issue of Clinical Chemistry, Lenters-Westra and Slingerland (7) report on the imprecision, bias, and total error of 8 POC Hb A_1c analyzers. The study used well-defined protocols from the CLSI and 3 . . . [Full Text of this Article]

Hb A_1c in Monitoring of Glycemic Control and Calculation of eAG

Hb A_1c in the Diagnosis of Diabetes

Are Current Quality Specifications for Hb A_1c Measurement Adequate to Meet Clinical Needs?

The following articles in journals at HighWire Press have cited this article:

				B. Irvin, J. Knaebel, and D. Simmons Assessing the Performance of Point-of-Care Hemoglobin A1c Systems Clin. Chem., August 1, 2010; 56(8): 1359 - 1360. [Full Text] [PDF]

				E. Lenters-Westra and R. J. Slingerland In Reply Clin. Chem., August 1, 2010; 56(8): 1360 - 1361. [Full Text] [PDF]

				E. Lenters-Westra and R. J. Slingerland Evaluation of the Quo-Test Hemoglobin A1c Point-of-Care Instrument: Second Chance Clin. Chem., July 1, 2010; 56(7): 1191 - 1193. [Full Text] [PDF]