New Type of Analysis Reveals Clinically Relevant Inaccuracies Missed by Other Methods

WHAT: Keeping hospitalized patients’ glucose concentrations within a defined set of parameters, often referred to as “tight glycemic control,” significantly improves patient outcomes. Consequently, many hospitals have implemented glycemic control programs that use point-of-care (POC) glucose meters to monitor patients’ glucose levels. Unfortunately, ensuring accuracy can be problematic with some POC glucose meters, but University of California-Davis researcher Gerald Kost, MD, PhD, says that POC testing “does not represent an excuse for inaccuracy.” He has invented a new method of measuring glucose meter performance that can help hospitals identify devices that are giving inaccurate results. Asserting that it’s time to “raise the bar” for performance of POC glucose meters, Kost proposes that hospitals and manufacturers use Locally Smoothed Median Absolute Difference (LS-MAD) curves to assess glucose meter accuracy. “The method involves transforming discrete median absolute difference points in the x-y plane into a continuous curve that helps reveal underlying patterns between paired measurements obtained with a new POC instrument and a reference method,” says Kost. Curves within the “accuracy envelope” near therapeutic targets (e.g., 80 to 110 mg/dL) suggest that the glucose meter’s performance is adequate for bedside decision making in a tight glycemic control program. The method was recently tested at 35 sites during a U.S. multicenter study of a new glucose meter, and Kost was pleased with the results. With the LS-MAD method, all errors count, he says, and meter “signatures” will reveal clinically relevant inaccurate glucose ranges in instances where other methods may suggest nearly perfect agreement. Kost recommends that performance standards for bedside glucose testing in hospital settings adopt LS-MAD curves and an error tolerance of ≤ 5 mg/dL. The new method could also be used to evaluate other POC devices, said Kost, although different performance standards would have to be developed for each test. Kost will describe the new method and the results of the multicenter study at a seminar titled “Practical Applications for Point-of-Care Testing Programs: Glucose Control and Patient Safety.”

WHEN: Thursday, July 19, 2006, 9:30 A.M.-Noon

WHO: Gerald J. Kost, MD, PhD, Point-of-Care Testing Center for Teaching and Research, Pathology and Laboratory Medicine, School of Medicine, University of California, Davis, CA

WHERE: Room 6E of the San Diego Convention Center, at the Annual Meeting of the American Association for Clinical Chemistry (AACC). AACC’s members develop and perform tests conducted in hospital laboratories, clinics, medical centers and other health care settings. For more information on AACC, visit www.aacc.org

Interviews with Dr. Kost may be arranged on site or by telephone.