Evaluation of the Quo-Test Hemoglobin A1c Point-of-Care Instrument: Second Chance

We previously reported the evaluation of 8 different hemoglobin A1c (Hb A1c)1 point-of-care instruments (1). Two of 8 manufacturers withdrew from that study after initial unpromising results. One of the 2 instruments withdrawn was the Quo-Test A1c (Quotient Diagnostics), which was withdrawn because of a technical problem. The manufacturer claimed to have resolved the problem and asked us to reevaluate the instrument. The Quo-Test method is based on affinity separation and the use of fluorescence quenching and gives results in 3 min. The instrument was certified by the National Gycohemoglobin Standardization Program (NGSP) as of September 2009 (2). We used the same approach for evaluation as in the initial study, following the CLSI EP-5 protocol for imprecision and the CLSI EP-9 protocol for method comparison. Because the American Diabetes Association has recommended Hb A1c as the preferred test for the diagnosis of diabetes (3), we added an additional sample of approximately 6.5% Hb A1c in the EP-5 protocol. The EP-9 protocol was performed twice with 2 different lot numbers and compared with 3 IFCC and NGSP secondary reference measurement procedures (SRM): the Roche Tina-quant Hemoglobin A1c Gen.2 on Cobas Integra …