Ronda F Greaves1, Jo-Ann T Northfield, Fergus J Cameron. 1. Division of Laboratory Services, The Royal Children's Hospital, Flemington Rd, Parkville, Victoria 3052, Australia. ronda.greaves@wch.org.au
Abstract
BACKGROUND: The measurement of haemoglobin A1c(HbA1c) by high-performance liquid chromatography (HPLC) is generally deemed unsuitable for point of care testing (POCT) due to its complexity and extended turnaround times (TAT). The aim of this project was to evaluate two new HPLC instruments, the Bio-Rad D10 and the Primus PDQ, as POCT instruments compared with Bayer's DCA2000 HbA1c immunoassay analyser in our paediatric diabetes clinic. METHODS: A total of 228 samples were analysed, of which 160 analyses were performed in our paediatric diabetes clinic. HbA1c results were compared by the Passing-Bablok agreement test, the Bland-Altman difference analysis, within- and between-run imprecision, and TAT. RESULTS: : The agreement test and difference analysis showed a correlation of r2 = 0.96 and a mean HbA1c difference of < 0.1% between the three analysers. The PDQ and the D10 achieved the within-run target coefficient of variation (CV) of < 2% at an HbA1c of 7.5%. Between-run imprecision at an HbA1c of 10.8% produced CV of 3.5%, 2.4% and 1.6% for the D10, DCA2000 and PDQ, respectively. TAT studies confirmed that the PDQ was substantially faster than the DCA2000 and D10. CONCLUSIONS: The PDQ had the shortest TAT, afforded random access and exhibited acceptable imprecision, and hence is the preferred instrument for our POCT environment.
BACKGROUND: The measurement of haemoglobin A1c(HbA1c) by high-performance liquid chromatography (HPLC) is generally deemed unsuitable for point of care testing (POCT) due to its complexity and extended turnaround times (TAT). The aim of this project was to evaluate two new HPLC instruments, the Bio-Rad D10 and the Primus PDQ, as POCT instruments compared with Bayer's DCA2000 HbA1c immunoassay analyser in our paediatric diabetes clinic. METHODS: A total of 228 samples were analysed, of which 160 analyses were performed in our paediatric diabetes clinic. HbA1c results were compared by the Passing-Bablok agreement test, the Bland-Altman difference analysis, within- and between-run imprecision, and TAT. RESULTS: : The agreement test and difference analysis showed a correlation of r2 = 0.96 and a mean HbA1c difference of < 0.1% between the three analysers. The PDQ and the D10 achieved the within-run target coefficient of variation (CV) of < 2% at an HbA1c of 7.5%. Between-run imprecision at an HbA1c of 10.8% produced CV of 3.5%, 2.4% and 1.6% for the D10, DCA2000 and PDQ, respectively. TAT studies confirmed that the PDQ was substantially faster than the DCA2000 and D10. CONCLUSIONS: The PDQ had the shortest TAT, afforded random access and exhibited acceptable imprecision, and hence is the preferred instrument for our POCT environment.