Abstract
BACKGROUND: For methods that report quantitatively, an assessment of their imprecision and bias should be assessed in the laboratory before their deployment into routine service. This study assessed these parameters of the HbA1C method on the STANDARD F2400® point of care analyzer. These parameters were further combined to generate sigma metrics for the method. METHODOLOGY: An external quality assurance (EQA) material from the Randox International Quality Assessment Scheme (RIQAS) was analysed according to the EP15 protocol of the Clinical Laboratory Standards Institute in SYNLAB Nigeria Laboratory Quality Assurance Department. Estimates of precision and an assessment of bias were determined from the data which consisted of 5 replicates per day for 5 consecutive days. Precision estimates were compared with manufacturer-provided information and estimates of bias were compared with the verification interval for the target value provided by RIQAS. Sigma metrics were determined for total allowable error (TAE) of 8% and 10%. RESULTS: The grand mean (standard deviation) for the study was 4.95 (0.15) %. The Within-run CV and within laboratory CV were 1.28% and 1.86%, respectively. These were within the manufacturer claims of 1.70% and 1.90%, also respectively. The target value by RIQAS was 5.04(0.24) % with a calculated verification interval of 4.95 - 5.13%. The sigma metrics for the method at TAE of 8% and 10% were 4.8/3.3 and 6.3/4.3 within the run/within laboratory estimates respectively. CONCLUSION: The HbA1C method on the STANDARD F2400® Analyzer displayed performance characteristics that are consistent with manufacturer specifications and are above industry standard quality for a point-of-care device for HbA1C. These suggest that may be used to support routine monitoring of persons with diabetes mellitus in Nigeria.