This study compared the performance of a new device that uses an IA to measure HbA1c in 9 min with a 1-μl capillary blood sample with AC and CE methods in both nondiabetic and diabetic pediatric patients.
Two hundred seven pediatric subjects (103 nondiabetic, 104 with insulin-dependent diabetes mellitus) had HbA1c measured with the IA method and compared with total GHb values determined by AC and HbA1 by the CE method with the same whole-blood capillary aliquot. Glucose values were also obtained from the same blood samples.
Correlations and regression analyses show excellent correspondence between the three assays. The correlation between the AC and CE methods is 0.98 (P < 0.001) with a slope of 1.615 ± 0.0125 and intercept of 4.00 ± 0.20. The correlation between the IA and AC methods is 0.99 (P < 0.001) with a slope of 0.608 ± 0.007 and intercept of 1.326 ± 0.066. The correlation between the IA and CE methods is 0.97 (P < 0.001), with a slope of 0.983 ± 0.018 and intercept of 1.122 ± 0.153. The average difference and average percentage difference between methods were also significant (P < 0.001), reflecting the differences in GHb components measured. There was a significant correlation (P < 0.001) between each method and glucose values (IA r = 0.72, AC r = 0.70, CE r = 0.73). Within-run precision for IA ranged from 1.7 to 3.5% and between-run precision 2.7 to 4.1%.
Study results suggest that the IA method gives extremely accurate and reliable values over the clinical range of interest. The instrument is small, portable, easy to use, and provides information within 9 min for both physicians and patients.