Diabetes Care, Vol 15, Issue 8 1045-1049, Copyright © 1992 by American Diabetes Association
Immediate HbA1c results. Performance of new HbA1c system in pediatric outpatient population
DG Marrero, JL Vandagriff, R Gibson, SE Fineberg, NS Fineberg, CE Hiar and LE Crowley
Regenstrief Institute, Indianapolis, Indiana 46202.
OBJECTIVE--This study compared the performance of a new device that uses an
IA to measure HbA1c in 9 min with a 1-microliter capillary blood sample
with AC and CE methods in both nondiabetic and diabetic pediatric patients.
RESEARCH DESIGN AND METHODS--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.
RESULTS--Correlations and regression analyses show excellent correspondence
between the three assays. The correlation between the AC and CE methods is
0.98 (P less than 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
less than 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 less than
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 less than 0.001), reflecting the differences in
GHb components measured. There was a significant correlation (P less than
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%. CONCLUSIONS--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.