Variability among five over-the-counter blood glucose monitors.
BACKGROUND
The American Diabetes Association recommends that people with diabetes use self-monitoring to control their blood glucose concentration. To assess the need for standardization, we evaluated the variability among 5 of the most common monitors: MediSense Precision Xtra, Ascencia Dex, Prestige Smart System, OneTouch Ultra, and Accu-Chek Advantage.


METHODS
We took steps to minimize preanalytical variation. We also eliminated user variability by using one trained operator to collect samples and perform all testing. Each monitor was used twice with each participant; one test was performed using an aged strip and the other using a fresh strip. We compared monitors using a separate ANOVA for each concentration range and strip lot.


RESULTS
The total CVs and the within-strip lot CVs were not statistically different among monitors, ranging from 3.1% to 11.3% and from 2.1% to 8.5%, respectively. There were statistically significant differences among monitors for among-strip lot CVs, which ranged from nearly 0% to 7.5%. The degree of significance increased as the concentration range increased [3.9-5.5 mmol/l: p<0.05; 5.6-7.7 mmol/l: p =0.003; 7.8-11.1 mmol/l: p < 0.001]. The average percent difference between monitor pairs was statistically significant (p < 0.05) in more than half of the paired comparisons, with significant differences ranging from 5.7% to 32.0%.


CONCLUSIONS
Monitor results can vary significantly so that agreement among them is poor. Standardization is necessary to minimize variability and to improve patient care.
Kimberly
Mary M
MM
Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Mailstop F25, 4770 Buford Hwy NE, Atlanta, GA 30341-3724, USA. mkimberly@cdc.gov
Vesper
Hubert W
HW
Caudill
Samuel P
SP
Ethridge
Steven F
SF
Archibold
Enada
E
Porter
Kimberly H
KH
Myers
Gary L
GL
D000328:Adult; D000465:Algorithms; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000592:standards; D003920:Diabetes Mellitus / Q000097:blood* / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods / Q000592:standards; D012015:Reference Standards; D012016:Reference Values; D015203:Reproducibility of Results
D001786:Blood Glucose