Bolus Insulin Dose Error Distributions Based on Results From Two Clinical Trials Comparing Blood Glucose Monitoring Systems.

BACKGROUND

In 2 previous clinical trials, fingertip capillary blood samples were evaluated using prespecified blood glucose monitoring systems (BGMSs) and a reference YSI glucose analyzer. In post hoc analyses, hypothetical insulin doses were calculated using these blood glucose measurements; dosing errors were compared for each trial.

METHOD

For each blood glucose measurement, premeal bolus insulin dosing was determined for a hypothetical person, assuming a 60-g carbohydrate meal and 100-mg/dL target blood glucose level (adjusting 1/25 insulin sensitivity and 1/15 insulin:carbohydrate ratio inputs to account for BGMS measurement error). Dosing error was the difference between doses calculated using the BGMS and YSI results.

RESULTS

In Clinical Trial 1, 95% dose error ranges (in units of insulin) were: CONTOURNEXT EZ BGMS (EZ), -0.9 to 0.5; Accu-Chek Aviva BGMS (ACA), -0.5 to 1.8; FreeStyle Freedom Lite BGMS (FFL), -3.2 to -0.3; OneTouch Ultra2 BGMS (OTU2), -4.1 to 0.3; and Truetrack BGMS (TT), -3.9 to 2.2. In Clinical Trial 2, these ranges were: CONTOURNEXT BGMS (CN), -0.7 to 1.7; Accu-Chek Aviva Nano BGMS (ACAN), -1.3 to 1.8; FreeStyle Lite BGMS (FSL), -5.1 to 0.2; OTU2, -1.9 to 1.2; OneTouch Verio Pro BGMS (OTVP), -1.0 to 1.9; and TT, -5.1 to 1.7. Within each trial, EZ and CN had statistically significantly smaller insulin dose error ranges than other BGMSs ( P <0.0001).

CONCLUSIONS

The ranges of insulin dose errors were statistically significantly smaller with EZ and CN than with all other BGMSs in this post hoc analysis. Differences in BGMS accuracy could result in clinically important differences in insulin dosing.