This site complies with the HONcode standard for trustworthy health information:
verify here.

Rewarding for
you and us
Defeat Diabetes Foundation

Defeat Diabetes
Foundation
150 153rd Ave,
Suite 300
Madeira Beach, FL 33708

Patients Miscode Monitors 16% of the Time Causing Faulty Readings

Posted: Thursday, November 16, 2006

Significant Errors In Insulin Dose Can Result When Blood Glucose Meters Are Miscoded According to New Clinical Study

When persons with diabetes use miscoded blood glucose meters to determine how much insulin to take, significant errors in insulin dose can result that may potentially lead to short- and long-term health complications, according to findings of a new study presented at the Sixth Annual Diabetes Technology Meeting in Atlanta, Georgia.

In this study, for certain miscoded meters, the probability of insulin error of plus or minus 2 units of insulin was 50% as compared to 8% for correctly, manually coded meters. The probability of insulin dose error of plus or minus 3 units of insulin was 23% for the miscoded meters but only 0.5% for the manually correctly coded meters.

Coding is the process by which a blood glucose meter is matched to each new box of test strips being used. This is done either by inserting a code strip or code chip into the meter, or by entering a code number into the meter. If this step is not performed, the meter may give inaccurate results leading to wrong therapy. For example, relying on a miscoded blood glucose meter to determine how much insulin to take can result in a potentially harmful overdose. Insulin overdose may cause dangerously low blood sugar (hypoglycemia) leading to behavioral changes, confusion, loss of consciousness and, if untreated, seizure, coma and even death. Chronic under-dosing of insulin may contribute to the long-term health problems associated with high blood sugar including kidney disease, nerve disease, eye problems, and heart disease.

"When dealing with patients with diabetes we've observed that many either do not understand what proper coding is, or do not realize its importance. Patients sometimes use expired test strips and/or fail to properly code their blood glucose meters to the lot of test strips they are using," said Dr. Steven Edelman, an author on the study and Professor of Medicine, division of Endocrinology and Metabolism, University of California, San Diego, and the Veterans Affairs Medical Center.

The study findings also showed that auto-coded meters (meters that automatically set the correct code anytime a test strip is inserted) gave more accurate blood glucose values than meters that had been correctly coded manually. This also translated into a lower probability of insulin dose error. For auto-coded meters, the probability of plus or minus 1 unit and plus or minus 2 units of insulin could be as high as 35.4% and 1.4% respectively. However, with the auto-coded meters, there were no calculated insulin dose errors above plus or minus 2 units.

"These findings are significant because studies have shown that approximately 16% - or one out of six - persons failed to properly manually code their blood glucose meters to the lot of test strips being used. The study authors concluded that to avoid insulin dosing errors, people should be carefully instructed how to correctly code their meters or be advised to use an auto-coded meter.

Glucose values obtained from some of the miscoded meters used for this study showed an average error ranging between plus 29% and minus 37%.

A Monte Carlo simulation, (a statistical method that uses existing data sets to forecast performance in the field) was conducted on the data from the clinical trial to generate 'ideal' and 'simulated-meter' glucose values, and subsequent insulin doses. This simulation was based on various assumptions such as, one unit (1U) of insulin covers 50mg/dL blood glucose.* From these calculations, the probability of insulin dose errors for the three types of blood glucose meters (miscoded, manually correctly coded and autocoded) were determined.

The probability for an error of plus or minus one unit of insulin was 44.6% for correctly coded meters compared to 49.6% for incorrectly coded meters. The probability for an error with a miscoded meter of plus or minus four units of insulin was 2.8% and for plus or minus five units of insulin was 0.06%. There was no instance of a plus or minus four or five unit error with correctly, manually coded meters. For auto-coded meters there were no calculated insulin dose errors above plus or minus two unit.

Source: Diabetes In Control: American Diabetes Association: www.diabetes.org/diabetes-statistics.jsp: Roper 2005 U.S. Diabetes Patient Marker Study, April 19, 2006 Raine, C.H. Endo Prac 9: pg 137, 2003