Glucose Meter Problems Reported to FDA

Reports from BG monitor users to FDA reveal the most common problems with blood glucose monitors.

Glucose meters have unquestionable clinical utility, particularly in management of diabetes mellitus. U.S. Food and Drug Administration (FDA) surveillance activities include monitoring adverse event reports from healthcare professionals, manufacturers, and lay users.

To gain insight into problems reported to FDA on glucose meters, the FDA analyzed reports received over a 3-year period (2000–2002) from all sources (mandatory and voluntary) and focused on reports from users.

The results showed that the vast majority of in vitro diagnostic device (IVD) reports (84%, n = 18,959) were on glucose meters, with 333 glucose meter reports from users. Among the user reports, the most common problems were false high or low values and erratic values. Unique issues reported included purchase of incorrect glucose meter strips, calibration problems, and misunderstanding how FDA regulates glucose device performance.

THE U.S. FOOD AND DRUG ADMINISTRATION (FDA) receives more adverse event reports on glucose meters than on any other in vitro diagnostic device (IVD). They studied adverse event reports on glucose meters received during the 3-year period from 2000 through 2002, giving special attention to voluntary reports submitted by device users through FDA’s Med.-Watch program (see description below). Most adverse event reports come to FDA from manufacturers as mandatory reports. FDA requires manufacturers to investigate device problems, to take any needed corrective actions, and to report their actions and conclusions to FDA. FDA analyses often focus on mandatory reports because they include the results of manufacturer investigations.

Given that approximately 4.2 million self-monitoring glucose test strips are used each day in the United States, users reported very few problems directly to FDA.

Most (53%) of the voluntary reports on glucose meters came from patients. By comparison, only 17% of reports on all IVD products came from patients. Others who submitted re-ports on glucose meters included patient family members, pharmacists, other healthcare providers, and (in one case) an attorney.

Among the voluntary reports, the most commonly reported glucose meter problems were false high values (n = 17), false low values (n = 15), and erratic values (n = 11). In addition, reports identified a number of unique issues:

*Six users reported they had inadvertently purchased meter strips labeled not for use in the United States. These strips often exhibited differences in calibration, labeling, and expiration dating. Users should be advised to check their glucose strip labeling and promptly return any inappropriately imported strips.

• Two users did not know the two ways to calibrate glucose meters to measure finger stick glucose are to match finger stick glucose results with: (1) glucose results in whole blood and (2) glucose results in plasma. Both ways produce clinically valuable results; however, the results differ in that plasma results are 10–12% higher than whole blood results. Users should carefully read all labels and instructions for use for their meter and their glucose test strips to determine how their meter is calibrated, and to understand how calibration affects their treatment decisions.

• Some users expressed surprise that FDA does not have performance requirements for glucose meters. The Medical Device Amendments of 1976 require new tests to be as accurate as old tests. The Diabetes Control and Complications Trial unequivocally indicated home glucose measurements are valuable.

* Data suggest the current generation of glucose meters performs better than those used in that study. An absolute measure of accuracy for glucose has not been defined. Because no universally recognized glucose reference method exists, it is difficult to compare the performance of glucose meters.

Recently, FDA worked with scientists across the globe to develop a new standard for glucose meters that sets a target of 20% total error and requires labeling to help communicate meter performance.

• Some reports indicated users did not know how to check glucose meter performance. Users should know they can compare their meter results with the result of a laboratory test ordered by their physician.

Additionally, users should know that manufacturers of glucose meters will provide them:

• technical support
• quality control materials they can use to check or monitor meter performance
• replacement strips, meters, and calibration check materials

MedWatch is the FDA Safety Information and Adverse Event Reporting Program, is FDA’s established mechanism for healthcare professionals and others to voluntarily report problems suspected to be associated with drugs and medical devices they prescribe, dispense, or use. MedWatch also provides information about safety issues involving medical products, including prescription and over-the-counter drugs, biologics, medical and radiation-emitting devices, and special nutritional products. Medical product safety alerts, recalls, withdrawals, and important labeling changes are disseminated to the medical community and the general public on the MedWatch web site at: https://w-vvw.fda.gov/medwatch/index.htiid.
FDA encourages those who use glucose meters to report problems to MedWatch. Reports can be submitted as follows:

Fax to 1-800-FDA-0178, Phone to 1-800-FDA-1088, submit online at: www.fda.gov/medwatch or mail to MedWatch, FDA, HF-2, 5600 Fishers Lane, Rockville, MD 20852-9787

REFERENCES
1. The U.S. blood glucose strips market: diabetes glucose self-monitoring test strips market: annual utilization of test strips 2002. Dialog File Number 767. Accession Number 1022839. London: Frost and Sullivan. Available from: https://www.dialogselect.com/business/ cgi/present. Accessed 09 June 2003.
2. Weitgasser R, Gappmayer B, Pichler M: Newer portable glucose meters—analytical improvement compared with previous generation devices? Clin Chem 1999;45:1821-1825.
3. International Standardization Organization: ISO/FDIS 15197:2003(E). Requirements for In Vitro Blood Glucose Monitoring Systems for Self-Testing in Managing Diabetes Mellitus. U.S. Technical Advisory Group for ISO/TC212. Administered by NCCLS. Wayne, PA: Global Consensus
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