Search

OBJECTIVE—To determine whether clinically significant differences exist in fasting blood glucose (BG) at the forearm, palm, and thigh relative to the fingertip; to assess the impact of prandial status by comparing BG between alternative sites and the fingertip at several time intervals after carbohydrate intake; to assess the effects of moderate brief exercise on site-to-site differences in BG; to evaluate the impact of site preparation by local rubbing on alternative-site testing (AST) equivalence; and to determine levels of perceived pain and satisfaction associated with AST. RESEARCH DESIGN AND METHODS—Fasting BG was measured using the One Touch Ultra (LifeScan, Milpitas, CA) at the fingertip, palm, thigh, and each forearm (with local rubbing) in 86 patients with type 2 diabetes. A 40-g carbohydrate meal was consumed and BG was again measured from each site at 60, 90, and 120 min postmeal, with an additional forearm test at 90 min without local rubbing. Patients then exercised for 15 min with repeat BG at each site. Differences in BG between sites were assessed using repeated-measures ANOVA and regression analyses. RESULTS—Significant differences in BG at alternative sites were found 60 min postmeal (P = 0.0003) and postexercise (P = 0.037). Specifically, clinically significant differences (expressed as percent difference from the fingertip) at 60 min include −8.8 ± 10.8% at the forearm and −13.7 ± 10.7% at the thigh, and postexercise +19.1 ± 19.1% at the forearm and +15.6 ± 22.6% at the thigh. However, no significant differences were observed between sites in either the fasting state or at 90 and 120 min postmeal. The dynamic results suggest a time lag in equilibration of forearm and thigh BG during periods of rapid glucose change. Palm and fingertip BG test results were similar at all time points. CONCLUSIONS—AST results are consistent with fingertip BG results in both the fasting state and 2 h postmeal; no benefit from site preparation by local rubbing was noted. However, testing at sites other than the hand cannot be recommended 1 h postmeal or immediately after exercise. AST is equivalent and appropriate for use at testing times commonly used in clinical practice.

We assayed 100 capillary whole blood specimens from 50 adults on the Precision QID blood glucose testing system (MediSense, Waltham, Mass) and in duplicate on a whole blood reference method. We centrifuged aliquots of each specimen and analyzed the resulting plasma in the clinical laboratory. The Precision QID achieved maximum total error of 15.5% at a glucose concentration of 42 mg/dL, 12.3% at 83 mg/dL, and 6.4% at 280 mg/dL. The amount of error demonstrated satisfies the performance requirement established by the 1986 Conference on Self-Monitoring of Blood Gluco

In this article we examine the statistics that summarize random error (imprecision) and systematic error (inaccuracy) in the evaluation of blood glucose—monitoring devices. Random error is estimated from replicate testing of patient samples or manufacturers’ controls; systematic error is estimated from the comparison of methods study. Total error combines the measurements of random error and systematic error into a single value and allows comparison of glucose meters’ performance to established standards. Recommendations from the American Diabetes Association Consensus Conference in 1986 specify a 15% maximum performance error. These recommendations are standards currently accepted for evaluations of blood glucose meters.

Well-designed evaluations of blood glucose meters are fundamental to determining the acceptability of meters. Unfortunately, no standard guide exists to evaluate these meters. In this article we outline the meter evaluation process from establishing objectives to generating final recommendations with results that are statistically significant. Proper planning and execution of an evaluation can mitigate or even eliminate problems associated with glycolysis, hematocrit, and blood collection, and thus permit valid inter study comparison.

PURPOSEthis study was conducted to evaluate patients' proficiency in self-monitoring of blood glucose (SMBG).METHODSDiabetes nurse educators in 4 suburban Minneapolis clinic sites surveyed the SMBG training/cure practices of 280 patients with type 1 and type 2 diabetes. Participant SMBG technique was measured by direct observation. Participants performed a finger puncture and used their own meters to measure the first blood sample. A second sample was measured on the HemoCue B Glucose analyzer, and a third sample was used to measure hemoglobin. The series of tests were then repeated. If either of the 2 glucose tests was more than 15% from the HemoCue value, participants were reeducated about the manufacturer's suggested procedure.RESULTSOf the 280 participants, 19% had blood glucose test results greater than the 15% limit for meter accuracy. After reeducation, 69% of those who had initially failed achieved acceptable results. The most significant problems were lack of periodic meter technique evaluation, difficulty using wipe meters, incorrect use of control solutions, lack of hand washing even when observed, and unclean meters.CONCLUSIONSAs a result of the study, guidelines were subsequently developed to evaluate meter accuracy in an outpatient setting. Further effort is needed to establish standards for evaluating SMBG.