Accuracy of self-monitoring of blood glucose: Impact on diabetes management decisions during pregnancy

Purpose This study tested the hypothesis that the accuracy of self-monitoring of bl ood glucose (SMBG) values of patients with diabetes during pregnancy deviat es substantially from reference values. Methods The patients' glucose values were measured on 6 different SMBG meters; refe rence values were from the HemoCue B Glucose Analyzer. Over a 5-year period , 1973 comparisons between SMBG; values and reference values were recorded curing clinic visits and used for this study. Data were analyzed for percen t of values that varied more than +/- 10.5% and +/- 15.5% from the referenc e value. Out-of-range data at each variance level were analyzed to determin e the impact on medical management if decisions were based solely on SMBG v alues. Results One third of SMBG readings deviated significantly, which could adversely af fect treatment for half of these patients if diabetes management was based on SMBG values. At the 10.5% deviation level, 34% of SMBG meter readings we re out of range; 54% of these would have implied erroneous treatment. At th e 15.5% deviation level, 18% were out of range; 63% of these would have imp lied erroneous management. Conclusions The accuracy of home meters should be verified at regular intervals, and SM BG values should not be the sole criterion for diabetes management during p regnancy.