Accuracy of home blood glucose monitors using forearm blood samples: FreeStyle versus One Touch Ultra

The accuracy of two home blood glucose monitors using forearm blood samples was studied. Blood samples were obtained from adults by venipuncture and analyzed for glucose concentration. Within five minutes after venipuncture, peripheral blood glucose measurements were taken in duplicate with the FreeStyle and One Touch Ultra monitors by using the same forearm as used for venipuncture. Accuracy was assessed by comparing the results for each first peripheral stick obtained by each monitor with the laboratory reference value. Monitor precision was evaluated by evaluating the mean difference in glucose values between the first and second peripheral sticks. Blood samples were obtained from 250 subjects, 170 (68%) of whom had diabetes mellitus. A total of 98.8% and 98.4% of the blood glucose readings obtained with FreeStyle and One Touch Ultra, respectively, were clinically acceptable, and 65.2% and 59.2% of the measurements, respectively, were within 10% of the laboratory reference values. The average difference between the first and second glucose measurements was 9.7 mg/dL for FreeStyle and 5.2 mg/dL for One Touch Ultra. One peripheral stick was needed to obtain an adequate blood sample in 95.6% of subjects using FreeStyle, compared with 83.2% of subjects using One Touch Ultra. Forearm blood glucose measurements obtained with the FreeStyle and One Touch Ultra devices were similar to laboratory reference values obtained by venipuncture.