Correlation of fingerstick blood glucose measurements with GlucoWatch biographer glucose results in young subjects with type 1 diabetes.

OBJECTIVE: The purpose of this study was to compare measurements of glucose obtained via iontophoretic extraction with the GlucoWatch automatic glucose biographer (Cygnus, Inc., Redwood City, CA) with capillary blood glucose values that were determined 1) in a controlled outpatient clinic setting and 2) in a home setting. RESEARCH DESIGN AND METHODS: There were 76 GlucoWatch biographers used on 28 different young adults (21 women and 7 men) with type 1 diabetes (age 30.9 +/- 6.9 years and duration of diabetes 18.4 +/- 8.1 years [mean +/- SD]) in a controlled outpatient clinic setting. Some subjects participated on multiple days. Subjects wore two GlucoWatch biographers, each on the forearm (ventral aspect). Comparisons were made to HemoCue blood glucose analyzer (Aktiebolgat Leo, Helsingborg, Sweden) capillary blood glucose measurements. In addition, GlucoWatch biographers (one each day for 3 consecutive days) were used by 12 subjects (8 women, 4 men) in a home setting. Comparisons were made to capillary blood glucose values determined using the One Touch Profile meter (Johnson & Johnson, New Brunswick, NJ). RESULTS: GlucoWatch biographer glucose values correlated well with capillary blood glucose values determined using the HemoCue analyzer in the clinic setting (r = 0.90, 1,554 paired data points) and using the One Touch Profile meter in the home setting (r = 0.85, 204 paired data points). When 36 subjects wore two biographers simultaneously, the correlation between the two biographers was r = 0.94. The error grid analysis demonstrated that > 96% of biographer glucose values determined in the clinic or home setting were in the clinically acceptable A and B regions. CONCLUSIONS: This study confirms the accuracy and precision of glucose values as determined using the GlucoWatch biographer in clinic and home settings.