A new test kit, GTT@home, uses finger-prick blood samples to perform a standard OGTT procedure and record test data for cloud-based analysis. The procedure is self-administered conveniently at home. Data captured by the disposable GTT@home device can be sent by smartphone to the cloud for analysis, with results available electronically for interpretation. Performance of GTT@home was compared to corresponding venous plasma samples measured by the YSI 2300 reference analyser - the "gold standard" - for identification of glucose intolerance and diabetes.
100 women underwent a standard 2-hour OGTT procedure using a 75-gram glucose load. Corresponding finger prick and venous plasma samples were taken. Finger prick blood was added to the GTT@home device and venous plasma was analysed in the YSI analyser.
Compared to YSI venous plasma, sensitivity of GTT@home for glucose intolerance was 100% (fasting glucose) and 90% (2-hour glucose); for type 2 diabetes, 2-hour sensitivity was 93%. Specificity was 99%. There was a slight negative bias; fasting -1.4%, 2-hour -0.5%. Correlation to YSI was excellent, with combined (fasting and 2-hour values) R2 = 0.93 and kappa statistics of 0.96 (fasting) and 0.90 (2-hour).
GTT@home shows excellent correlation and low bias compared to laboratory YSI venous plasma, making it an effective replacement for laboratory based OGTT. Ease of use, patient acceptability increased test uptake have been demonstrated elsewhere. For detecting prediabetes and all forms of diabetes, GTT@home offers substantial improvements in sensitivity and specificity over the commonly used HbA1c test, with implications for the effectiveness of diabetes prevention programmes.