Fig. 4. (A) Illustration of the blood-collection device. (B) Collection of capillary blood samples with the device. (C) Photo of the device being used. Comparison of HbA1c measurements obtained from the commercialized “TAP” device and venepuncture (n = 243) using (D) Linear regression analysis and (E) Bland-Altman analysis (reproduced from ref. 81 with the permission of Nature, Copyright 2018).