Validation and feasibility of a postal system for remote monitoring of HbA1c

Introduction The COVID-19 pandemic has reduced the accessibility to hemoglobin A1c (HbA1c) tests required for virtual diabetes clinics. The aim was to develop and validate a user-friendly postal system for remote HbA1c monitoring. Research design and methods Validation: A total of 123 capillary blood samples from people with diabetes (PWD) needing face-to-face consultations along with healthy volunteers were measured on a point-of-care (POC) Siemens DCA Vantage Analyzer. Another sample of 5-10 drops was simultaneously collected in a K2EDTA tube (BD Microtainer) and stored for up to 12 days at room temperature for subsequent retesting. Feasibility: During October to December 2020, a total of 286 postal HbA1c kits were sent to PWD prior to their virtual consultation. These contained sample collection guidance, the necessary equipment and a feedback form. As per Packing Instruction 650 regulations, these were posted back to the diabetes center for HbA1c testing on the POC analyzer. Results There was a strong correlation between the first and the stored sample (R-2=0.978). There was a small clinically insignificant negative bias -1.53 mmol/mol (2 SD = 3.10 mmol/mol). Bland-Altman plots showed 93% of results within 2 SD. Of the 87% of returned kits, only one sample failed to be analyzed. 94% of PWD who provided feedback were happy to use the postal HbA1c system again. Conclusions A robust user-friendly postal HbA1c system has been created and successfully integrated into clinical practice using the existing POC equipment at the diabetes center. It provides accurate HbA1c results and is an invaluable tool for remote monitoring of HbA1c in PWD-both during and after the pandemic.