Postal methods for monitoring HbA1c in diabetes mellitus: A protocol for systematic review.

ABSTRACT

BACKGROUND: Worldwide there are an estimated 463 million people with diabetes. In the UK people with diabetes are offered annual review which includes monitoring of Haemoglobin A1c (HbA1c). This can identify people with diabetes who are not meeting their glycaemic targets, enabling early intervention. Those who do not attend these reviews often have poorer health outcomes. During the Coronavirus disease 2019 (COVID-19) pandemic, there was a 77% reduction in monitoring of HbA1c in the UK. AIM: We hypothesise that people with diabetes could take finger-prick samples at home for measurement of HbA1c. We will examine the agreement and correlation of capillary HbA1c values compared to a venous reference standard. We will explore reliability and repeatability of capillary HbA1c testing methods. We will explore the direction of effect of storage variables. We will also explore patient acceptability and safety. We will look at capillary blood methods which would be suitable for posting. METHOD: Using core terms of 'Diabetes', 'HbA1c' and 'Capillary sampling' we will search MEDLINE, Embase, CINAHL, Web of Science Core Collection, Google Scholar, Open Grey, and other grey literature from database inception until 2021. Risk of bias will be assessed using the 'COSMIN risk of bias tool to assess the quality of studies on reliability and measurement error'. CONCLUSION: We will produce a narrative synthesis to explore whether there are viable postal alternatives to venous sampling as well as exploring acceptability and safety of patient self-collection. PROSPERO REGISTRATION NUMBER CRD42021225606.