Capillary blood HbA1c testing enables rapid field screening but shows wide accuracy variability
The study reports a scoping review of 106 epidemiological studies evaluating capillary blood-based technologies for glycated hemoglobin measurement in adult populations. Investigators found that point-of-care devices dominate the landscape, requiring only 2 to 10 microliters of blood to deliver results within minutes, though reported diagnostic accuracy varies widely with sensitivities ranging from 17.4 to 100 percent and specificities from 43.5 to 99.1 percent. While dried blood spot approaches and portable analyzers support decentralized screening and remote sample collection, the review highlights substantial performance heterogeneity and a critical evidence gap, as seventy-seven percent of included research originates from high-income settings.
The original study
HbA1c measurement using capillary blood in epidemiological studies: a scoping review of technologies and approaches.
- Authors
- Breternitz BS, de Araújo RQ, Rother ET, de Andrade AB, de Freitas PC, Menezes-Júnior L, et al.
- Journal
- BMC endocrine disorders
- Type
- Journal Article, Systematic Review
- PMID
- 42436450
Original abstract
OBJECTIVE: To map and describe the capillary blood-based technologies employed to measure glycated hemoglobin (HbA1c) in epidemiological studies, focusing on their accuracy, applicability, feasibility, and implementation barriers. INTRODUCTION: The development of technologies for diabetes screening and monitoring has expanded, particularly in decentralized and epidemiological contexts. METHODS: A scoping review was conducted in accordance with PRISMA-ScR guidelines. A comprehensive literature search was performed in Embase, Scopus, Web of Science, LILACS, and CINAHL between 18 and 24 February 2025. The search was conducted without restrictions on language, publication year, or geographic location, retrieving studies indexed up to 31 January 2025. We included primary epidemiological studies involving adults (≥ 18 years) that assessed HbA1c measurement using capillary blood technologies or approaches in field or population-based settings. Studies exclusively evaluating capillary glucometers, continuous glucose monitoring, or oral glucose tolerance tests were excluded. Two reviewers independently screened records and assessed full-text eligibility against pre-specified criteria registered on the Open Science Framework (OSF). Data were extracted and synthesized descriptively based on outcomes reported by the original study authors and categorized in regard to the aim. RESULTS: Of 2,238 records screened, 106 studies were included. Fifteen distinct analytical technologies for HbA1c measurement using capillary blood were identified, with Point-of-Care Testing (PoCT) devices representing the predominant category. Among studies reporting diagnostic accuracy metrics, sensitivity ranged from 17.4% to 100% and specificity from 43.5% to 99.1%. PoCT devices required 2-10 µL of capillary blood and produced results within minutes. Applicability findings described portability, limited training requirements, and use in decentralized settings. Dried Blood Spot (DBS) approaches facilitated remote collection and mailing to reference laboratories. Reported challenges included variability in analytical performance, limited validation in Low- and Middle-Income Countries (LMICs), and operational constraints related to cost, supply logistics, and integration into health systems. Overall, 77% of included studies were conducted in High-Income Countries (HICs). CONCLUSIONS: Capillary blood-based technologies for HbA1c measurement have been applied across diverse epidemiological contexts, with reported analytical and operational characteristics consistent with decentralized use. Nevertheless, the evidence remains geographically concentrated and heterogeneous, indicating gaps in research from LMICs.