Use of point-of-care haemoglobin tests to diagnose childhood anaemia in low- and middle-income countries: A systematic review

Abstract

Objectives: Anaemia is a major cause of mortality and transfusion in children in low- and middle-income countries (LMICs); however, current diagnostics are slow, costly and frequently unavailable. Point-of-care haemoglobin tests (POC(Hb)Ts) could improve patient outcomes and use of resources by providing rapid and affordable results. We systematically reviewed the literature to investigate what, where and how POC(Hb)Ts are being used by health facilities in LMICs to diagnose childhood anaemia, and to explore challenges to their use.

Methods: We searched a total of nine databases and trial registries up to 10 June 2022 using the concepts: anaemia, POC(Hb)T, LMIC and clinical setting. Adults ≥21 years and literature published >15 years ago were excluded. A single reviewer conducted screening, data extraction and quality assessment (of diagnostic studies) using QUADAS-2. Outcomes including POC(Hb)T used, location, setting, challenges and diagnostic accuracy were synthesised.

Results: Of 626 records screened, 41 studies were included. Evidence is available on the use of 15 POC(Hb)Ts in hospitals (n = 28, 68%), health centres (n = 9, 22%) and clinics/units (n = 10, 24%) across 16 LMICs. HemoCue (HemoCue AB, Ängelholm, Sweden) was the most used test (n = 31, 76%). Key challenges reported were overestimation of haemoglobin concentration, clinically unacceptable limits of agreement, errors/difficulty in sampling, environmental factors, cost, inter-observer variability and supply of consumables. Five POC(Hb)Ts (33%) could not detect haemoglobin levels below 4.5 g/dL. Diagnostic accuracy varied, with sensitivity and specificity to detect anaemia ranging from 24.2% to 92.2% and 70% to 96.7%, respectively.

Conclusions: POC(Hb)Ts have been successfully utilised in health facilities in LMICs to diagnose childhood anaemia. However, limited evidence is available, and challenges exist that must be addressed before wider implementation. Further research is required to confirm accuracy, clinical benefits and cost-effectiveness.

Keywords: anaemia; children; haemoglobin; low- and middle-income countries; point-of-care testing; systematic review.

Figure 1. PRISMA 2020 Flow Diagram of Study Selection.

Four additional reports were identified for TRACT (n=2) and FEAST (n= 2) trials to give a total 45 reports and 41 included studies. Common reasons for exclusion due to wrong setting included at-home testing. Common reasons for exclusion due to not point-of-care haemoglobin test included use of laboratory analysers or other point-of-care tests for malaria and Sickle Cell Disease. n= number. WoS = Web of Science. CENTRAL = Cochrane Central Register of Controlled Trials. LILACS = Latin American and Caribbean Health Sciences Literature. ICTRP = International Clinical Trials Registry Platform. ProQuest = ProQuest Dissertations and Theses. POC = Point-of-care. Hb = Haemoglobin. LMIC = Low-and Middle-income Country.

Figure 2. Map Showing where POC Hb Tests have been used by Health Facilities in Children in LMICs.

Size of pie chart represents total number of tests and studies. Uganda (HemoCue n=7, I-STAT n=2, HCS n=1), Tanzania (HemoCue n=6, HCS n=2, Novel colour-based assay n=1), Nigeria (HemoCue n=2, Mission Hb n=2, HCS n=1), Ethiopia (HemoCue n=4), Kenya (HemoCue n=3, Hemo Control n=1), Gambia (HemoCue n=2, Aptus n=1), Cameroon (URIT-12 n=2, Mission Hb n=1), Malawi (HemoCue n=2, Hemo Spec n=1), Democratic Republic of Congo (HemoCue n=2), Ghana (HemoCue n=1, URIT-12 n=1), Rwanda (HemoCue n=1, Pronto n=1), India (HemoCue n=1, Rad-67 n=1), Mali (HemoCue n=1), Angola (Novel colour-based assay n=1), South Africa (HemoCue n=1) and Brazil (HemoCue n=1).