Anaemia Research and Measurement in Population Study
According to the WHO, about 42% of children under 5 years of age and 40% of pregnant women worldwide are anaemic. Anaemia is diagnosed by measuring haemoglobin (Hb) concentration in the blood and its prevalence is defined as the percent of people whose Hb concentration falls below a predetermined reference value. This value can be adjusted when necessary for local populations based on varying demographic factors which have been shown to influence haemoglobin concentration, like settlement/residence altitude and smoking status.
While Automated haematology analyzers are used to measure Hb concentration in a medical laboratory, Point of care (POC) devices like the HemoCue® are commonly used to measure Hb in household surveys due to their portability and ease of use in field settings as they can run on battery power in the absence of electric supply. They also have the advantage of using capillary blood obtained by a simple finger prick as against autoanalyzers which require venous blood.
However, various studies have reported varying results for Haemoglobin concentration using different equipment and method of sample collection. It has not been clearly determined if the discrepancies are from the mode of sample collection (capillary or venous), errors in the blood collection process or due to environmental factors like heat and humidity. This could have a substantial effect on the estimation of anaemia prevalence in populations as anaemia data is most commonly obtained from field surveys, especially in low and middle-income countries.
Along with research institutions from other continents; the American University of Beirut (Lebanon), Instituto Nutricional de Centroamérica y Panamá (Guatemala), the National Institute for Medical Research (Tanzania) and the University of British Columbia, EHA Clinics in collaboration with eHealth Africa embarked on a Haemoglobin Measurement (HEME) Laboratory Validation Study to identify the best procedures and methods for determining haemoglobin (Hb) concentration, and therefore the anaemia prevalence in population surveys.
The HEME Project was sponsored by USAID’s Advancing Nutrition Grants program and led by the JSI Research & Training Institute, Inc. (JSI) and a consortium of partners. The program focuses on improving nutritional status and health outcomes where the burden of malnutrition is highest and critically impacts on young children, their caregivers, and women of reproductive age (WRA).
A total of 108 volunteers comprising 54 Women of Reproductive Age (WRA) and 54 Children Under 5 years (grouped into 12-23 months and 24-59 months) were recruited and enrolled for the study based on set criteria and informed consent was obtained for each patient. The volunteers were sourced mainly from patient encounters within the Clinic and through Community engagements across various settlements in Abuja.
Demographic Data relating to factors influencing Hb measurement were collected using a digitised and secure HIPAA-compliant CAPI tool (REDCap) and assigned code numbers without the use of identifiers to ensure patient confidentiality. The participants were free to withdraw at any time without any potential negative consequences.
Capillary and Venous blood samples were obtained following CDC 2020 procedure for venous blood collection and ICF International 2012 procedure for single-drop sampling. This was done once and without a follow-up visit. The samples were analysed in EHA Clinics’ ISO-certified laboratory, Abuja and with SYNLAB, Abuja serving as a central reference laboratory.
While participants in the study enjoyed the benefit of Free Haemoglobin tests and received their auto-analyzer test results as well as interpretation, participation in the study attracted no direct compensation to ensure the authenticity of data collected and to prevent the enrollment of ineligible participants.
Based on result comparisons from all participating research institutions, findings from the HEME study will inform the use of standardised sampling procedures and appropriate field devices in population surveys, thereby ensuring accuracy in estimating anaemia prevalence, especially in LMIC settings for further interventions.