(P24-022-24) Updated WHO Guidelines on the Assessment of Haemoglobin and Cutoffs for Defining Anaemia

Objectives: Appropriate guidelines for measurement of haemoglobin and definition of anaemia are crucial for both clinical and public health medicine but require consideration of the range of complexities across different populations. The main objective of this WHO guideline is to provide updated, locally adaptable, clear, evidence-informed global recommendations on the haemoglobin cutoffs to define anaemia and the best practices to measure it in individuals and populations as a strategy to improve the diagnosis of anaemia, grounded in gender, equity and human rights.

Methods: The evidence that informed haemoglobin cutoffs to define anaemia in individuals and populations was based on an analysis of haemoglobin data from healthy populations, general population databases, and systematic reviews. The information was discussed by the WHO Guideline Development Group and normative statements were developed. In addition to the direct and indirect evidence and its overall certainty, aspects on feasibility, values and preferences were also considered.

Results: The guideline contains normative statements on the recommended cutoff to define anaemia in different age groups and includes the suggested adjustments in haemoglobin concentrations to account for differences in settings and populations such as elevation above sea level of the place of residence, smoking, genetic background, and infection and inflammation.

The guideline recommends modification of the current haemoglobin cutoffs for defining anaemia for children 6–23 months of age, the use of the existing cutoffs for pregnant women in the second trimester, and new adjustments by elevation and smoking.

The guideline also provides recommendations on the type of blood sample and the method of haemoglobin concentration determination and the classification of anaemia as a public health problem.

Conclusions: This guideline will help Member States in their efforts to make informed decisions on the appropriate tools to support assessing and reducing the global burden of anaemia as an important public health priority.

Funding Sources: World Health Organization, Department of Nutrition and Food Safety