Evidence map›Paper›PMID 41934993›Full record

ArticleThe Lancet. Haematology2026

Implications of changes in WHO haemoglobin elevation adjustment guidelines on global, regional, and national anaemia burden, 1990-2023: a population-based modelling study.

Corey J Teply, William M Gardner, Taylor S Noyes, Theresa A McHugh, Heidi A Tandiono, Ni Gusti Ayu Nanditha, Ashley A Harris, Nandita Perumal, Jackie Markt-Maloney, Brian C Howatt and 10 more

Abstract read
PubMed Full text at PMC Publisher
In one paragraph

Article in The Lancet. Haematology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

20 authors.

Corey J TeplyInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
William M GardnerInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.
Taylor S NoyesInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Theresa A McHughInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Heidi A TandionoInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Ni Gusti Ayu NandithaInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Ashley A HarrisInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Nandita PerumalInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.
Jackie Markt-MaloneyInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Brian C HowattInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Heather J TaylorInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Kyle HumphreyInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Zulfiqar A BhuttaCenter for Global Child Health, Hospital for Sick Children, Toronto, ON, Canada; Center of Excellence in Women and Child Health, Aga Khan University, Karachi, Pakistan.
Domenico GirelliSection of Internal Medicine, Department of Medicine, University of Verona, Policlinico Giambattista Rossi, Verona, Italy.
Simon I HayInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Department of Health Metrics Sciences, University of Washington, Seattle, WA, USA.
Christopher J L MurrayInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Department of Health Metrics Sciences, University of Washington, Seattle, WA, USA.
Khaled M MusallamCenter for Research on Rare Blood Disorders (CR-RBD) and Thalassemia & Sickle Cell Center, Burjeel Cancer Institute, Burjeel Medical City, Abu Dhabi, United Arab Emirates; Department of Public Health and Epidemiology, Khalifa University, Abu Dhabi, United Arab Emirates; Division of Hematology/Oncology, Department of Pediatrics, Weill Cornell Medicine, New York, NY, USA.
Obiageli NnoduDepartment of Haematology and Blood Transfusion, College of Health Sciences and Centre of Excellence for Sickle Cell Disease Research and Training, University of Abuja, Abuja, Nigeria.
Parminder S SuchdevEmory Global Health Institute, Emory University, Atlanta, GA, USA; Center for Global Health, US Centers for Disease Control and Prevention, Atlanta, GA, USA.
Nicholas J KassebaumInstitute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA; Department of Health Metrics Sciences, University of Washington, Seattle, WA, USA; Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA; Department of Global Health, University of Washington, Seattle, WA, USA. Electronic address: nickjk@uw.edu.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAdjustment of haemoglobin concentrations for elevation is essential for anaemia assessments of both individuals and populations. Whereas the previous WHO anaemia definitions released in 2001 used an elevation adjustment derived from small sample sizes with limited representativeness, the 2024 WHO global anaemia definitions reflect empirical assessments across several geographies and settings derived from population-representative surveys. We aimed to assess the effect of these changes on estimates of global anaemia burden.

methodsIn this population-based modelling study, using an identical set of input data from population-based surveys, we created two datasets in parallel, where each input haemoglobin concentration was adjusted using the WHO 2001 and WHO 2024 elevation adjustment methods. We estimated mild, moderate, and severe anaemia prevalence by age and sex for 204 countries and territories from 1990 to 2023 for each dataset using spatiotemporal Gaussian process regression and ensemble distribution modelling. We then analysed the overall differences in anaemia prevalence and years lived with disability to assess the effect of the WHO 2024 elevation adjustment method on the global landscape of anaemia. Uncertainty was propagated in each step of the modelling process by sampling draws of the posterior distribution of each estimated quantity.

findingsGlobal anaemia prevalence for all ages and both sexes in 2023 was estimated to be 26·4% (95% uncertainty interval [UI] 22·6-31·9) using the WHO 2024 elevation adjustment method, which was 2·4 percentage points (2·2-2·7) higher than the total anaemia prevalence estimated using the WHO 2001 method (24·0% [20·6-29·3]). This increase equates to 198 million (196-199) newly enumerated cases, increasing the rank of anaemia from the third to the second largest cause of disability globally. The largest absolute increases in anaemia prevalence were in locations between 500 m and 2000 m in elevation, which include countries in eastern sub-Saharan Africa, central Asia, central America, and South America.

interpretationUnderstanding the effect of anaemia requires unbiased and comparable estimates of anaemia burden. To our knowledge, we produced the first set of global estimates of anaemia burden by location, year, age, and sex using the WHO 2024 elevation adjustment method and compared them with estimates using the previous method. Policy makers should consider this modification when designing interventions to manage and prevent anaemia, particularly in regions most affected by changes in elevation adjustment.

fundingGates Foundation.

Indexed as

AnemiaHemoglobinsAdolescentAdultAgedChildChild, PreschoolFemaleGlobal HealthHumansInfantMaleMiddle AgedPrevalenceWorld Health OrganizationYoung AdultHemoglobins

Identifiers

PMID41934993
PMCPMC13160282

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.