scholarly journals Preanalytic and analytic factors affecting the measurement of haemoglobin concentration: impact on global estimates of anaemia prevalence

2021 ◽  
Vol 6 (7) ◽  
pp. e005756
Author(s):  
Leila M Larson ◽  
Sabine Braat ◽  
Mohammed Imrul Hasan ◽  
Martin N Mwangi ◽  
Fernando Estepa ◽  
...  
Keyword(s):  
Public Health ◽  
Pregnant Women ◽  
Haemoglobin Concentration ◽  
Preschool Age ◽  
Quality Assurance Programme ◽  
Factors Affecting ◽  
Percentage Points ◽  
Severity Classification ◽  
Prevalence Estimates ◽  
Global Estimates

The accuracy of haemoglobin concentration measurements is crucial for deriving global anaemia prevalence estimates and monitoring anaemia reduction strategies. In this analysis, we examined and quantified the factors affecting preanalytic and analytic variation in haemoglobin concentrations. Using cross-sectional data from three field studies (in children, pregnant and nonpregnant women), we examined the difference in haemoglobin concentration between venous-drawn and capillary-drawn blood measured by HemoCue (ie, preanalytic) and modelled how the bias observed may affect anaemia prevalence estimates in population surveys and anaemia public health severity classification across countries. Using data from an international quality assurance programme, we examined differences due to instrumentation from 16 different haematology analyzers (ie, analytic). Results indicated that capillary and venous haemoglobin concentrations are not in agreement (bias +5.7 g/L (limits of agreement (LoA) −11.2, 22.6) in preschool age children; range from −28 g/L to +20 g/L in pregnant women; bias +8.8 g/L (LoA −5.2, 22.9) in non-pregnant women). The bias observed could introduce changes in population survey estimates of anaemia of up to −20.7 percentage points in children and −28.2 percentage points in non-pregnant women after venous adjustment. Analytic variation was minimal and unlikely to influence the diagnosis of anaemia. These findings suggest that global estimates of anaemia prevalence derived from capillary haemoglobin, as they often are, may be inaccurate and lead to erroneous public health severity classification, but that point-of-care, or other, instruments should not introduce variation if properly used.

Variability in haemoglobin concentration by measurement tool and blood source: an analysis from seven countries

2020 ◽  
pp. jclinpath-2020-206717
Author(s):  
Aviva I Rappaport ◽  
Crystal D Karakochuk ◽  
Sonja Y Hess ◽  
Ralph D Whitehead, Jr. ◽  
Sorrel M L Namaste ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Venous Blood ◽  
Sampling Site ◽  
Haemoglobin Concentration ◽  
Measurement Tool ◽  
Blood Collection ◽  
Large Variability ◽  
Factors Affecting ◽  
Haematology Analyser ◽  
Ghanaian Women

ObjectiveWe explore factors such as the blood sampling site (capillary vs venous), the equipment (HemoCue vs automated haematology analyser) and the model of the HemoCue device (201+ vs 301) that may impact haemoglobin measurements in capillary and venous blood.MethodsEleven studies were identified, and bias, concordance and measures of diagnostic performance were assessed within each study.FindingsOur analysis included 11 studies from seven countries (Cambodia, India, The Gambia, Ghana, Laos, Rwanda and USA). Samples came from children, men, non-pregnant women and pregnant women. Mean bias ranged from −8.7 to 2.5 g/L in Cambodian women, 6.2 g/L in Laotian children, 2.4 g/L in Ghanaian women, 0.8 g/L in Gambian children 6–23 months and 1.4 g/L in Rwandan children 6–59 months when comparing capillary blood on a HemoCue to venous blood on a haematology analyser. Bias was 8.3 g/L in Indian non-pregnant women and 2.6 g/L in Laotian children and women and 1.5 g/L in the US population when comparing capillary to venous blood using a HemoCue. For venous blood measured on the HemoCue compared with the automated haematology analyser, bias was 5.3 g/L in Gambian pregnant women 18–45 years and 11.3 g/L in Laotian children 6–59 months.ConclusionOur analysis found large variability in haemoglobin concentration measured on capillary or venous blood and using HemoCue Hb 201+ or Hb 301 or automated haematology analyser. We cannot ascertain whether the variation is due to differences in the equipment, differences in capillary and venous blood, or factors affecting blood collection techniques.

Understanding Economic and Health Factors Impacting the Spread of COVID-19 Disease (Preprint)

2020 ◽  
Author(s):  
Aleksandr Farseev ◽  
Yu-Yi Chu-Farseeva ◽  
Yang Qi ◽  
Daron Benjamin Loo
Keyword(s):  
Public Health ◽  
Quantitative Research ◽  
Health Indicators ◽  
Initial Study ◽  
Disease Spread ◽  
Factors Affecting ◽  
Country Level ◽  
Development Scenarios ◽  
Health Factors ◽  
Country Clusters

UNSTRUCTURED The rapid spread of the Coronavirus 2019 disease (COVID-19) had drastically impacted life all over the world. While some economies are actively recovering from this pestilence, others are experiencing fast and consistent disease spread, compelling governments to impose social distancing measures that have put a halt on routines, especially in densely-populated areas. Aiming at bringing more light on key economic and public health factors affecting the disease spread, this initial study utilizes a quantitative statistical analysis based on the most recent publicly-available COVID-19 datasets. The study had shown and explained multiple significant relationships between the COVID-19 data and other country-level statistics. We have also identified and statistically profiled four major country-level clusters with relation to different aspects of COVID-19 development and country-level economic and health indicators. Specifically, this study has identified potential COVID-19 under-reporting traits as well as various economic factors that impact COVID-19 Diagnosis, Reporting, and Treatment. Based on the country clusters, we have also described the four disease development scenarios, which are tightly knit to country-level economic and public health factors. Finally, we have highlighted the potential limitation of reporting and measuring COVID-19 and provided recommendations on further in-depth quantitative research.

scholarly journals Cohort profile: the Chinese Pregnant Women Cohort Study and Offspring Follow-up (CPWCSaOF)

BMJ Open ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. e044933
Author(s):  
Tianchen Lyu ◽  
Yunli Chen ◽  
Yongle Zhan ◽  
Yingjie Shi ◽  
Hexin Yue ◽  
...  
Keyword(s):  
Cohort Study ◽  
Pregnant Women ◽  
First Trimester ◽  
Health Problems ◽  
Environmental Data ◽  
Geographical Information ◽  
Obstetric Outcomes ◽  
Factors Affecting ◽  
Link Type

PurposeA multicentre prospective cohort study, known as the Chinese Pregnant Women Cohort Study (CPWCS), was established in 2017 to collect exposure data during pregnancy (except environmental exposure) and analyse the relationship between lifestyle during pregnancy and obstetric outcomes. Data about mothers and their children’s life and health as well as children’s laboratory testing will be collected during the offspring follow-up of CPWCS, which will enable us to further investigate the longitudinal relationship between exposure in different periods (during pregnancy and childhood) and children’s development.Participants9193 pregnant women in 24 hospitals in China who were in their first trimester (5–13 weeks gestational age) from 25 July 2017 to 26 November 2018 were included in CPWCS by convenience sampling. Five hospitals in China which participated in CPWCS with good cooperation will be selected as the sample source for the Chinese Pregnant Women Cohort Study (Offspring Follow-up) (CPWCS-OF).Findings to dateSome factors affecting pregnancy outcomes and health problems during pregnancy have been discovered through data analysis. The details are discussed in the ‘Findings to date’ section.Future plansInfants and children and their mothers who meet the criteria will be enrolled in the study and will be followed up every 2 years. The longitudinal relationship between exposure (questionnaire data, physical examination and biospecimens, medical records, and objective environmental data collected through geographical information system and remote sensing technology) in different periods (during pregnancy and childhood) and children’s health (such as sleeping problem, oral health, bowel health and allergy-related health problems) will be analysed.Trail registration numberCPWCS was registered with ClinicalTrials.gov on 18 January 2018: NCT03403543. CPWCS-OF was registered with ClinicalTrials.gov on 24 June 2020: NCT04444791.

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