IMPORTANCE Anemia, defined as low hemoglobin (Hb) concentration insufficient to meet an individual's physiological needs, is the most common blood condition worldwide. OBJECTIVE To evaluate the current World Health Organization (WHO) Hb cutoffs for defining anemia among persons who are apparently healthy and to assess threshold validity with a biomarker of tissue iron deficiency and physiological indicator of erythropoiesis (soluble transferrin receptor [sTfR]) using multinational data. DESIGN, SETTING, AND PARTICIPANTS In this cross-sectional study, data were collected and evaluated from 30 household, population-based nutrition surveys of preschool children aged 6 to 59 months and nonpregnant women aged 15 to 49 years during 2005 to 2016 across 25 countries. Data analysis was performed from March 2020 to April 2021. EXPOSURE Anemia defined according to WHO Hb cutoffs. MAIN OUTCOMES AND MEASURES To define the healthy population, persons with iron deficiency(ferritin <12 ng/mL for children or <15 ng/mL for women), vitamin A deficiency (retinol-binding protein or retinol <20.1 μg/dL), inflammation (C-reactive protein >0.5 mg/dL or α-1-acid glycoprotein >1 g/L), or known malaria were excluded. Survey-specific, pooled Hb fifth percentile cutoffs were estimated. Among individuals with Hb and sTfR data, Hb-for-sTfR curve analysis was conducted to identify Hb inflection points that reflect tissue iron deficiency and increased erythropoiesis induced by anemia. RESULTSA total of 79 950 individuals were included in the original surveys. The final healthy sample was 13 445 children (39.9% of the original sample of 33 699 children; 6750 boys [50.2%]; mean [SD] age 32.9 [16.0] months) and 25 880 women (56.0% of the original sample of 46 251women; mean [SD] age, 31.0 [9.5] years). Survey-specific Hb fifth percentile among children ranged from 7.90 g/dL (95% CI, 7.54-8.26 g/dL in Pakistan) to 11.23 g/dL (95% CI, 11.14-11.33 g/dL in the US), and among women from 8.83 g/dL (95% CI, 7.77-9.88 g/dL in Gujarat, India) to 12.09 g/dL (95% CI, 12.00-12.17 g/dL in the US). Intersurvey variance around the Hb fifth percentile was low (3.5% for women and 3.6% for children). Pooled fifth percentile estimates were 9.65 g/dL (95% CI, 9.26-10.04 g/dL) for children and 10.81 g/dL (95% CI, 10.35-11.27 g/dL) for women. The Hb-for-sTfR curve demonstrated curvilinear associations with sTfR inflection points occurring at Hb of 9.61 g/dL (95% CI, 9.55-9.67 g/dL) among children and 11.01 g/dL (95% CI, 10.95-11.09 g/dL) among women. CONCLUSIONS AND RELEVANCECurrent WHO cutoffs to define anemia are higher than the pooled fifth percentile of Hb among persons who are outwardly healthy and from nearly all surveyspecific estimates. The lower proposed Hb cutoffs are statistically significant but also reflect (continued) Key Points Question Are the current World Health Organization (WHO) hemoglobin (Hb) cutoffs to define anemia comparable to statistical and physiological Hb cutoffs calculated using representative surveys from multiple countries collected in t...
Background Accurate assessment of iron and vitamin A status is needed to inform public health decisions, but most population-level iron and vitamin A biomarkers are independently influenced by inflammation. Objectives We aimed to assess the reproducibility of the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) regression approach to adjust iron [ferritin, soluble transferrin receptor (sTfR)] and vitamin A [retinol-binding protein (RBP), retinol] biomarkers for inflammation (α-1-acid glycoprotein and C-reactive protein). Methods We conducted a sensitivity analysis comparing unadjusted and adjusted estimates of iron and vitamin A deficiency using the internal-survey regression approach from BRINDA phase 1 (16 surveys in children, 10 surveys in women) and 13 additional surveys for children and women (BRINDA phase 2). Results The relations between inflammation and iron or vitamin A biomarkers were statistically significant except for vitamin A biomarkers in women. Heterogeneity of the regression coefficients across surveys was high. Among children, internal-survey adjustments increased the estimated prevalence of depleted iron stores (ferritin <12 µg/L) by a median of 11 percentage points (pp) (24 pp and 9 pp in BRINDA phase 1 and phase 2, respectively), whereas estimates of iron-deficient erythropoiesis (sTfR >8.3 mg/L) decreased by a median of 15 pp (15 pp and 20 pp in BRINDA phase 1 and phase 2, respectively). Vitamin A deficiency (RBP <0.7 µmol/L or retinol <0.7 µmol/L) decreased by a median of 14 pp (18 pp and 8 pp in BRINDA phase 1 and phase 2, respectively) in children. Adjustment for inflammation in women resulted in smaller differences in estimated iron deficiency than in children. Conclusions Our findings are consistent with previous BRINDA conclusions that not accounting for inflammation may result in an underestimation of iron deficiency and overestimation of vitamin A deficiency. Research is needed to understand the etiology of the heterogeneity in the regression coefficients before a meta-analyzed regression correction can be considered.
Background The associations between anemia and household water source and sanitation remain unclear. Objectives We aimed to assess the associations between anemia and household water source or sanitation in preschool children (PSC; age 6–59 mo) using population-based surveys from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project. Methods We analyzed national and subnational data from 21 surveys, representing 19 countries (n = 35,963). Observations with hemoglobin (Hb) and ≥1 variable reflecting household water source or sanitation were included. Anemia was defined as an altitude-adjusted Hb concentration <110 g/L. Household water source and sanitation variables were dichotomized as “improved” or “unimproved.” Poisson regressions with robust variance estimates were conducted for each survey, adjusting for child sex, age, household socioeconomic status, maternal education, and type of residence. Results Access to an improved water source and improved sanitation ranged from 29.9% (Burkina Faso) to 98.4% (Bangladesh, 2012), and from 0.2% (Kenya, 2007) to 97.4% (Philippines), respectively. Prevalence of anemia ranged from 20.1% (Nicaragua) to 83.5% (Bangladesh, 2010). Seven surveys showed negative associations between anemia and improved sanitation. Three surveys showed association between anemia and improved water, with mixed directions. Meta-analyses suggested a protective association between improved household sanitation and anemia [adjusted prevalence ratio (aPR) = 0.88; 95% CI: 0.79, 0.98], and no association between improved household water and anemia (aPR = 1.00; 95% CI: 0.91, 1.10). There was heterogeneity across surveys for sanitation (P < 0.01; I2 = 66.3%) and water (P < 0.01; I2 = 55.8%). Conclusions Although improved household sanitation was associated with reduced anemia prevalence in PSC in some surveys, this association was not consistent. Access to an improved water source in general had no association with anemia across surveys. Additional research could help clarify the heterogeneity between these conditions across countries to inform anemia reduction programs.
Environmental justice (EJ) efforts aimed at capacity building are essential to addressing environmental health disparities; however, limited attention has been given to describing these efforts. This study reports findings from a scoping review of community–academic partnerships and community-led efforts to address environmental inequities related to air, water, and land pollution in the United States. Literature published in peer-reviewed journals from January 1986 through March 2018 were included, and community capacity theory was applied as a framework for understanding the scope of capacity-building and community change strategies to address EJ concerns. Paired teams of independent analysts conducted a search for relevant articles (n = 8452 citations identified), filtered records for content abstraction and possible inclusion (n = 163) and characterized selected studies (n = 58). Most articles implemented activities that were aligned with community capacity dimensions of citizen participation (96.4%, n = 53), community power (78%, n = 45), leadership (78%, n = 45), and networks (81%, n = 47); few articles identified a direct policy change (22%, n = 13), and many articles discussed the policy implications of findings for future work (62%, n = 36). This review synthesizes three decades of efforts to reduce environmental inequities and identifies strategic approaches used for strengthening community capacity.
Objectives Current WHO hemoglobin (Hb) cutoffs (< 110 g/L, 6–59mo; < 120 g/L, 15–49y non-pregnant women) to define anemia were established in 1967 and validated in 1980 s among iron replete USA survey participants. Our objective was to examine the consistency of Hb cutoffs from multiple countries and age-variations in Hb concentrations among apparently healthy people using contemporary data. Methods We analyzed altitude and smoking (women only)-adjusted Hb data from 25 countries for preschool children (PSC, 6–59mo, 24 surveys, n = 35,088) and women of reproductive age (WRA, 15–49y, 20 surveys, n = 50,846) from the Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project. Healthy was defined as: [ferritin >12 µg/L (< 5y), >15 µg/L ( >5y)], RBP or retinol >0.7 µmol/L, CRP ≤ 5 mg/L or AGP ≤ g/L, and no malaria (if measured)]. We examined Hb levels, cut-offs at specified percentiles (%ile) and country variations with age-adjusted generalized mixed models using country as random intercept. Results The final analytic sample was 41,314; the healthy inclusion criteria resulted in 17–88% data loss of the original data depending on country. Age and country-adjusted mean (SE) of Hb was 116.9 (1.44)g/L for PSC, and 129.1 (1.49)g/L for WRA and was significantly (P < 0.001) associated with age in PSC but not in WRA, and varied by country (pheterogeniety < .001, in each target group). Country explained 22% of the total Hb variance for each group. The pooled countries’ Hb at the 5%ile was 94 g/L for PSC [range: 79 g/L (Pakistan) - 113 g/L (USA], and 110 g/L for WRA [92 g/L (Nigeria) - 121 g/L (USA)]. Conclusions The high heterogeneity in Hb cutoffs among healthy people from different countries suggests that a single Hb cutoff for anemia may not work for every country. This multinational analysis suggests that different approaches may be warranted to establish Hb cutoffs. Funding Sources Bill & Melinda Gates Foundation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.