Hong Kong Med J 2023 Oct;29(5):432–42 | Epub 1 Aug 2023
© Hong Kong Academy of Medicine. CC BY-NC-ND 4.0
ORIGINAL ARTICLE (HEALTHCARE IN MAINLAND CHINA)
Anaemia prevalence and risk factors among children aged 6 to 23 months in rural China
L Zeng, MA, BA; W Zheng, MSc, BSc; Q Gao, PhD, MEcon; N Qiao, PhD, LLM; K Du, MEcon; A Yue, PhD, MEcon
Center for Experimental Economics in Education, Shaanxi Normal University, Xi’an, China
Corresponding author: Dr Q Gao (email@example.com)
Introduction: Anaemia is a global public health problem among children. However, few studies have examined anaemia prevalence and risk factors among Chinese children of different ages, particularly in poor rural areas. This study investigated these two aspects among children aged 6 to 23 months in poor rural areas of China.
Methods: This cross-sectional study included 1132 children aged 6 to 23 months in three prefectures of the Qinba Mountains area. A finger prick blood test for haemoglobin and anaemia was conducted, along with household surveys of socio-demographic characteristics, illness characteristics, and feeding practices. Multiple linear and logistic regression analyses were used to determine predictors of anaemia.
Results: Overall, 42.6% of children in the study displayed anaemia. Children aged 6 to 11 months had the highest anaemia prevalence (53.6%). Anaemia risk factors differed among age-groups and throughout the overall sample. Bivariate and multivariable regression results showed that continued breastfeeding, any history of formula feeding, and consumption of iron-rich or iron-fortified foods were associated with anaemia prevalence. However, continued breastfeeding and any history of formula feeding had the greatest impact across age-groups (both P<0.05).
Conclusion: Anaemia remains a severe public health problem among children aged 6 to 23 months in rural China. Healthy feeding practices, nutritional health knowledge, and nutrition improvement projects are needed to reduce the burden of anaemia among children in rural areas of China.
New knowledge added by this study
- The prevalence of anaemia among rural children was higher in the Qinba Mountains area than in the central and eastern areas of China.
- Anaemia prevalence varied among age-groups, and the lowest prevalence was observed in children aged 18 to 23 months.
- Continued breastfeeding, any history of formula feeding, and consumption of iron-rich or iron-fortified foods were associated with anaemia prevalence among children in rural China.
- The government should more closely monitor anaemia among children in rural areas and introduce relevant policies to address this issue.
- Healthy feeding practices, nutritional health knowledge, and nutrition improvement projects are needed to reduce the burden of anaemia among children in rural China.
Anaemia is a global health issue that affects one-quarter of the world’s population; it is particularly prevalent among preschool-aged children in developing countries.1 Approximately 47.4% of preschool-aged children worldwide display anaemia.1 There are three categories of factors associated with anaemia: inherited disorders, infectious diseases, and micronutrient deficiencies.2 3 Among these factors, iron deficiency is the most common cause,4 especially in China.5 There is evidence that iron deficiency anaemia affects developmental potential in children.6 7
Anaemia prevalence among children in China, particularly in poor rural areas, is higher than that in developed countries.2 3 In the United States and the Netherlands, the rate is <10%.2 The rate in urban areas of China is <20%,8 9 whereas the prevalence in rural areas is more than double that in urban areas.10 11 12 Thus, there is a need for considerable effort from the Chinese Government to ensure that regional anaemia prevalence among children aged <5 years are below 10% by 2030.13
Few studies have examined factors associated with anaemia among children of different ages, particularly in poor rural areas of China. Previous studies have shown that anaemia may be associated with the demographic, social, and health characteristics of children and their families.14 15 16 17 Feeding practices have also been associated with anaemia in children.1 18 19 20 However, few studies have extensively analysed anaemia prevalence and associated factors among children of different ages in rural China.16 21 22 For example, one study explored risk factors for anaemia in children aged 0 to 5 months and those aged 6 to 36 months; however, the age ranges were excessively broad.14 In another study exploring risk factors for anaemia in children aged <36 months, stratified according to age, relatively few potential associated factors (eg, socio-demographic and illness characteristics) were considered; there was no consideration of other potential associated factors, such as complementary feeding.18
This study was therefore conducted to explore anaemia prevalence and risk factors among children aged 6 to 23 months in poor rural areas of China; analyses were performed focusing on the overall sample and with stratification according to age. Therefore, we established three objectives: to examine anaemia prevalence among children in the study area; to identify socio-demographic and illness characteristics associated with anaemia in children; and to explore feeding practices associated with anaemia in children.
This study was conducted in 22 nationally designated poverty-stricken counties (all of which are now out of poverty) within three prefectures in the Qinba Mountains area of northwest China. By the end of 2015 in the survey year, the total population of the sample area was 8 464 200, including a rural population of 4 716 100 (55.7%). The per capita income was 20 939 yuan, which was less than half of the national per capita income (42 359 yuan) in the same period in China.23 Sample villages and households were selected in two stages. First, from each of the 22 counties, all townships (ie, the middle level of administration between county and village) that met the criteria were selected to participate in the study, with two exceptions: the township in each county containing the county government (which represents the level of county development), as well as townships containing <800 people. In total, 115 of 400 townships were included in this study. Second, in each sample township, we selected random villages with ≥10 children. All children in our target age range (6-23 months) were enrolled in the study, including premature but not congenitally abnormal children; thus, we included 1694 children and their households. Because one prefecture did not survey feeding practices, the corresponding analysis only included 1210 participants from the other two sample prefectures. In total, 1132 participants (children and their households) fully completed the survey (response rate of 93.6%).
Survey data were collected in three waves in November 2015, April 2016, and February 2017. After identification of the primary caregiver responsible for a child’s diet and care, well-trained enumerators collected information through one-on-one questionnaire interviews with the primary caregiver.
First, specific components of socio-demographic and illness characteristics were recorded in the survey. The socio-demographic characteristics included the child’s age, sex, gestational age, and birth order; the primary caregiver’s identity; maternal education and age; and whether the family received social security support (ie, government welfare for the lowest income families nationwide). Illness characteristics comprised any history of fever, cold, or diarrhoea in the previous 2 weeks.
Second, detailed information regarding the child’s feeding practices was collected via dietary recall, using a series of questions based on the ‘Indicators for assessing infant feeding practices’ compiled by the World Health Organization (WHO).24 The following definitions were used: continued breastfeeding, proportion of children aged 6 to 23 months who had received breast milk during the previous day; any history of formula feeding, proportion of children who had ever been formula-fed; minimum dietary diversity, proportion of children aged 6 to 23 months who had consumed ≥4 of the 7 food groups under WHO’s classification24 during the previous day; minimum meal frequency, proportion of children aged 6 to 23 months who consumed a meal at a standard frequency during the previous day, considering their breastfeeding status (two times for breastfed infants aged 6 to 8 months, three times for breastfed children aged 9 to 23 months, and four times for non-breastfed children aged 6 to 23 months); minimum acceptable diet, proportion of children aged 6 to 23 months who consumed a meal that met standards for minimum dietary diversity and minimum meal frequency during the previous day; and consumption of iron-rich or iron-fortified foods, proportion of children who consumed iron-rich or iron-fortified foods specifically designed for children aged 6 to 23 months during the previous day.
Third, each child’s haemoglobin (Hb) concentration and anaemia status were assessed by trained nurses from the Xi’an Jiaotong University, who performed tests on fingertip blood samples collected from all children. These analyses were performed using the HemoCue Hb201 haemoglobin analyser (HemoCue Inc, Ängelholm, Sweden), which is accurate, rapid, and convenient for children in remote rural areas.11 15 21 25 Its measurement accuracy is 1 g/L.18 We confirmed that the sample villages’ altitudes were below 1000 m; therefore, no adjustments to measured Hb concentrations were required. Anaemia status was determined according to Hb concentration and divided into four categories: non-anaemic, Hb concentration ≥110 g/L; mild, 100-109 g/L; moderate, 70-99 g/L; and severe, <70 g/L.26 Children with severe anaemia were referred to a local hospital for treatment.
Statistical analysis was performed using STATA version 15.0 (Stata Corporation, College Station [TX], United States). The children’s socio-demographic and illness characteristics, feeding practices, and anaemia statuses were summarised using descriptive statistics. In bivariate analyses, P values for differences in mean Hb concentration between subgroups were estimated using t tests. The Pearson Chi squared test was also used to compare categorical variables between anaemia and non-anaemia groups. Multiple linear regression analyses were performed to identify covariates that were significantly associated with Hb concentration. Multiple logistic regression analysis was used to identify predictors of anaemia. The threshold for statistical significance was set at P<0.05.
Socio-demographic characteristics, illness characteristics, and feeding practices
Table 1 presents the socio-demographic and illness characteristics of the 1132 children. Of these, 51.0% were boys, 5.2% were born prematurely, and more than half were first-born (54.9%). Additionally, more than half of the primary caregivers (68.9%) were the children’s mothers; the remaining primary caregivers were the children’s grandmothers. Less than one-quarter of the children’s mothers (22.5%) had >9 years of education, and more than half of them (59.4%) were aged ≤28 years. Social security support was received by 11.9% of the participating families. Approximately half of the children (55.6%) had been sick (with fever, cold, or diarrhoea) in the previous 2 weeks.
Table 1 also presents the feeding practices of the children; notably, 29.8% and 86.6% of the children had continued breastfeeding and any history of formula feeding, respectively. With respect to complementary feeding, most children (80.9%) consumed iron-rich or iron-fortified foods; however, approximately 65.0% and 44.2% of the children met the standard requirements for minimum dietary diversity and meal frequency, respectively. Moreover, only 19.9% of the children met the standard requirement for a minimum acceptable diet. All children were divided into three age-groups: 6 to 11 months (n=343), 12 to 17 months (n=472), and 18 to 23 months (n=317).
Prevalence of haemoglobin concentration and anaemia
Table 2 presents the children’s Hb concentrations and anaemia prevalence; the mean and standard deviation of their Hb concentration was 110.95 ± 0.42 g/L. Overall, 42.6% of the children had anaemia, including 21.6% with mild anaemia, 20.1% with moderate anaemia, and 0.8% with severe anaemia. A similar pattern was observed upon stratification according to age: few children had severe anaemia, and approximately one-quarter of children displayed mild or moderate anaemia in 6 to 11 months and 12 to 17 months age-groups.
As age increased across the groups (from 6-11 months to 12-17 months, and then to 18-23 months), the mean Hb concentration increased, whereas anaemia prevalence decreased. The mean and standard deviation Hb concentrations in the three groups (from youngest to oldest) were 106.85 ± 0.72 g/L, 111.10 ± 0.64 g/L, and 115.18 ± 0.78 g/L, respectively. Furthermore, children aged 6 to 11 months had the highest anaemia prevalence (53.6%), followed by children aged 12 to 17 months (43.4%) and then children aged 18 to 23 months (29.3%).
Bivariate analysis of socio-demographic and illness characteristics
Table 3 shows the bivariate associations of Hb concentration/anaemia prevalence with the children’s socio-demographic and illness characteristics, stratified according to age. Among children aged 12 to 17 months, birth order and health status were significantly associated with Hb concentration/anaemia prevalence; however, the associations were not statistically significant in the other two age-groups or the overall sample. Among children aged 12 to 17 months, Hb concentrations were significantly higher in first-born children than in non-first-born children (P=0.020). Moreover, among children aged 12 to 17 months, children who had been sick in the previous 2 weeks were more likely to display anaemia, compared with children who had not been sick (P=0.029).
Table 3. Prevalence of haemoglobin concentrations and anaemia, stratified according to socio-demographic and illness characteristics
A similar trend was observed regarding the relationship of Hb concentration/anaemia prevalence with the primary caregiver; however, the only statistically significant result was observed in the overall sample. In summary, the Hb concentration was lower (P=0.003) and anaemia prevalence was higher (P=0.001) among children whose primary caregiver was their mother, compared with children who had a different primary caregiver. Furthermore, in the overall sample and all age-groups, there were no significant binary associations between the Hb concentration/anaemia prevalence and variables such as sex, premature birth, maternal education and age, or receipt of social security support.
Bivariate analysis of feeding practice variables
Table 4 shows the bivariate associations of Hb concentration/anaemia prevalence with feeding practices. The associations varied among age-groups and in the overall sample. Children with any history of formula feeding had higher Hb concentrations and lower rates of anaemia, compared with children who had never received formula (both P<0.001); these differences were statistically significant in all age-groups. Children who had continued breastfeeding displayed lower Hb concentrations and higher rates of anaemia, compared with children who had stopped breastfeeding (both P<0.001); these differences were statistically significant among children aged 12 to 17 months (both Hb concentration and anaemia prevalence) and 18 to 23 months (anaemia prevalence only).
Table 4. Prevalence of haemoglobin concentrations and anaemia, stratified according to feeding practices
Additionally, observable complementary food–related variables were significantly associated with Hb concentration and anaemia prevalence. In the overall sample, children with feeding practices that met the minimum requirements for dietary diversity had significantly higher Hb concentrations (P<0.001) and lower rates of anaemia (P=0.005), compared with children whose feeding practices did not meet those requirements. Children with feeding practices that met the minimum meal frequency requirements had higher Hb concentrations (P=0.018), compared with children whose feeding practices did not meet those requirements. Regarding the consumption of iron-rich or iron-fortified foods, a significant positive association with Hb concentration and a significant negative association with anaemia prevalence was observed among children aged 12 to 17 months and in the overall sample (both P<0.001).
Multivariable analysis of socio-demographic and illness characteristics, and feeding practice variables
The results of multivariable analysis of the relationship between Hb concentration and anaemia prevalence are presented in Table 5. The initial multivariable model included variables related to socio-demographic and illness characteristics, continued breastfeeding, and any history of formula feeding; the results showed that Hb concentrations were significantly higher in first-born children (P=0.031) and significantly lower in children of younger mothers (P=0.032), but no factors were significantly associated with anaemia prevalence. Any history of formula feeding was positively associated with Hb concentration (P=0.031) and negatively associated with anaemia prevalence (odds ratio [OR]=0.59, 95% confidence interval [CI]=0.41-0.86; P=0.006), whereas continued breastfeeding was significantly negatively associated with Hb concentration (P=0.001) and positively associated with anaemia prevalence (OR=1.50, 95% CI=1.07-2.11; P=0.019). A subsequent multivariable model included socio-demographic and illness characteristics, as well as complementary food–related variables; the results showed that Hb concentration remained positively associated with first-born-child status (P=0.025) and younger maternal age (P=0.032), whereas consumption of iron-rich or iron-fortified foods was negatively associated with anaemia prevalence (OR=0.66, 95% CI=0.46-0.94; P=0.021). The final multivariable model included all variables; the results showed that continued breastfeeding was positively associated with anaemia prevalence (OR=1.75, 95% CI=1.21-2.51; P=0.003), whereas any history of formula feeding was negatively associated with anaemia prevalence (OR=0.57, 95% CI=0.38-0.87; P=0.010).
In this analysis of 1132 children aged 6 to 23 months in a poor rural area of China, we found that the anaemia prevalence was high in the overall sample, although it varied among age-groups. Bivariate analysis of socio-demographic characteristics, illness characteristics, and feeding practices revealed diverse risk factors among age-groups and in the overall sample. Additionally, multivariable analysis showed that feeding practice–related variables were risk factors for anaemia prevalence. Compared with complementary food–related variables, continued breastfeeding and any history of formula feeding had much greater impacts across age-groups.
Anaemia prevalence among children in rural China
Our findings revealed that 42.6% of children in the overall sample displayed anaemia, and anaemia prevalence among children in rural China varied according to age. According to WHO guidelines, anaemia prevalence exceeding 40% is a ‘severe public health problem’.26 Previous studies revealed anaemia prevalence among children in rural areas of central China (29.7%) and eastern China (24.2%)21 27; the prevalence was higher among children in our sample, indicating that urgent attention is needed regarding anaemia among children in rural areas of western China. Furthermore, our results showed that anaemia prevalence decreased with increasing age, consistent with previous reports.8 15 17 28 We found that anaemia prevalence was lower among children aged 18 to 23 months than among those aged 6 to 11 months or 12 to 17 months; this may have been related to the successful inclusion of complementary foods after 12 months of age. There is evidence that increasing iron intake from various foods contributes to a slow decrease in anaemia prevalence.26 Overall, our findings imply substantial differences in anaemia prevalence according to age; thus, analyses of anaemia in children, along with its risk factors, should consider the effect of age (in months).
Bivariate and multivariable analyses of risk factors of anaemia
Our bivariate analysis showed significant differences in risk factors for low Hb concentration and anaemia prevalence among children in the overall sample and in each age-group. These findings were consistent with the results of other studies regarding anaemia among children in China.21 22 In particular, a study of children aged 6 to 23 months showed that complementary feeding practices meeting the minimum dietary diversity requirement were negatively associated with anaemia prevalence among children aged 12 to 17 months; however, the association was not statistically significant among children aged 6 to 11 months or 18 to 23 months. Additionally, complementary feeding practices meeting the minimum meal frequency requirement were negatively associated with anaemia prevalence in all age-groups.22 Therefore, we conclude that the risk factors for anaemia prevalence in children differ according to age.
Our results also indicated that socio-demographic and illness characteristics were associated with anaemia prevalence among children in poor rural areas of China, consistent with previous findings.11 17 Specifically, birth order and a history of illness in the previous 2 weeks were statistically significant risk factors for anaemia in children aged 12 to 17 months. Regarding health status, previous studies revealed that anaemia is positively associated with a history of recurrent illness, such as diarrhoea or fever.11 19 We found that children who had been sick in the previous 2 weeks were more likely to display anaemia, presumably because they experienced a loss of appetite and had poor intestinal nutrient absorption.27 The child’s relationship with their primary caregiver was significantly associated with Hb concentration and anaemia prevalence in the overall sample. Previous studies showed greater dependence on breast milk among children whose primary caregiver was their mother; this dependence may lead to anaemia. Thus, the provision of adequate nutrition via complementary food is recommended.29
Bivariate and multivariable analyses showed that feeding practices (continued breastfeeding, any history of formula feeding, and consumption of iron-rich or iron-fortified foods) were associated with anaemia prevalence in poor rural areas of China. However, continued breastfeeding and any history of formula feeding had greater impacts on specific age-groups. Children who had continued breastfeeding displayed significantly lower Hb concentrations and higher rates of anaemia, both in the overall sample and among children aged 12 to 17 months or 18 to 23 months. These findings are consistent with the results of previous studies.30 31 32 Although the importance of breastfeeding for children before the age of 2 is widely recognised, empirical studies have shown that prolonged breastfeeding (ie, beyond 6 months of age) is positively associated with anaemia in children aged <2 years.31 32 Increases in total breastfeeding duration are associated with decreases in iron stores, implying late introduction or poor quality of complementary foods in children, as well as maternal anaemia.31 33 Accordingly, although there remains a need to encourage breastfeeding, careful monitoring of maternal and infant anaemia should be implemented, along with timely introduction of appropriate complementary foods to infants by 6 months of age; maternal diets and nutritional supplementation should also be improved.33 Children with any history of formula feeding had a higher Hb concentration and lower anaemia prevalence in each age-group, as well as the overall sample, consistent with previous findings.11 19 34 Formula feeding protects against anaemia in children, presumably because most commercially available formulas are fortified with micronutrients (eg, iron).27 Children with any history of formula feeding would have received additional iron, which have may helped to improve their anaemia status.11 Therefore, high-iron formulas are recommended for infants aged >6 months.35
In the overall sample, children with feeding practices that minimum dietary diversity standards and children who consumed iron-rich or iron-fortified foods were less likely to display anaemia. These results are consistent with the findings of studies in other rural areas of China.16 20 22 Regarding minimum dietary diversity, the WHO recommends that children aged 6 to 23 months receive a variety of foods to ensure that their nutrient requirements are met.36 A child’s needs with respect to the type and quantity of complementary foods increase with monthly age.37 Other studies have shown that the addition of complementary food in moderate amounts protects against anaemia.18 30 After 6 months of age, sources of iron for anaemia prevention are mainly derived from complementary foods.19 20 22 The consumption of iron-rich foods can reduce the risk of anaemia by improving iron storage and subsequent Hb production.19 The results of some studies have highlighted the importance of high-energy foods rich in iron, including beans, dark green leafy vegetables, meat, and viscera. These foods constitute sources of haem iron, which has better bioavailability.18 Therefore, caregivers should receive information concerning the importance of iron-rich complementary foods before they begin introducing complementary foods to their children.37
However, there is evidence that many children in rural China do not meet the standards for complementary feeding recommended by the WHO.18 22 24 Family income level substantially impacts nutritional intake.20 Although formula and complementary foods are widely available, they may not be prioritised in poor rural households.22 Because parents in such households often lack nutritional knowledge, they may assume that nutrient deficiency is unlikely; this belief can lead to inappropriate feeding in many children.20 Therefore, active intervention is needed; effective communication methods should be established to provide nutritional health knowledge and social support for family nutrition.
This study had several important limitations. First, we could not determine whether seasonal or temporal factors were associated with anaemia. Although we had some seasonal and temporal data regarding the three survey waves, key information was unavailable; thus, we could not confirm the findings of Luo et al.11 Second, although previous studies indicated that anaemia during pregnancy is a risk factor for anaemia in children,38 39 the present study lacked data regarding maternal anaemia during pregnancy; thus, we could not explore this relationship. Third, we only assessed any history of formula feeding, rather than ongoing formula feeding, which may have led to inaccurate results. Additional studies are needed to address these limitations.
Anaemia remains a severe public health problem among children aged 6 to 23 months in rural China. Continued breastfeeding was significantly positively associated with anaemia prevalence, whereas any history of formula feeding and the consumption of iron-rich or iron-fortified foods were significantly negatively associated with anaemia prevalence. Although we could not make causal inferences on the basis of findings in this cross-sectional study, our analysis provided key information concerning factors associated with anaemia prevalence among children of various ages in rural China; these findings will help to guide clinical practice and support policy formulation.
Concept or design: L Zeng, W Zheng, Q Gao.
Acquisition of data: K Du, A Yue.
Analysis or interpretation of data: L Zeng, Q Gao.
Drafting of the manuscript: W Zheng, A Yue, Q Gao.
Critical revision of the manuscript for important intellectual content: Q Gao, N Qiao.
Acquisition of data: K Du, A Yue.
Analysis or interpretation of data: L Zeng, Q Gao.
Drafting of the manuscript: W Zheng, A Yue, Q Gao.
Critical revision of the manuscript for important intellectual content: Q Gao, N Qiao.
All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.
Conflicts of interest
All authors have disclosed no conflicts of interest.
We thank the enumerators for their contribution to data collection.
This research was supported by the 111 Project (Grant No.: B16031), the National Social Science Foundation of China (Grant No.: 22BGL212), the National Natural Science Foundation of China (Grant No.: 72203134), and the Special Project of Philosophy and Social Science Research in Shaanxi Province (Grant No.: 2023QN0058). The funders had no role in study design, data collection/analysis/interpretation, or manuscript preparation.
This study protocol was approved by the Sichuan University Institutional Review Board of China (Protocol ID: 2013005-01). All caregivers of the children under investigation provided oral informed consent before participating in this study.
1. McLean E, Cogswell M, Egli I, Wojdyla D, de Benoist B. Worldwide prevalence of anaemia, WHO Vitamin and Mineral Nutrition Information System, 1993-2005. Public Health Nutr 2009;12:444-54. Crossref
2. Tolentino K, Friedman JF. An update on anemia in less developed countries. Am J Trop Med Hyg 2007;77:44-51.Crossref
3. Balarajan Y, Ramakrishnan U, Ozaltin E, Shankar AH, Subramanian SV. Anaemia in low-income and middle-income countries. Lancet 2011;378:2123-35. Crossref
4. World Health Organization. Anaemia. Available from: https://www.who.int/health-topics/anaemia#tab=tab_1. Accessed 17 May 2023.
5. Wang L, Sun Y, Liu B, et al. Is infant/toddler anemia a problem across rural China? A mixed-methods analysis. Int J Environ Res Public Health 2018;15:1825. Crossref
6. Lozoff B, Smith JB, Kaciroti N, Clark KM, Guevara S, Jimenez E. Functional significance of early-life iron deficiency: outcomes at 25 years. J Pediatr 2013;163:1260-6. Crossref
7. Deng X. Effects of iron deficiency anemia on physical development, intelligent behavior development and sleep quality of infants [in Chinese]. Pract Clin Med 2019;4:719-81.
8. Jin D, Zhuo Y, Hu L, Ruan D. Influence of iron deficiency anemia on intelligence of infants aged 6 to 36 months [in Chinese]. Chin J Woman Child Health Res 2019;30:281-3.
9. Zhang B. Analysis of the prevalence of anemia in infants and young children and the causes of transformation in a community in Shanghai [in Chinese]. Shanghai Med Pharm J 2019;40:61-2.
10. Wang L, Liang W, Zhang S, et al. Are infant/toddler developmental delays a problem across rural China? J Comp Econ 2019;47:458-69. Crossref
11. Luo R, Shi Y, Zhou H, et al. Anemia and feeding practices among infants in rural Shaanxi province in China. Nutrients 2014;6:5975-91. Crossref
12. Nie J, Yang J, Zhang L, Li Y, Yang J. Current situation and influencing factors of anemia in infants in poor rural areas in western China. J East China Norm Univ Sci 2019;37:58-69.
13. The State Council Information Office of the People’s Republic of China. Circular of the General Office of the State Council on the Issuance of China’s Food and Nutrition Development Program (2017-2030) [in Chinese]. State Office 2017. Available from: http:
// Accessed 9 Sep 2021. www .scio .gov.cn /xwfbh /xwbfbh /wqfbh /42311 /44583 /xgzc44589 /Document /1695253 /1695253.htm
14. Gao W, Yan H, Wang D, Dang S, Pei L. Severity of anemia among children under 36 months old in rural western China. PLoS One 2013;8:e62883. Crossref
15. Chen L, Li Y, Li Y, Yang F, Bi X. Iron deficiency anemia status and influencing factors among children aged 6 to 23 months in rural minority areas in Yunnan [in Chinese]. Chin J Child Health Care 2017;25:85-7.
16. Huang Y, Wang L, Huo J, et al. Prevalence and causes of anaemia in children aged 6-23 months in rural Qinghai, China: findings from a cross-sectional study. BMJ Open 2019;9:e031021. Crossref
17. Yang Y, Liu L, Yang W, Zhang S, Wang Y. State and influencing factors for anemia of infants aged 0-18 months in rural area of Shaanxi province [in Chinese]. Matern Child Health Care China 2013;28:1897-9.
18. Luo RF, Liang X, Liu CF, Zhang LX, Yue A. Risk factors for anemia in infants aged 6-12 months from rural areas of southern Shaanxi Province, China [in Chinese]. Chin J Contemp Pediatr 2016;18:736-41.
19. Sun S, Wu Y, Chen Y, Hao G, Zhou H. Analysis of the influencing factors of infant anemia in underdeveloped rural areas of southern Shaanxi [in Chinese]. Chin J Dis Control Prev 2015;19:1138-41.
20. Zhou X, Fang JQ, Luo JY, et al. Prevalence and influencing factors of anemia among 6-23 months old children in poor rural areas [in Chinese]. Chin J Public Health 2017;33:1302-5.
21. Xin QQ, Chen BW, Yin DL, et al. Prevalence of anemia and its risk factors among children under 36 months old in China. J Trop Pediatr 2017;63:36-42. Crossref
22. Hipgrave DB, Fu X, Zhou H, et al. Poor complementary feeding practices and high anaemia prevalence among infants and young children in rural central and western China. Eur J Clin Nutr 2014;68:916-24. Crossref
23. Shaanxi Provincial Bureau of Statistics. Shaanxi statistical yearbook [in Chinese]. 2016. Available from: http://tjj.shaanxi.gov.cn/tjsj/ndsj/tjnj/sxtjnj/index.html?2016. Accessed 17 May 2023.
24. World Health Organization. Indicators for assessing infant and young child feeding practices (Part I—definitions). Conclusions of a consensus meeting held 6-8 November 2007 in Washington, DC, USA. 2008. Available from: https:
//apps.who.int. Accessed 23 Dec 2021. /iris /bitstream /handle /10665 /43895 /9789241596664_eng.pdf ;jsession id=96860366C0058393 F12BC11CE25498BA?sequence=1
25. Seguin P, Kleiber A, Chanavaz C, Morcet J, Mallédant Y. Determination of capillary hemoglobin levels using the HemoCue system in intensive care patients. J Crit Care 2011;26:423-7. Crossref
26. World Health Organization. Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. 2011. Available from: https:
//apps.who.int. Accessed 4 Jul 2023. /iris /bitstream /handle /10665 /85839 /WHO_NMH_NHD_ MNM_11.1_eng.pdf? sequence= 22&isAllowed=y
27. Huang Z, Jiang FX, Li J, Jiang D, Xiao TG, Zeng JH. Prevalence and risk factors of anemia among children aged 6-23 months in Huaihua, Hunan Province. BMC Public Health 2018;18:1267. Crossref
28. Huo J, Sun J, Fang Z, et al. Effect of home-based complementary food fortification on prevalence of anemia among infants and young children aged 6 to 23 months in poor rural regions of China. Food Nutr Bull 2015;36:405-14. Crossref
29. Li H, Xiao J, Liao M, et al. Anemia prevalence, severity and associated factors among children aged 6-71 months in rural Hunan Province, China: a community-based cross-sectional study. BMC Public Health 2020;20:989. Crossref
30. Hopkins D, Emmett P, Steer C, Rogers I, Noble S, Emond A. Infant feeding in the second 6 months of life related to iron status: an observational study. Arch Dis Child 2007;92:850-4. Crossref
31. Hu S, Tan H, Peng A, et al. Disparity of anemia prevalence and associated factors among rural to urban migrant and the local children under two years old: a population based cross-sectional study in Pinghu, China. BMC Public Health 2014;14:601. Crossref
32. Wu LX, Wang PW, Liu S, Li SY, Yan H, Zuo D. Analysis on breast feeding and anemia status among infants under 2 years old in rural areas of Hubei province [in Chinese]. Chin J Child Health Care 2013;21:1175-7.
33. Meinzen-Derr JK, Guerrero ML, Altaye M, Ortega-Gallegos H, Ruiz-Palacios GM, Morrow AL. Risk of infant anemia is associated with exclusive breast-feeding and maternal anemia in a Mexican cohort. J Nutr 2006;136:452-8. Crossref
34. Dong C, Ge P, Zhang C, et al. Effects of different feeding practices at 0 to 6 months and living economic conditions on anemia prevalence of infants and young children [in Chinese]. J Hyg Res 2013;42:596-9.
35. Vendt N, Grünberg H, Leedo S, Tillmann V, Talvik T. Prevalence and causes of iron deficiency anemias in infants aged 9 to 12 months in Estonia. Medicina (Kaunas) 2007;43:947-52. Crossref
36. World Health Organization. Indicators for assessing infant and young child feeding practices: definitions and measurement methods. 2021. Available from: https://www.who.int/publications/i/item/9789240018389. Accessed 20 Sep 2021.
37. Lu P, Wang J, Jiang W, et al. Feeding status of 0~23-month-old infants in poor rural areas of Gansu Province from 2018 to 2019 [in Chinese]. Wei Sheng Yan Jiu 2020;49:731-43.
38. Wang L. Investigation on risk factors of iron deficiency anemia in infants [in Chinese]. Chin J Woman Child Health Res 2017;(S4):434-5.
39. Shukla AK, Srivastava S, Verma G. Effect of maternal anemia on the status of iron stores in infants: a cohort study. J Family Community Med 2019;26:118-22. Crossref