# A systematic review and meta—analysis of the prevalence and associated factors of iron—deficiency anemia among Chinese children under 6 years of age

## TL;DR

This study finds that about 20% of Chinese children under 6 have iron-deficiency anemia, with higher rates in rural areas and specific risk factors like young age and low birth weight.

## Contribution

The study provides a comprehensive meta-analysis of IDA prevalence and risk factors in Chinese children under 6, highlighting regional and demographic disparities.

## Key findings

- The overall IDA prevalence in Chinese children under 6 is 20.61%, with rural areas showing higher rates than urban areas.
- Key risk factors include male sex, age 6–24 months, low birth weight, maternal anemia, and premature birth.
- Mixed or artificial feeding and early complementary feeding are protective against IDA.

## Abstract

This meta-analysis aimed to determine the prevalence of iron-deficiency anemia (IDA) in Chinese children under 6 years of age and identify the associated risk factors.

A comprehensive search was conducted for studies published up to 15 January 2025 in English and Chinese databases (PubMed, Embase, Web of Science, CNKI, and WanFang Data). A random-effects model was used to synthesize prevalence data and risk factors.

Twenty-three studies involving 93,570 children (19,994 with IDA) were included. The overall IDA prevalence was 20.61% (95% CI: 14.68%–26.54%), with higher rates in rural areas (29.96%) compared to urban areas (13.28%). Significant risk factors for IDA included male sex (OR = 1.35), age 6-12 months (OR = 4.10), age 13–24 months (OR = 2.66), low birth weight (<2,500 g) (OR = 1.46), maternal anemia during pregnancy (OR = 2.50), cesarean delivery (OR = 1.18), and premature birth (OR = 2.15). Protective factors included mixed feeding (OR = 0.59), artificial feeding (OR = 0.54), and early introduction of complementary feeding (<6 months) (OR = 0.57). Respiratory diseases, diarrhoea, and formula feeding were not significant risk factors. Meta-regression showed no impact of study design or sample size on these associations.

Risk factors for IDA in Chinese children under 6 years of age include male sex, younger age (6–24 months), low birth weight, maternal anemia, cesarean delivery, and premature birth. Mixed or artificial feeding and early complementary feeding may protect against IDA. Further large-scale worldwide studies are needed to confirm these findings and inform public health strategies.