Prevalence of iron-deficiency anaemia in Brazilian children under 5 years of age: a systematic review and meta-analysis

Abstract

Iron-deficiency anaemia is considered an important public health problem both in wealthier countries and in those of medium and low income, especially in children under five years of age. The shortage of studies with national representativity in medium income countries, such as Brazil, prevents the knowledge of the current situation and its associated factors. We conducted a systematic review and meta-analysis to estimate the pooled prevalence of iron-deficiency anaemia in Brazilian children under five years of age and determined the factors involved in the variability of the estimates of prevalence. We collected 57 studies from the databases MEDLINE, LILACS, and Web of Science, along with the reference lists of included articles. We contacted authors for unpublished data. We did not restrict publication timespan and language. This systematic review and meta-analysis were reported according to the guidelines by PRISMA. The pooled prevalence of anaemia in children under five years of age in Brazil was 40.2% (CI95%: 36.0-44.8). The age range of the child and the period of data collection were associated with the anaemia prevalence. The pooled prevalence of anaemia was higher in children under 24 month of age (53.5% vs 30.7%; p<0.001) and in studies with data collected before 2004 (51.8% vs 32.6%; p=0.001). The efforts made by Brazilian government were successful in the reduction of anaemia in children under five years old in Brazil in the evaluated period. However, prevalence remains beyond acceptable levels for this populational group.