Is there an association between early childhood caries and iron deficiency anaemia?

Clinical question To determine the association between early childhood caries (ECC) and iron deficiency anaemia (IDA).Data sources A systematic search was carried out in seven databases by two independent reviewers. Also, manual searching and grey literature screening were carried out.Study selection Cross-sectional, case-control and cohort studies that evaluated the association between ECC and IDA were included. Only publications in the English language were considered for study eligibility.Data extraction and synthesis The characteristics of the included studies - age, sex, sample size, diagnostic methods used, index used for ECC, blood parameters, odds ration/risk ratio, confidence interval, p value, outcomes and assessment of any confounders - were extracted from the included papers. The quality assessment for case-control and cohort studies was performed according to the Newcastle-Ottawa assessment scale, while the modified Newcastle-Ottawa assessment scale was used for the cross-sectional studies.Results A total of 14 publications were included for qualitative review and seven of them were included in the meta-analysis. Children affected by ECC had an increased likelihood of IDA when compared to those not affected by ECC. However, the meta-analysis showed no statistical difference in blood parameters (haemoglobin, mean corpuscular volume and serum ferritin) in children with and without ECC.Conclusions There is an association between ECC and increased odds of IDA; however, there is a lack of scientific evidence to determine a cause and effect relation or direction of association between ECC and IDA.