Trends in ferritin measurements in children and adolescents: A Finnish 9‐year observational study

AIM: A lack of stored iron, indicated by low serum ferritin, has been associated with various clinical symptoms. There are no longitudinal data on the frequency of ferritin measurements in children and adolescents. METHODS: A total of 2834 children aged <18 years with serum ferritin and other anaemia‐related blood parameters taken during an outpatient visit between 2012 and 2019 were investigated. Patients with acute infections were excluded. Nationwide temporal and regional variations and correlations with public information searches through Google were analysed. RESULTS: A significant increase in the frequency of ferritin measurements was seen starting in 2018, with a 47‐fold rise in 2019 compared to 2012. A simultaneous escalation in Google Search activity was seen. Deficiency of stored iron was relatively common: 21.6% of children with normal haemoglobin and 14.9% of non‐anaemic children with normal red cell indices exhibited ferritin levels below 15 μg/L. CONCLUSION: Ferritin measurement has increased greatly among children and adolescents. Our results suggest that public interest and popular trends can significantly influence health care practices. This calls for further investigation into the causes and consequences of such a phenomenon. Prospective randomised intervention studies are needed to evaluate the utility of iron supplementation in patients with low iron storage levels.