Microcytosis and possible early iron deficiency in paediatric inpatients: a retrospective audit

BACKGROUND Iron deficiency anaemia is a common paediatric problem worldwide, with significant neurodevelopmental morbidity if left untreated. A decrease in the mean corpuscular volume (MCV) can be used as a surrogate marker for detecting early iron deficiency prior to definitive investigation and treatment. An audit cycle was therefore undertaken to evaluate and improve the identification, follow-up and treatment of abnormally low MCV results amongst the paediatric inpatients in an English district general hospital. METHODS The audit cycle was performed retrospectively over two three-month periods (February to April 2006; September to November 2006), amongst patients aged between one month and 16 years that had full blood counts performed whilst admitted on the paediatric ward. Patients with at least one abnormally low MCV result were identified, and their notes reviewed. We looked for any underlying explanation for the result, adequate documentation of the result as abnormal, and instigation of follow-up or treatment. In-between the two audit periods, the results of the first audit period were presented to the medical staff and suggestions were made for improvements in documentation and follow-up of abnormal results. The z-test was used to test for equality of proportions between the two audit samples. RESULTS Out of 701 inpatients across both audit periods that had full blood counts, 61 (8.7%) had a low MCV result. Only 15% of patients in each audit period had an identifiable explanation for their low MCV values. Amongst the remaining 85% with either potentially explicable or inexplicable results, there was a significant increase in documentation of results as abnormal from 25% to 91% of cases between the first and second audit periods (p = 0.00 using z-test). However, there was no accompanying increase in the proportion of patients who received follow-up or treatment for their abnormal results. CONCLUSION Abnormal red cell indices that may indicate iron deficiency are frequently missed amongst paediatric inpatients. Medical staff education and the use of appropriate protocols or pathways could further improve detection and treatment rates in this setting.