Objective: To verify the reliability and feasibility of Hoffmann method in establishing pediatric reference intervals (RI) of erythrocyte count.
Methods: Three hundreds and ninty-two thousands of hospital-based data for erythrocyte count of children aged in 1 to 17, measured by the Sysmex Xs-800i, was collected from Beijing Children's Hospital during January to December 2014. Outliers were removed using the Dixon method, then Hoffmann method was conducted to establish the gender and age stratified pediatric RIs of erythrocyte count. The erythrocyte count of 2 217 healthy children, recruited from Beijing Children's Hospital and Liaocheng Children's Hospital in Shandong province, was conducted as normal reference to verify the reliability of Hoffmann method in establishing RIs and to compare with existing RIs.
Results: In 4 subgroups as following, male aging 1 to 12 years, male aging 13 to 17 years, female aging 1 to 12 years, female aging 13 to 17 years, the RIs of erythrocyte count established using Hoffmann method were (4.1-5.4)×10(12)/L, (4.4-5.7)×10(12)/L, (4.0-5.3)×10(12)/L, (4.0-5.3)×10(12)/L, respectively. The verification results in 2 217 healthy children showed that the proportions of out of range in four subgroups were 6.17%, 8.81%, 6.22%, 7.78%, respectively.
Conclusion: Hoffmann method produce reliable RIs according with the actual situation in healthy children, which is also convenient and is worth popularizing in clinical practice.