Investigation and analysis of the reference intervals for complete blood cell counting in 110 maternal and child health service centers and children′s hospitals in China

Objective To investigate and analyze the source and upper and lower limits of the reference interval of children′s complete blood count in 110 maternal and child health hospitals and children′s hospitals nationwide. Methods Laboratories submitted the data of reference intervals via external quality assessment (EQA) software which was based on the web. To collect the results of reference intervals questionnaires on complete blood cell counting of children in laboratory departments of 110 maternal and child care service centers and children′s hospitals in China in 2017. Questionnaires include information on the source of reference intervals for 18 items of complete blood count, whether to verify, upper and lower limits, grouping, methods used, instruments, reagents, and calibrators. Data was analyzed using Microsoft Excel 2007 and SPSS 22.0. The median, P25, P75were obtained, and rank sum test were used to determine whether there were statistical differences between groups. Results The results of 110 laboratories were obtained after rejecting invalid data. The reference intervals were mainly derived from operating procedures and the laboratories themselves, of which 50.5%-53.6% of the laboratories were validated. The white blood cell counting reference intervals gradually decreased from birth to adolescence, and the value was close to that of adults. The reference intervals of red blood cell counting and hemoglobin were close to that of adults except in the neonatal period. The value of the reference intervals of hematocrit slightly decreased with age. The difference between RBC, Hgb, HCT in reference intervals between groups was statistically significant when grouped by gender (P<0.05) . The reference intervals of white blood cell counting were less grouped by gender (5 laboratories) , and the difference among groups was not statistically significant. There were no statistically significant differences in the reference intervals of elements between the two measurement systems that Sysmex XN series and Sysmex XS-800i/XS-1000i/XS 500i/XS 900i series. Conclusions The establishment of reference intervals for children′s complete blood cell counting was urgently needed. The reference intervals of the complete blood cell counting item had statistical significance in both age and gender. It was suggested that the industry standard of children′s complete blood cell counting reference intervals should be established based on age and gender. Key words: Blood cell count; Reference values; Child