Analysis and comparison of reference intervals of complete blood cell count with the published standards

Abstract

Objective To analyze the status of reference intervals（RIs）of complete blood cell count（CBC）in China and compare them with the published standards. Methods The RIs information of CBC（containing the items of WBC, RBC, Hb, HCT, MCV, MCH, MCHC and PLT）were collected by the External Quality Assessment（EQA）software from laboratories participated in the Second Complete Blood Cell Count EQA Program in 2013, which including the sources of RIs, the lower and upper limits of RIs and the validation information of RIs. The sources and validation information of RIs were analyzed by Microsoft Excel 2007 using all data except those from maternal and child care service center, children′s hospital and corporations. The outliers of limits of RIs were excluded according to the International Federation of Clinical Chemistry（IFCC）guidelines ，then data were analyzed by SPSS 13.0. The mean of the upper and lower limits of the RIs were compared with the published standards by the t-test. Results Totally 299（57.72%）of 518 laboratories reported were using RIs according to National Clinical Laboratory Operation Rules, while 112（26.62%）labs were using RIs from instrument/reagent manufacturer instructions, 411（80.00%）labs did not validate the RIs they used, of which 258（50.00%）did not know how to validate RIs. The deviation of the maximum and the minimum ranged from 16% to 70%. More than one third laboratories did not separate RIs of RBC, Hb and HCT according to the gender. The upper and lower limits of WBC and MCV of most laboratories were higher, while those of RBC(male/female), PLT and Hb(male) were lower than that from the published standard. The RIs of MCH was narrower than that from the published standard. Meanwhile, HCT, MCHC (male/female) and Hb (female) were near the upper and lower limits of published standards. Conclusions At present, the RIs of CBC used in laboratories is chaotic, which is significantly different from the published standard. On the basis of standardization, the RIs of published standard result from a multi-center study in Chinese people should be preferred.（Chin J Lab Med,2014,37:539-543） Key words: Blood cell count; Reference values; Quality control