Establishment of reference intervals for complete blood count parameters in venous blood for children in the Xiamen area, China

Objectives To observe changes in the complete blood count (CBC) venous blood parameters of healthy children and establish appropriate reference intervals (RIs). Methods Overall, 4066 healthy children were selected and divided into four groups: infants, toddlers, preschool‐age children and school‐age children. Venous blood was analysed for 17 parameters. Outlier data for each parameter were eliminated and RIs were established based on the Clinical and Laboratory Standards Institute C28‐A3c guideline. Results The RIs for certain parameters differed among the different age groups. The white blood cell (WBC) count differed among the four age groups. The variation trends for absolute neutrophil count in all age groups were opposite to those for WBC and absolute lymphocyte count. The mean absolute eosinophil count values were significantly higher in the infant group than in the other groups. The RIs for red blood cell were identical across all age groups except in infants. The mean Hb level for infants was significantly lower than that for the other age groups. The mean and RI for platelet count were significantly higher in the infant group than in the other groups. Conclusions There are dynamic variations in the values reported for measurements of most CBC parameters in children. Hence, such results should always be interpreted according to the child's age. Thus establishing appropriate RIs for different age groups in paediatrics is essential.