Population-specific pediatric reference intervals for complete blood count in Vietnamese children and their impact on clinical classification

Abstract Objectives To establish age- and sex-specific reference intervals (RI) for complete blood count (CBC) parameters in healthy Vietnamese children aged 0 to Methods A community-based cross-sectional study included 3,885 healthy Vietnamese children aged 0 to Results All CBC parameters showed age-related variation, supporting age-specific RI. Sex differences were limited to erythrocyte parameters, including red blood cell count, hemoglobin, and hematocrit, emerging after puberty; sex partitioning was unnecessary for most analytes. Application of the Vietnamese vs. CALIPER reference intervals in an outpatient cohort resulted in bidirectional reclassification, with 0.0–32.6 % of CALIPER-abnormal results reclassified as normal and 0.0–24.4 % of CALIPER-normal results reclassified as abnormal, depending on the analyte. Conclusions This study establishes population-based pediatric CBC RI for Vietnamese children. Non-local pediatric RI may alter abnormal flagging and result interpretation in routine practice.