ABSTRACT
INTRODUCTION: In order to correctly manage the paediatric patients affected with haemostatic disorders, age-appropriate reference intervals should be used. The purpose of this study was to establish age-specific reference intervals for prothrombin time (PT), thrombin time (TT), activated partial thromboplastin time (aPTT) and fibrinogen (Fg). METHODS: In this study, a total of 34 234 apparently healthy children and adolescents aged 0-15 years were chosen as reference individuals. PT, TT, aPTT and Fg were performed on the STA-R coagulation analyzer. Outliers were eliminated using the Dixon D/R ratio rule. Partitioning by age was achieved using Harris and Boyd's standard normal deviate test. The lower (2.5th percentiles) and upper (97.5 percentiles) reference intervals were established using the nonparametric method. RESULTS: Compared with the adult group, the median time of PT was significantly different in the groups consisting of children aged 0-15 days, 15 days-1 month, 1-6 months and 11-15 years. The median time of APTT and TT was significantly prolonged in all paediatric age groups than in the adult group (P < .05). Compared with the adult group, the median values of Fg were significantly different in the groups consisting of children aged 0-15 days and 2-15 years. Our results showed that all coagulation assays required partitioning by age. CONCLUSION: Our results suggest that results of coagulation assays are highly dependent on age, and that age-specific reference intervals must be used to ensure proper evaluation of paediatric coagulation assays.
