Quality assurance in the laboratory testing process: Indirect estimation of the reference intervals for platelet parameters in neonates

•Platelet parameters data from 1058 neonates in the first day of life are considered.•Two statistical indirect methods are applied.•Reference intervals for platelet parameters are established and reported.•The reported procedures are general for evaluating reference intervals in medical laboratories.

ObjectivesOne of the most powerful tools that laboratory medicine uses to help the clinical decision-making process is the reference interval (RI). By establishing their own RIs in accordance with the analytical method they apply, the laboratories contribute to the quality assurance in the laboratory testing process.Design and methodsThis study estimates the RIs of the platelet parameters in neonates for Nihon Celltac F hematology automatic analyzer. A database of 1058 venous complete blood counts in neonates in their first day of life has been processed through two different statistical methods: the simple non-parametric method and the bootstrap method.ResultsThe results give the mean ± SE(RI) for: platelet count (PLT) = 270.39 ± 0.68 (156–387 × 109/L); plateletcrit (PCT) = 0.151 ± 0.0072 (0.10–0.23%); mean platelet volume (MPV) = 5.72 ± 0.0085 (4.0–8.0 fL): platelet distribution width (PDW) = 17.67 ± 3.03 (16.3–18.9%).ConclusionsThese values are in agreement with the RI for platelet count reported in literature, but the estimated RIs of the platelet indices are different. This justifies the need for laboratories to determine their own RIs.