LAUSR

BACKGROUND Reference intervals (RIs) are normal ranges of clinical indicators established from healthy subjects, and comparing test results with RIs is the first step for clinicians in differentiating between healthy and diseased subjects. Capillary blood is widely used in complete blood count (CBC) tests in children; however, capillary blood-based RIs for the CBC parameters are still lacking for all pediatric populations. The aim of this study was to establish capillary blood-based RIs for the CBC parameters in children aged 3 months to 18 years in Beijing. METHODS A total of 6799 capillary blood specimens from children were collected, including 3832 males and 2967 females aged 3 months to 18 years, and CBC parameters were analyzed. Data analysis, RI calculations, and 90% confidence interval (CI) calculations were performed according to CLSI C28-A3 guidelines. RESULTS Capillary blood RIs for 22 CBC parameters were established in children aged 3 months to 18 years. The levels of most red blood cell-related parameters increased with age and were generally higher in males than in females. White blood cell counts were relatively stable, with no obvious upward or downward trends from 3 months to 18 years of age. Platelet levels decreased within the first year and tended to be stable thereafter. Further validation with 458 healthy children illustrated that the verified results were within the established RIs with a 90%-100% proportion. CONCLUSION We established capillary blood RIs for 22 CBC parameters in children across a broad age range in Beijing.