Parkin Patricia C, Hamid Jemila, Borkhoff Cornelia M, Abdullah Kawsari, Atenafu Eshetu G, Birken Catherine S, Maguire Jonathon L, Azad Azar, Higgins Victoria, Adeli Khosrow
Division of Pediatric Medicine and the Pediatric Outcomes Research Team (PORT), Hospital for Sick Children, Toronto, Ontario, Canada.
Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
BMJ Paediatr Open. 2017 Aug 31;1(1):e000074. doi: 10.1136/bmjpo-2017-000074. eCollection 2017.
The primary objective was to establish reference intervals for laboratory tests used to assess iron status in young children using the Clinical and Laboratory Standards Institute guidelines. A secondary objective was to compare the lower limit of the reference interval with the currently recommended cut-off value for haemoglobin and serum ferritin in children 1-3 years of age.
Blood samples were obtained from healthy children recruited during scheduled health supervision visits with their primary care physician. For our primary objective, outliers were removed; age partitions were selected and analysis of variance and pairwise comparisons were made between adjacent partitions; reference intervals and 90% CIs were calculated. For our secondary objective, we determined the proportion of children misclassified using the lower limit reference interval compared with the cut-off value.
Samples from 2305 male and 2029 female participants (10 days to 10.6 years) were used to calculate age and sex-specific reference intervals for laboratory tests of iron status. There were statistically significant differences between adjacent age partitions for most analytes. Approximately 10% of children 1-3 years of age were misclassified (underestimated) using the lower limit of the reference intervals rather than the currently recommended cut-off values for haemoglobin and serum ferritin.
Clinical laboratories may consider adopting published paediatric reference intervals. Reference intervals may misclassify (underestimate) children with iron deficiency as compared with currently recommended cut-off values. Future research on decision limits derived from clinical studies of outcomes is a priority.
主要目的是根据临床和实验室标准协会的指南，建立用于评估幼儿铁状态的实验室检测的参考区间。次要目的是比较参考区间的下限与目前推荐的1 - 3岁儿童血红蛋白和血清铁蛋白的临界值。
从在与初级保健医生进行定期健康监督访视期间招募的健康儿童中采集血样。对于主要目的，去除异常值；选择年龄分区并进行方差分析以及相邻分区之间的成对比较；计算参考区间和90%置信区间。对于次要目的，我们确定了与临界值相比，使用下限参考区间误分类（低估）的儿童比例。
来自2305名男性和2029名女性参与者（10天至10.6岁）的样本用于计算铁状态实验室检测的年龄和性别特异性参考区间。大多数分析物在相邻年龄分区之间存在统计学显著差异。使用参考区间下限而非目前推荐的血红蛋白和血清铁蛋白临界值时，1 - 3岁儿童中约10%被误分类（低估）。
临床实验室可考虑采用已发表的儿科参考区间。与目前推荐的临界值相比，参考区间可能会将缺铁儿童误分类（低估）。未来从结局临床研究得出决策限的研究是优先事项。
