Department of Biological, Environmental & Occupational Health Sciences, University of Ghana School of Public Health, Legon, Ghana.
Department of Clinical Laboratory Sciences, Faculty of Health Sciences, Yamaguchi University Graduate School of Medicine, Ube, Japan.
Int J Lab Hematol. 2020 Dec;42(6):705-717. doi: 10.1111/ijlh.13296. Epub 2020 Sep 3.
In Ghana, diagnostic laboratories rely on reference intervals (RIs) provided by manufacturers of laboratory analyzers which may not be appropriate. This study aimed to establish RIs for hematological parameters in adult Ghanaian population.
This cross-sectional study recruited 501 apparently healthy adults from two major urban areas in Ghana based on the protocol by IFCC Committee for Reference Intervals and Decision Limits. Whole blood was tested for complete blood count (CBC) by Sysmex XN-1000 analyzer, sera were tested for iron and ferritin by Beckman-Coulter/AU480, for transferrin, vitamin-B12, and folate was measured by Centaur-XP/Siemen. Partitioning of reference values by sex and age was guided by "effect size" of between-subgroup differences defined as standard deviation ratio (SDR) based on ANOVA. RIs were derived using parametric method with application of latent abnormal values exclusion method (LAVE), a multifaceted method of detecting subjects with abnormal results in related parameters.
Using SDR ≥ 0.4 as a threshold, RIs were partitioned by sex for platelet, erythrocyte parameters except mean corpuscular constants, and iron markers. Application of LAVE had prominent effect on RIs for majority of erythrocyte and iron parameters. Global comparison of Ghanaian RIs revealed lower-side shift of RIs for leukocyte and neutrophil counts, female hemoglobin and male platelet count, especially compared to non-African countries.
The LAVE effect on many hematological RIs indicates the need for deliberate secondary exclusion for proper derivation of RIs. Obvious differences in Ghanaian RIs compared to other countries underscore the importance of country-specific RIs for improved clinical decision-making.
在加纳，诊断实验室依赖于实验室分析仪制造商提供的参考区间（RI），但这些参考区间可能并不适用。本研究旨在为加纳成年人群建立血液学参数的 RI。
本横断面研究根据 IFCC 参考区间和决策限委员会的方案，从加纳两个主要城市招募了 501 名看似健康的成年人。使用 Sysmex XN-1000 分析仪对全血进行了全血细胞计数（CBC）检测，使用 Beckman-Coulter/AU480 对血清中铁和铁蛋白进行了检测，使用 Centaur-XP/Siemen 对转铁蛋白、维生素 B12 和叶酸进行了检测。参考值的分组按性别和年龄进行，指导原则是基于方差分析的组间差异“效应大小”，定义为标准差比（SDR）。使用参数法和潜在异常值排除法（LAVE）推导 RI，后者是一种检测相关参数中异常结果的多方面方法。
使用 SDR≥0.4 作为阈值，按性别对血小板、红细胞参数（除平均红细胞常数外）和铁标志物进行了 RI 分组。LAVE 的应用对大多数红细胞和铁参数的 RI 有显著影响。加纳 RI 的全球比较显示，白细胞和中性粒细胞计数、女性血红蛋白和男性血小板计数的 RI 下限发生了偏移，与非非洲国家相比，这种偏移尤其明显。
LAVE 对许多血液学 RI 的影响表明，需要进行有针对性的二次排除，以正确推导 RI。与其他国家相比，加纳 RI 存在明显差异，突出了为改善临床决策制定制定特定国家 RI 的重要性。
