Milinković Neda, Ignjatović Svetlana, Zarković Milos, Radosavljević Branimir, Majkić-Singh Nada
Clin Lab. 2014;60(7):1083-9. doi: 10.7754/clin.lab.2013.130733.
The aim of this work was to determine indirect reference intervals from patients' results obtained during routine laboratory work. This could be an accurate alternative to the laborious and expensive job of producing reference intervals for populations according to international recommendations.
All the results for thyrotropin (TSH), total and free thyroxine, and triiodothyronine (T4, fT4, T3, and fT3) stored in our laboratory information system between 2008 and 2011 were included in this study. We used logarithmic transformation of the raw data to exclude outliers. After visual observation of the data distribution, we estimated non-parametric reference intervals. A standard normal deviation test was performed to test the significance of differences between subgroups.
There was no significant difference in the serum levels of the analyzed thyroid parameters, so we calculated combined reference values. However, we found a significant difference in TSH values between ambulatory and hospitalized patients, but only in 2011. Indirect reference values for TSH, T4, fT4, T3 and fT3 were 0.42 - 3.67 mIU/L, 66.0 - 136.10 nmol/L, 10.20 - 18.40 pmol/L, 1.10 - 2.39 nmol/L, and 3.17 - 5.59 pmol/L, respectively.
The indirect determination of laboratory-specific reference intervals using patients' laboratory data is a relatively easy and inexpensive method. Also, indirect reference limits will be more precise and true if skewness and kurtosis of the distribution are not too large.
本研究的目的是根据常规实验室检测结果确定间接参考区间。这可能是一种替代按照国际建议为人群制定参考区间的费力且昂贵工作的准确方法。
本研究纳入了2008年至2011年存储在我们实验室信息系统中的所有促甲状腺激素（TSH）、总甲状腺素和游离甲状腺素以及三碘甲状腺原氨酸（T4、fT4、T3和fT3）的检测结果。我们对原始数据进行对数转换以排除异常值。在直观观察数据分布后，我们估计了非参数参考区间。进行了标准正态偏差检验以测试亚组之间差异的显著性。
所分析的甲状腺参数的血清水平无显著差异，因此我们计算了合并参考值。然而，我们发现门诊患者和住院患者的TSH值存在显著差异，但仅在2011年。TSH、T4、fT4、T3和fT3的间接参考值分别为0.42 - 3.67 mIU/L、66.0 - 136.10 nmol/L、10.20 - 18.40 pmol/L、1.10 - 2.39 nmol/L和3.17 - 5.59 pmol/L。
使用患者实验室数据间接确定特定实验室参考区间是一种相对简单且廉价的方法。此外，如果分布的偏度和峰度不是太大，间接参考限将更精确和真实。
