Objective: To establish reference intervals (RIs) of thyroid hormone based on data from healthy subjects in laboratory information system (LIS) by indirect methods. Methods: Data were selected from the physical examination center in LIS of the First Hospital of Jilin University from May 2014 to December 2018. The normal distribution of the original data was checked by the Kolmogorov-Smirnov test. Skewed data were transformed into normal distribution using BOX-COX techniques, and outliers were identified by the Turkey method. The continuous percentile curve was established by coefficient of skewness-median-coefficient of variation(LMS) methods. Cut-off value of age was determined by decision trees, and the differences between groups were verified by Z-tests. P(2.5) and P(97.5) in the RIs were analyzed by non-parametric methods. Results: A total of 45 742 subjects were included in the study. There were no differences in the RI for thyroid stimulating hormone (TSH) among age groups or between men and women (Z<Z*), and the RI was 0.60-4.41mIU/L (20-79 years old). However, the levels of free triiodothyronine(FT(3)) decreased with age in males and females under 35-year-old. The RIs for FT(3) were 4.47-6.44pmol/L (20-44 years old), 4.19-6.21pmol/L (45-64 years old) and 3.90-5.85pmol/L (65-79 years old) in males, and 4.04-6.13pmol/L (20-34 years old) and 3.87-5.76pmol/L (35-79 years old) in females, respectively. The levels of free thyroxine(FT(4)) in men were higher than those in women from 20 to 49 years old, and no gender and age differences could be viewed in subjects after 50 years old (Z<Z*). The RIs for FT(4) were 13.69-21.76pmol/L (male, 20-49 years old), 12.99-20.83pmol/L (female, 20-49 years old) and 12.98-21.21pmol/L (50~79 years old). Conclusion: Establishment of RIs of thyroid hormone based on the data from LIS is simple and reliable, which is suitable for clinical laboratory application.
目的： 用实验室信息系统（LIS）中体检者的数据，探索间接法建立甲状腺激素参考区间的新方法。 方法： 取2014年5月—2018年12月吉林大学第一医院LIS中体检中心数据，K-S检验分析正态性，BOX-COX将数据转成正态分布后用Turkey方法剔离群值。偏度系数-中位数-变异系数（LMS）法拟合连续百分位数曲线，决策树判定年龄划分截点，Z检验比较组间差异，非参数法计算P(2.5)、P(97.5)。 结果： 纳入研究的体检者共计45 742名。促甲状腺激素（TSH）参考区间不同年龄及性别间差异无统计学意义（Z<Z*），参考区间为0.60~4.41 mlU/L（20~79岁）。游离三碘甲状腺原氨酸（FT(3)）男性及35岁前女性随年龄下降，男性参考区间为4.47~6.44 pmol/L（20~44岁），4.19~6.21 pmol/L（45~64岁），3.90~5.85 pmol/L（65~79岁），女性为4.04~6.13 pmol/L（20~34岁），3.87~5.76 pmol/L（35~79岁）。游离甲状腺素（FT(4)）在20~49岁男性高于女性，男性参考区间为13.69~21.67 pmol/L，女性为12.99~20.83 pmol/L，50岁后不同性别及年龄间差异无统计学意义（Z<Z*），参考区间为12.98~21.21 pmol/L（50~59岁）。 结论： 基于LIS数据建立的间接法参考区间简单可靠，适于临床实验室推广和应用。.
Keywords: Indirect method; Reference interval; Thyroid Hormones.