Abstract：
OBJECTIVE: Biological variation is a relevant component of diagnostic uncertainty. In addition to within-subject and between-subject variation, preanalytical variation also includes components that contribute to biological variability. Among these, daily recurring, i.e., diurnal physiological variation is of particular importance, as it contains both a random and a non-random component if the exact time of blood collection is not known.
METHODS: We introduce four time-dependent characteristics (TDC) of diurnal variations for measurands to assess the relevance and extent of time dependence on the evaluation of laboratory results.
RESULTS: TDC address (i) a threshold for considering diurnality, (ii) the expected relative changes per time unit, (iii) the permissible time interval between two blood collections at different daytimes within which the expected time dependence does not exceed a defined analytical uncertainty, and (iv) a rhythm-expanded reference change value. TDC and their importance will be exemplified by the measurands aspartate aminotransferase, creatine kinase, glucose, thyroid stimulating hormone, and total bilirubin. TDCs are calculated for four time slots that reflect known blood collection schedules, i.e., 07:00-09:00, 08:00-12:00, 06:00-18:00, and 00:00-24:00. The amplitude and the temporal location of the acrophase are major determinates impacting the diagnostic uncertainty and thus the medical interpretation, especially within the typical blood collection time from 07:00 to 09:00.
CONCLUSIONS: We propose to check measurands for the existence of diurnal variations and, if applicable, to specify their time-dependent characteristics as outlined in our concept.
METHODS: We introduce four time-dependent characteristics (TDC) of diurnal variations for measurands to assess the relevance and extent of time dependence on the evaluation of laboratory results.
RESULTS: TDC address (i) a threshold for considering diurnality, (ii) the expected relative changes per time unit, (iii) the permissible time interval between two blood collections at different daytimes within which the expected time dependence does not exceed a defined analytical uncertainty, and (iv) a rhythm-expanded reference change value. TDC and their importance will be exemplified by the measurands aspartate aminotransferase, creatine kinase, glucose, thyroid stimulating hormone, and total bilirubin. TDCs are calculated for four time slots that reflect known blood collection schedules, i.e., 07:00-09:00, 08:00-12:00, 06:00-18:00, and 00:00-24:00. The amplitude and the temporal location of the acrophase are major determinates impacting the diagnostic uncertainty and thus the medical interpretation, especially within the typical blood collection time from 07:00 to 09:00.
CONCLUSIONS: We propose to check measurands for the existence of diurnal variations and, if applicable, to specify their time-dependent characteristics as outlined in our concept.
摘要：
目的：生物变异是诊断不确定性的相关因素。除了主体内和主体间的变化，分析前变异还包括有助于生物变异性的成分。其中,每天重复，即，昼夜生理变化特别重要，因为如果不知道确切的采血时间，它包含随机和非随机成分。
方法：我们介绍了被测量的昼夜变化的四个时间依赖性特征（TDC），以评估时间依赖性与实验室结果评估的相关性和程度。
结果：TDC解决（i）考虑随机性的阈值，(ii)每个时间单位的预期相对变化，（iii）在不同的白天两次采血之间的允许时间间隔，在该时间间隔内，预期的时间依赖性不超过定义的分析不确定性，和(iv)节奏扩展参考变化值。TDC及其重要性将以天冬氨酸转氨酶为例，肌酸激酶，葡萄糖，促甲状腺激素,和总胆红素.TDC是针对四个反映已知采血时间表的时隙计算的，即，07:00-09:00、08:00-12:00、06:00-18:00和00:00-24:00。顶相的振幅和时间位置是影响诊断不确定性并因此影响医学解释的主要决定因素。特别是在典型的血液采集时间从07:00到09:00。
结论：我们建议检查被测量是否存在昼夜变化，如果适用，指定它们在我们的概念中概述的时间依赖性特征。
方法：我们介绍了被测量的昼夜变化的四个时间依赖性特征（TDC），以评估时间依赖性与实验室结果评估的相关性和程度。
结果：TDC解决（i）考虑随机性的阈值，(ii)每个时间单位的预期相对变化，（iii）在不同的白天两次采血之间的允许时间间隔，在该时间间隔内，预期的时间依赖性不超过定义的分析不确定性，和(iv)节奏扩展参考变化值。TDC及其重要性将以天冬氨酸转氨酶为例，肌酸激酶，葡萄糖，促甲状腺激素,和总胆红素.TDC是针对四个反映已知采血时间表的时隙计算的，即，07:00-09:00、08:00-12:00、06:00-18:00和00:00-24:00。顶相的振幅和时间位置是影响诊断不确定性并因此影响医学解释的主要决定因素。特别是在典型的血液采集时间从07:00到09:00。
结论：我们建议检查被测量是否存在昼夜变化，如果适用，指定它们在我们的概念中概述的时间依赖性特征。
