White I R, Brunner E J, Barron J L
Department of Epidemiology and Public Health, University College London, U.K.
J Clin Epidemiol. 1995 Feb;48(2):263-7. doi: 10.1016/0895-4356(94)00127-c.
The period of urine collection used to measure excretion of catecholamines varies in epidemiological practice. We set out to compare overnight with 24 hour collection. Twenty-four subjects each collected urine for 24 hours, with the overnight urine being separately collected. The correlation of overnight and 24 hour catecholamines was highest when both measures were standardised for creatinine excretion and when creatinine excretion was adjusted for urine flow rate. The observed correlations were 0.74 for dopamine, 0.81 for noradrenaline and 0.54 for adrenaline. The use of overnight collections may therefore require a sample size up to 1.5 times as large (for noradrenaline) or 3.4 times as large (for adrenaline) to achieve the same power as with 24 hour collections. However, the figures given exaggerate the advantage of 24 hour collections if these incorporate measurement errors that are not present in overnight collections.
在流行病学实践中，用于测量儿茶酚胺排泄量的尿液收集时长各不相同。我们着手比较过夜尿液收集与24小时尿液收集的情况。24名受试者每人收集24小时尿液，并单独收集过夜尿液。当对肌酐排泄进行标准化处理且针对尿流率对肌酐排泄进行调整时，过夜与24小时儿茶酚胺之间的相关性最高。观察到的多巴胺相关性为0.74，去甲肾上腺素为0.81，肾上腺素为0.54。因此，使用过夜收集可能需要样本量增大至24小时收集的1.5倍（去甲肾上腺素）或3.4倍（肾上腺素），才能达到与24小时收集相同的效能。然而，如果24小时收集包含过夜收集不存在的测量误差，那么给出的这些数据就夸大了24小时收集的优势。
