McGuire Barry B, Bhanji Yasin, Sharma Vidit, Frainey Brendan T, McClean Megan, Dong Caroline, Rimar Kalen, Perry Kent T, Nadler Robert B
Department of Urology, Northwestern University Feinberg School of Medicine , Chicago, Illinois.
J Endourol. 2015 Jun;29(6):730-5. doi: 10.1089/end.2014.0544. Epub 2015 Jan 7.
We aimed to understand the characteristics of patients who are less likely to submit adequate urine collections at metabolic stone evaluation.
Inadequate urine collection was defined using two definitions: (1) Reference ranges for 24-hour creatinine/kilogram (Cr/24) and (2) discrepancy in total 24-hour urine Cr between 24-hour urine collections. There were 1502 patients with ≥1 kidney stone between 1998 and 2014 who performed a 24- or 48-hour urine collection at Northwestern Memorial Hospital and who were identified retrospectively. Multivariate analysis was performed to analyze predictor variables for adequate urine collection.
A total of 2852 urine collections were analyzed. Mean age for males was 54.4 years (range 17-86), and for females was 50.2 years (range 8-90). One patient in the study was younger than 17 years old. (1) Analysis based on the Cr 24/kg definition: There were 50.7% of patients who supplied an inadequate sample. Females were nearly 50% less likely to supply an adequate sample compared with men, P<0.001. Diabetes (odds ratio [OR] 1.42 [1.04-1.94], P=0.026) and vitamin D supplementation (OR 0.64 [0.43-0.95], P=0.028) predicted receiving an adequate/inadequate sample, respectively. (2) Analysis based on differences between total urinary Cr: The model was stratified based on percentage differences between samples up to 50%. At 10%, 20%, 30%, 40%, and 50% differences, inadequate collections were achieved in 82.8%, 66.9%, 51.7%, 38.5%, and 26.4% of patients, respectively. Statistical significance was observed based on differences of ≥40%, and this was defined as the threshold for an inadequate sample. Female sex (OR 0.73 [0.54-0.98], P=0.037) predicted supplying inadequate samples. Adequate collections were more likely to be received on a Sunday (OR 1.6 [1.03-2.58], P=0.038) and by sedentary workers (OR 2.3 [1.12-4.72], P=0.023).
Urine collections from patients during metabolic evaluation for nephrolithiasis may be considered inadequate based on two commonly used clinical definitions. This may have therapeutic or economic ramifications and the propensity for females to supply inadequate samples should be investigated further.
我们旨在了解在代谢性结石评估中不太可能提交足够尿液样本的患者的特征。
使用两种定义来界定尿液收集不足：（1）24小时肌酐/千克（Cr/24）的参考范围，以及（2）两次24小时尿液收集之间24小时总尿肌酐的差异。在1998年至2014年间，有1502例肾结石患者在西北纪念医院进行了24小时或48小时尿液收集，并进行回顾性识别。进行多变量分析以分析足够尿液收集的预测变量。
共分析了2852次尿液收集。男性的平均年龄为54.4岁（范围17 - 86岁），女性为50.2岁（范围8 - 90岁）。研究中有1例患者年龄小于17岁。（1）基于Cr 24/kg定义的分析：50.7%的患者提供的样本不足。与男性相比，女性提供足够样本的可能性降低近50%，P<0.001。糖尿病（比值比[OR] 1.42 [1.04 - 1.94]，P = 0.026）和补充维生素D（OR 0.64 [0.43 - 0.95]，P = 0.02）分别预测获得足够/不足的样本。（2）基于总尿肌酐差异的分析：该模型根据样本间高达50%的百分比差异进行分层。在差异为10%、20%、30%、40%和50%时，分别有82.8%、66.9%、51.7%、38.5%和26.4%的患者收集不足。基于≥40%的差异观察到统计学意义，这被定义为不足样本的阈值。女性（OR 0.73 [0.54 - 0.98]，P = 0.037）预测提供不足样本。在周日（OR 1.6 [1.03 - 2.58]，P = 0.038）以及久坐工作者（OR 2.3 [1.12 - 4.72]，P =）更有可能获得足够的收集。
根据两种常用的临床定义，肾结石代谢评估期间患者的尿液收集可能被认为不足。这可能产生治疗或经济影响，女性提供不足样本的倾向应进一步研究。
