Department of Urology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
J Endourol. 2013 Mar;27(3):374-8. doi: 10.1089/end.2012.0216. Epub 2013 Feb 14.
Abstract Purpose: To determine whether one vs two 24-hour urine collections is optimal in the metabolic evaluation of nephrolithiasis.
We retrospectively reviewed all 24-hour urine collections performed at our tertiary stone clinic from July 1997 to February 2012. We identified patients with two 24-hour urine collections performed ≤10 days apart. Samples were analyzed by an outside laboratory for the standard urinary parameters. For each parameter, pairwise t tests were performed and Pearson correlation coefficients were calculated to compare samples 1 and 2. In addition, the number of cases that changed from normal to abnormal or vice versa was also evaluated for each parameter and the Kappa statistic was calculated.
A total of 813 subjects submitted two 24-hour urine collections ≤10 days apart. Mean age was 53.2 years, and mean body mass index was 28.8 kg/m(2). Based on creatinine 24/kg, subset analysis was performed for all properly collected samples (n=236). Using pairwise t test, 24-hour urine volume (P=0.0365) and phosphorus (P=0.0387) showed a statistically significant difference between samples 1 and 2. None of the other urinary parameters demonstrated a statistically significant difference when means were compared (pairwise t test, P>0.05), (range 0.061-0.9983). Pearson correlation demonstrated a high degree of correlation between two 24-hour urines for all variables (r=0.66-0.95, each P<0.0001). Depending on the urinary parameter assessed, 5.5% to 44.9% of patients changed from normalcy to abnormality, or vice versa.
A single 24-hour urine collection may have changed clinical decision making in up to 45% of patients. Therefore, we recommend two collections to optimize the diagnostic yield and appropriately target stone prevention strategies.
确定在肾结石的代谢评估中，一次或两次 24 小时尿液收集哪个更优。
我们回顾性分析了 1997 年 7 月至 2012 年 2 月在我们的三级结石诊所进行的所有 24 小时尿液收集。我们确定了在 10 天内进行两次 24 小时尿液收集的患者。样本由外部实验室分析，以获得标准尿液参数。对于每个参数，我们进行了配对 t 检验，并计算了 Pearson 相关系数，以比较样本 1 和 2。此外，我们还评估了每个参数从正常变为异常或反之的病例数，并计算了 Kappa 统计量。
共有 813 名患者提交了两次 24 小时尿液收集，时间间隔不超过 10 天。平均年龄为 53.2 岁，平均 BMI 为 28.8kg/m²。根据肌酐 24/kg，我们对所有正确收集的样本（n=236）进行了亚组分析。使用配对 t 检验，样本 1 和 2 之间的 24 小时尿量（P=0.0365）和磷（P=0.0387）有统计学差异。当比较平均值时，其他尿液参数均无统计学差异（配对 t 检验，P>0.05）（范围 0.061-0.9983）。Pearson 相关分析显示，所有变量的两次 24 小时尿液之间均具有高度相关性（r=0.66-0.95，P<0.0001）。根据评估的尿液参数，5.5%至 44.9%的患者从正常变为异常，或者反之。
单次 24 小时尿液收集可能会使多达 45%的患者的临床决策发生变化。因此，我们建议进行两次收集，以优化诊断效果并适当确定结石预防策略。
