Herts Brian R, Schneider Erika, Poggio Emilio D, Obuchowski Nancy A, Baker Mark E
Division of Radiology, Cleveland Clinic, 9500 Euclid Ave, Cleveland, OH 44195, USA.
Radiology. 2008 Jul;248(1):106-13. doi: 10.1148/radiol.2481071528. Epub 2008 May 5.
To determine whether using estimated glomerular filtration rate (eGFR) values rather than serum creatinine levels to identify patients with renal insufficiency facilitates any substantial change in the number of outpatients scheduled for computed tomography (CT) who are considered at increased risk for contrast medium-induced nephropathy.
The study was HIPAA compliant and institutional review board approved for medical chart review; the requirement for informed patient consent was waived. Patients (n = 5138; 2569 women, 2569 men, 753 African Americans, 4385 non-African Americans) examined during a 2-year period formed the final study group after exclusion of patients undergoing dialysis (n = 49), for whom no age data were recorded (n = 9), and younger than 18 years (n = 113). Patient age, sex, and race and the blood urea nitrogen, albumin, and serum creatinine levels most recently measured within 6 months before CT were obtained from the electronic medical records. The number of patients with creatinine levels higher than 1.4 mg/dL was directly compared with the number of patients with eGFR values (calculated with four- and six-variable Modification of Diet in Renal Disease [MDRD] equations) lower than 60 mL/min/1.73 m(2) by using the two-tailed McNemar test. For 2689 patients, data to calculate the eGFR by using the four-variable equation were available, and for 2005 patients, data to calculate the eGFR by using the six-variable equation were available.
Among the outpatients scheduled to undergo CT, the percentage of patients with an eGFR lower than 60 mL/min/1.73 m(2) was significantly greater than the percentage of patients with a creatinine level higher than 1.4 mg/dL for both the four-variable (412 [15.3%] vs 166 [6.2%] of 2689 patients) and the six-variable (346 [17.3%] vs 117 [5.8%] of 2005 patients) MDRD equation groups (P < .001).
A significantly higher number of outpatients scheduled for contrast medium-enhanced CT met the National Kidney Foundation criteria for renal insufficiency when the MDRD equations were used to estimate the glomerular filtration rate compared with the number of outpatients who met the criteria on the basis of elevated creatinine levels.
确定使用估算肾小球滤过率（eGFR）值而非血清肌酐水平来识别肾功能不全患者，是否会使计划接受计算机断层扫描（CT）且被认为发生造影剂肾病风险增加的门诊患者数量出现显著变化。
本研究符合健康保险流通与责任法案（HIPAA）要求，经机构审查委员会批准进行病历审查；无需患者知情同意。在2年期间接受检查的患者（n = 5138；2569名女性，2569名男性，753名非裔美国人，4385名非非裔美国人）在排除接受透析的患者（n = 49，未记录年龄数据）（n = 9）以及年龄小于18岁的患者（n = 113）后组成最终研究组。从电子病历中获取患者的年龄、性别、种族以及CT检查前6个月内最近一次测量的血尿素氮、白蛋白和血清肌酐水平。使用双尾McNemar检验直接比较肌酐水平高于1.4mg/dL的患者数量与eGFR值（使用四变量和六变量肾病饮食改良[MDRD]方程计算）低于60mL/min/1.73m²的患者数量。对于2689名患者，有数据可用于使用四变量方程计算eGFR，对于2005名患者，有数据可用于使用六变量方程计算eGFR。
在计划接受CT检查的门诊患者中，四变量MDRD方程组（2689名患者中，412名[15.3%] vs 166名[6.2%]）和六变量MDRD方程组（2005名患者中，346名[17.3%] vs 117名[5.8%]）中，eGFR低于60mL/min/1.73m²的患者百分比显著高于肌酐水平高于1.4mg/dL的患者百分比（P <.001）。
与基于肌酐水平升高符合标准的门诊患者数量相比，当使用MDRD方程估算肾小球滤过率时，计划接受造影剂增强CT检查的门诊患者中符合美国国家肾脏基金会肾功能不全标准的患者数量显著更多。
