Division of Geriatric Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
Postgrad Med. 2010 Nov;122(6):41-5. doi: 10.3810/pgm.2010.11.2221.
Chronic kidney disease is a global public health concern. Glomerular filtration rate (GFR) prediction based on serum creatinine is used to assess renal function in the elderly. The Cockcroft-Gault (CG) formula, based on body surface area (CG/BSA formula), and the Modified Diet and Renal Disease formula (MDRD formula) are commonly used in assessing renal function in clinical practice. The objective of this study was to investigate the agreement between the GFR estimate, CG/BSA formula, and the MDRD formula in elderly outpatients.
An outpatient chart review was conducted on consecutive elderly patients aged ≥ 65 years over a 9-month period. Data regarding age, gender, cognitive status, clock drawing, weight, height, and serum creatinine were collected. Pearson's correlation coefficient, Bland-Altman plot, and kappa statistics were used for statistical analysis.
Of the 170 patients who participated in the study, 71% were cognitively impaired or had dementia. Using the CG/BSA formula, 79% of the patients had stage 3 renal disease (GFR< 60 mL/min); only 56% were diagnosed as such using the MDRD formula. There was a high correlation between the CG/BSA and MDRD formulas (Pearson correlation coefficient, 0.88; P < 0.0001). However, the kappa statistic was 0.47, indicating low agreement between the 2 formulas.
The diagnosis of having stage 3 chronic kidney disease depended on whether the CG/BSA or MDRD formula was used. A 17% discordance rate (9.61 mL/min) was seen between the MDRD and CG/BSA formulas for estimating GFR, and there was low agreement between the 2 formulas. Further studies are needed to assess which predictive formula is appropriate for elderly patients.
慢性肾脏病是一个全球性的公共卫生问题。基于血清肌酐的肾小球滤过率（GFR）预测用于评估老年人的肾功能。基于体表面积的 Cockcroft-Gault（CG）公式（CG/BSA 公式）和改良饮食和肾脏疾病公式（MDRD 公式）常用于临床评估肾功能。本研究旨在探讨老年门诊患者中 GFR 估计值、CG/BSA 公式和 MDRD 公式之间的一致性。
对 9 个月期间连续的≥65 岁老年门诊患者进行病历回顾。收集数据包括年龄、性别、认知状态、时钟绘图、体重、身高和血清肌酐。采用 Pearson 相关系数、Bland-Altman 图和 kappa 统计进行统计学分析。
在 170 名参与研究的患者中，71%存在认知障碍或痴呆。使用 CG/BSA 公式，79%的患者处于 3 期肾脏病（GFR<60 mL/min）；而仅 56%的患者使用 MDRD 公式被诊断为 3 期肾脏病。CG/BSA 和 MDRD 公式之间存在高度相关性（Pearson 相关系数为 0.88；P<0.0001）。然而，kappa 统计量为 0.47，表明这两个公式之间的一致性较低。
使用 CG/BSA 或 MDRD 公式诊断 3 期慢性肾脏病的结果不同。MDRD 和 CG/BSA 公式估计 GFR 之间存在 17%的差异率（9.61 mL/min），且这两个公式之间的一致性较低。需要进一步研究以评估哪种预测公式适用于老年患者。
