Trocchi Pietro, Girndt Matthias, Scheidt-Nave Christa, Markau Silke, Stang Andreas
Center of Clinical Epidemiology, c/o Institute of Medical Informatics, Biometry and Epidemiology (IMIBE), University Hospital Essen, Hufelandstr. 55, 45147, Essen, Germany.
Department of Internal Medicine II, Medical Faculty of the Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle (Saale), Germany.
BMC Nephrol. 2017 Nov 28;18(1):341. doi: 10.1186/s12882-017-0749-5.
Estimating equations are recommended by clinical guidelines as the preferred method for assessment of glomerular filtration rate (GFR). The aim of the study was to compare population-based prevalence estimates of decreased kidney function in Germany defined by an estimated GFR (eGFR) <60 ml/min/1.73m using different equations.
The study included 7001 participants of the German Health Interview and Examination Survey for Adults 2008-2011 (DEGS1) for whom GFR was estimated using the Modification of Diet in Renal Disease study equation (MDRD), the revised Lund-Malmö equation (LM), the Full Age Spectrum creatinine equation (FAScre), the Chronic Kidney Disease Epidemiology Collaboration equations with creatinine and cystatin C (CKD-EPIcrecys), with creatinine (CKD-EPIcre) and with cystatin C (CKD-EPIcys). Bland-Altman plots were used to evaluate the agreement between the equations.
Prevalence estimates of decreased kidney function were: 2.1% (CKD-EPIcys), 2.3% (CKD-EPIcrecys), 3.8% (CKD-EPIcre), 5.0% (MDRD), 6.0% (LM) and 6.9% (FAScre). The systematic differences between the equations were smaller by comparing either equations that include serum cystatin C or equations that include serum creatinine alone and increased considerably by increasing eGFR.
Prevalence estimates of decreased kidney function vary considerably according to the equation used for estimating GFR. Equations that include serum cystatin C provide lower prevalence estimates if compared with equations based on serum creatinine alone. However, the analysis of the agreement between the equations according to eGFR provides evidence that the equations may be used interchangeably among persons with pronounced decreased kidney function. The study illustrates the implications of the choice of the estimating equation in an epidemiological setting.
临床指南推荐使用估算方程作为评估肾小球滤过率（GFR）的首选方法。本研究的目的是比较使用不同方程对德国基于人群的估算肾小球滤过率（eGFR）<60 ml/min/1.73m²定义的肾功能下降患病率的估算。
该研究纳入了2008 - 2011年德国成人健康访谈与检查调查（DEGS1）的7001名参与者，使用肾脏病膳食改良研究方程（MDRD）、修订的隆德 - 马尔默方程（LM）、全年龄谱肌酐方程（FAScre）、含肌酐和胱抑素C的慢性肾脏病流行病学协作方程（CKD - EPIcrecys）、含肌酐的方程（CKD - EPIcre）和含胱抑素C的方程（CKD - EPIcys）估算GFR。采用布兰德 - 奥特曼图评估各方程之间的一致性。
肾功能下降的患病率估算分别为：2.1%（CKD - EPIcys）、2.3%（CKD - EPIcrecys）、3.8%（CKD - EPIcre）、5.0%（MDRD）、6.0%（LM）和6.9%（FAScre）。通过比较包含血清胱抑素C的方程或仅包含血清肌酐的方程，各方程之间的系统差异较小，且随着eGFR的增加差异显著增大。
根据用于估算GFR的方程不同，肾功能下降的患病率估算差异很大。与仅基于血清肌酐的方程相比，包含血清胱抑素C的方程得出的患病率估算较低。然而，根据eGFR对各方程之间一致性的分析表明，这些方程在肾功能明显下降的人群中可互换使用。该研究说明了在流行病学背景下选择估算方程的影响。
