Scialla Julia J, Liu Jiannong, Crews Deidra C, Guo Haifeng, Bandeen-Roche Karen, Ephraim Patti L, Tangri Navdeep, Sozio Stephen M, Shafi Tariq, Miskulin Dana C, Michels Wieneke M, Jaar Bernard G, Wu Albert W, Powe Neil R, Boulware L Ebony
Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida, USA.
Chronic Disease Research Group, Minneapolis, Minnesota, USA.
Kidney Int. 2014 Oct;86(4):798-809. doi: 10.1038/ki.2014.110. Epub 2014 Apr 30.
The estimated glomerular filtration rate (eGFR) at dialysis initiation has been rising. Observational studies suggest harm, but may be confounded by unmeasured factors. As instrumental variable methods may be less biased, we performed a retrospective cohort study of 310,932 patients who started dialysis between 2006 and 2008 and were registered in the United States Renal Data System in order to describe geographic variation in eGFR at dialysis initiation and determine its association with mortality. Patients were grouped into 804 health service areas (HSAs) by zip code. Individual eGFR at dialysis initiation averaged 10.8 ml/min per 1.73 m(2) but varied geographically. Only 11% of the variation in mean HSA-level eGFR at dialysis initiation was accounted for by patient characteristics. We calculated demographic-adjusted mean eGFR at dialysis initiation in the HSAs using the 2006 and 2007 incident cohort as our instrument and estimated the association between individual eGFR at dialysis initiation and mortality in the 2008 incident cohort using the two-stage residual inclusion method. Among 89,547 patients starting dialysis in 2008 with eGFR 5-20 ml/min per 1.73 m(2), eGFR at initiation was not associated with mortality over a median of 15.5 months (hazard ratio, 1.025 per 1 ml/min per 1.73 m(2) for eGFR 5-14 ml/min per 1.73 m(2); and 0.973 per 1 ml/min per 1.73 m(2) for eGFR 14-20 ml/min per 1.73 m(2)). Thus, there was no associated harm or benefit with early dialysis initiation in the United States.
透析开始时的估计肾小球滤过率（eGFR）一直在上升。观察性研究表明存在危害，但可能受到未测量因素的混淆。由于工具变量法可能偏差较小，我们对2006年至2008年间开始透析并在美国肾脏数据系统中注册的310,932名患者进行了一项回顾性队列研究，以描述透析开始时eGFR的地理差异并确定其与死亡率的关联。患者按邮政编码被分组到804个卫生服务区域（HSA）。透析开始时个体eGFR平均为10.8 ml/min per 1.73 m²，但存在地理差异。透析开始时HSA水平eGFR均值的变异中只有11%可由患者特征解释。我们使用2006年和2007年的发病队列作为工具计算了HSA中经人口统计学调整的透析开始时平均eGFR，并使用两阶段残差纳入法估计了2008年发病队列中透析开始时个体eGFR与死亡率之间的关联。在2008年开始透析且eGFR为5 - 20 ml/min per 1.73 m²的89,547名患者中，在中位数为15.5个月的时间里，开始时的eGFR与死亡率无关（对于eGFR为5 - 14 ml/min per 1.73 m²，每1 ml/min per 1.73 m²的风险比为1.025；对于eGFR为14 - 20 ml/min per 1.73 m²，每1 ml/min per 1.73 m²的风险比为0.973）。因此，在美国，早期开始透析没有相关的危害或益处。
