Kuttykrishnan Sooraj, Kalantar-Zadeh Kamyar, Arah Onyebuchi A, Cheung Alfred K, Brunelli Steve, Heagerty Patrick J, Katz Ronit, Molnar Miklos Z, Nissenson Allen, Ravel Vanessa, Streja Elani, Himmelfarb Jonathan, Mehrotra Rajnish
Kidney Research Institute, Division of Nephrology, University of Washington, Seattle, WA, USA.
University of California Irvine, Irvine, CA, USA.
Nephrol Dial Transplant. 2015 Jul;30(7):1208-17. doi: 10.1093/ndt/gfv097. Epub 2015 Apr 16.
The Institute of Medicine has identified the comparative effectiveness of renal replacement therapies as a kidney-related topic among the top 100 national priorities. Given the importance of ensuring internal and external validity, the goal of this study was to identify potential sources of bias in observational studies that compare outcomes with different dialysis modalities.
This observational cohort study used data from the electronic medical records of all patients that started maintenance dialysis in the calendar years 2007-2011 and underwent treatment for at least 60 days in any of the 2217 facilities operated by DaVita Inc. Each patient was assigned one of six dialysis modalities for each 91-day period from the date of first dialysis (thrice weekly in-center hemodialysis (HD), peritoneal dialysis (PD), less-frequent HD, home HD, frequent HD and nocturnal in-center HD).
Of the 162 644 patients, 18% underwent treatment with a modality other than HD for at least one 91-day period. Except for PD, patients started treatment with alternative modalities after variable lengths of treatment with HD; the time until a change in modality was shortest for less-frequent HD (median time = 6 months) and longest for frequent HD (median time = 15 months). Between 30 and 78% of patients transferred to another dialysis facility prior to change in modality. Finally, there were significant differences in baseline and time-varying clinical characteristics associated with dialysis modality.
This analysis identified numerous potential sources of bias in studies of the comparative effectiveness of dialysis modalities.
医学研究所已将肾脏替代疗法的比较疗效确定为100个国家优先事项中与肾脏相关的主题。鉴于确保内部和外部有效性的重要性，本研究的目的是确定比较不同透析方式结局的观察性研究中潜在的偏倚来源。
这项观察性队列研究使用了2007 - 2011历年开始维持性透析且在DaVita公司运营的2217家设施中的任何一家接受治疗至少60天的所有患者的电子病历数据。从首次透析日期起，每位患者每91天被分配六种透析方式之一（每周三次的中心血液透析（HD）、腹膜透析（PD）、低频HD、家庭HD、高频HD和夜间中心HD）。
在162644名患者中，18%至少有一个91天的时间段接受了HD以外的透析方式治疗。除PD外，患者在接受HD治疗不同时长后开始采用替代方式治疗；改为低频HD的时间最短（中位时间 = 6个月），改为高频HD的时间最长（中位时间 = 15个月）。30%至78%的患者在改变透析方式之前转至另一家透析机构。最后，与透析方式相关的基线和随时间变化的临床特征存在显著差异。
该分析确定了透析方式比较疗效研究中众多潜在的偏倚来源。
