Held P J, Port F K, Wolfe R A, Stannard D C, Carroll C E, Daugirdas J T, Bloembergen W E, Greer J W, Hakim R M
United States Renal Data System, University of Michigan, Ann Arbor, USA.
Kidney Int. 1996 Aug;50(2):550-6. doi: 10.1038/ki.1996.348.
The relationship between the delivered dose of hemodialysis and patient mortality remains somewhat controversial. Several observational studies have shown improved patient survival with higher levels of delivered dialysis dose. However, several other unmeasured variables, changes in patient mix or medical management may have impacted on this reported difference in mortality. The current study of a U.S. national sample of 2,311 patients from 347 dialysis units estimates the relationship of delivered hemodialysis dose to mortality, with a statistical adjustment for an extensive list of comorbidity/risk factors. Additionally this study investigated the existence of a dose beyond which more dialysis does not appear to lower mortality. We estimated patient survival using proportional hazards regression techniques, adjusting for 21 patient comorbidity/risk factors with stratification for nine Census regions. The patient sample was 2,311 Medicare hemodialysis patients treated with bicarbonate dialysate as of 12/31/90 who had end-stage renal disease for at least one year. Patient follow-up ranged between 1.5 and 2.4 years. The measurement of delivered therapy was based on two alternative measures of intradialytic urea reduction, the urea reduction ratio (URR) and Kt/V (with adjustment for urea generation and ultrafiltration). Hemodialysis patient mortality showed a strong and robust inverse correlation with delivered hemodialysis dose whether measured by Kt/V or by URR. Mortality risk was lower by 7% (P = 0.001) with each 0.1 higher level of delivered Kt/V. (Expressed in terms of URR, mortality was lower by 11% with each 5 percentage point higher URR; P = 0.001). Above a URR of 70% or a Kt/V of 1.3 these data did not provide statistical evidence of further reductions in mortality. In conclusion, the delivered dose of hemodialysis therapy is an important predictor of patient mortality. In a population of dialysis patients with a very high mortality rate, it appears that increasing the level of delivered therapy offers a practical and efficient means of lowering the mortality rate. The level of hemodialysis dose measured by URR or Kt/V beyond which the mortality rate does not continue to decrease, though not well defined with this study, appears to be above current levels of typical treatment of hemodialysis patients in the U.S.
血液透析的实际透析剂量与患者死亡率之间的关系仍存在一定争议。多项观察性研究表明，较高的透析剂量可改善患者生存率。然而，其他一些未测量的变量、患者构成的变化或医疗管理方式可能影响了报告的死亡率差异。本研究以美国347个透析单位的2311名患者为全国样本，评估实际血液透析剂量与死亡率的关系，并对一系列广泛的合并症/风险因素进行了统计调整。此外，本研究还调查了是否存在一个剂量阈值，超过该阈值后增加透析剂量似乎并不能降低死亡率。我们使用比例风险回归技术估计患者生存率，并对21种患者合并症/风险因素进行调整，同时按9个人口普查区域进行分层。患者样本为截至1990年12月31日接受碳酸氢盐透析液治疗、患有终末期肾病至少一年的2311名医疗保险血液透析患者。患者随访时间为1.5至2.4年。实际透析治疗剂量的测量基于两种透析中尿素清除率的替代指标，即尿素清除率（URR）和Kt/V（对尿素生成和超滤进行调整）。无论通过Kt/V还是URR测量，血液透析患者的死亡率与实际血液透析剂量均呈现出强烈且显著的负相关。每增加0.1的实际Kt/V水平，死亡风险降低7%（P = 0.001）。（以URR表示，每增加5个百分点的URR，死亡率降低11%；P = 0.001）。当URR超过70%或Kt/V超过1.3时，这些数据并未提供死亡率进一步降低的统计学证据。总之，血液透析治疗的实际剂量是患者死亡率的重要预测指标。在死亡率极高的透析患者群体中，表示增加实际透析治疗水平似乎是降低死亡率的一种切实有效的方法。尽管本研究并未明确界定，但通过URR或Kt/V测量的血液透析剂量水平，超过该水平死亡率不再继续下降，这一剂量水平似乎高于美国目前血液透析患者的典型治疗水平。
