Lowrie Edmund G, Li Zhensheng, Ofsthun Norma, Lazarus J Michael
Fresenius Medical Care (North America), Lexington, MA 02420-9192, USA.
Nephrol Dial Transplant. 2004 Nov;19(11):2823-30. doi: 10.1093/ndt/gfh460. Epub 2004 Aug 17.
Reprocessing dialysers is a common cost-saving practice in the USA. It began when patients were treated with bio-incompatible cellulosic membranes that were associated with medical complications, but has continued for economic reasons despite the current use of more biocompatible non-cellulosic membranes. A dialysis services and product provider using primarily its own non-cellulosic membranes recently embarked on a staged programme to stop reprocessing dialysers. Approximately a quarter of 71,000 patients had been switched from reuse to single use by July 1, 2001. The transition offered a unique opportunity to re-evaluate death risk associated with the reuse practice.
Patients were classified as reuse or single use as of July 1, 2001. Survival time measurements started on that date (Lag0) and at four 30 day intervals after it (Lag30, Lag60, Lag90 and Lag120). Thus, patients must have been treated in their reuse group after Lag0 for at least 30, 60, 90 or 120 days, respectively. Survival time was evaluated during 1 year following the lag date using the Cox method in unadjusted, case mix-adjusted and case mix plus other measure-adjusted models.
All analyses suggested favourable survival advantage among patients treated with single use dialysers. The differences were statistically significant at all lag times in the unadjusted models but became significant only at later lag times in the case mix- and case mix plus other measure-adjusted models. For example, single use/reuse hazard ratios in the case mix-adjusted models at Lag0-Lag120 were 0.96 (NS), 0.96 (NS), 0.94 (P = 0.02), 0.93 (P = 0.02) and 0.92 (P = 0.01), respectively.
A risk benefit appears associated with abandonment of the dialyser reuse practice, although the benefit may lag behind the change. In the USA, the relative risk burden associated with the reprocessing of dialysers may have changed over time with the evolution of clinical practice.
在美国，透析器再处理是一种常见的节省成本的做法。这种做法始于患者使用与医疗并发症相关的生物不相容性纤维素膜进行治疗之时，尽管目前使用的是生物相容性更好的非纤维素膜，但出于经济原因仍在继续。一家主要使用其自身非纤维素膜的透析服务和产品供应商最近启动了一项分阶段计划，以停止透析器再处理。到2001年7月1日，在71000名患者中约有四分之一已从复用改为一次性使用。这一转变为重新评估与复用做法相关的死亡风险提供了独特的机会。
截至2001年7月1日，将患者分为复用组或一次性使用组。生存时间测量从该日开始（Lag0），并在其后每隔30天进行一次（Lag30、Lag60、Lag90和Lag120）。因此，患者在Lag0之后必须在其复用组中分别接受至少30、60、90或120天的治疗。在滞后日期后的1年期间，使用Cox方法在未调整、病例组合调整和病例组合加其他测量调整模型中评估生存时间。
所有分析均表明，使用一次性透析器治疗的患者具有良好的生存优势。在未调整模型中，所有滞后时间的差异均具有统计学意义，但在病例组合调整和病例组合加其他测量调整模型中，仅在较晚的滞后时间差异才具有统计学意义。例如，在病例组合调整模型中，Lag0-Lag120时一次性使用/复用的风险比分别为0.96（无统计学意义）、0.96（无统计学意义）、0.94（P = 0.02）、0.93（P = 0.02）和0.92（P = 0.01）。
放弃透析器复用做法似乎存在风险效益关系，尽管效益可能在改变之后才显现。在美国，随着临床实践的演变，与透析器再处理相关的相对风险负担可能随时间发生了变化。
