Nouta Klaas-Auke, Pijls Bart G, Fiocco Marta, Keurentjes J Christiaan, Nelissen Rob G H H
Department of Orthopaedics, Leiden University Medical Center, Postal code J11R, P.O. Box 9600, 2300 RC, Leiden, The Netherlands,
Int Orthop. 2014 May;38(5):953-9. doi: 10.1007/s00264-013-2193-x. Epub 2013 Dec 5.
The aim of this study was to develop a more accurate method to deal with patients lost to follow-up based on the competing risks approach.
A cohort of 112 patients who received 143 primary cemented total knee arthroplasties forms the basis for this study. Follow-up was up to 25 years. The new method for dealing with lost to follow-up accounts for competing events (i.e. death and failure of a prosthesis) using the cumulative incidence estimator and estimates time to event for patients lost to follow-up using national demographic registries. The results of this new method were compared with the worst case scenario estimated by Kaplan-Meier.
Six different situations were identified covering all possible situations in long-term follow-up for total knee arthroplasty. The new method--considering all patients lost to follow-up as revised--showed a twofold reduction in revision rate compared to the traditional worst case scenario using Kaplan-Meier.
Lost to follow-up should be prevented whenever possible, but this may be unavoidable for long-term follow-up studies. In situations where lost to follow-up does occur, the new proposed method offers an efficient and valid approach to deal with this problem.
本研究的目的是基于竞争风险方法开发一种更准确的方法来处理失访患者。
一组接受了143例初次骨水泥全膝关节置换术的112名患者构成了本研究的基础。随访时间长达25年。处理失访的新方法使用累积发病率估计器来考虑竞争事件(即死亡和假体失败),并使用国家人口登记处估计失访患者的事件发生时间。将这种新方法的结果与Kaplan-Meier估计的最坏情况进行比较。
确定了六种不同情况,涵盖了全膝关节置换术长期随访中的所有可能情况。新方法——将所有失访患者视为经过修订——与使用Kaplan-Meier的传统最坏情况相比,翻修率降低了两倍。
应尽可能防止失访,但对于长期随访研究而言,这可能不可避免。在确实发生失访的情况下,新提出的方法提供了一种有效且合理的方法来处理这个问题。