Adjusted Nelson-Aalen estimates with retrospective matching
Adjusted Nelson-Aalen estimates with retrospective matching
复制标题
DOI：
10.1198/016214502753479383
复制
发表时间：
2002-03-01
影响因子：
3.7
通讯作者：
Sasieni, P
中科院分区：
文献类型：
--
作者：
Winnett, A;Sasieni, P
在某些情况下，随机试验是不可能的，但对两组或更多组的存活率进行正式比较仍然是可取的。虽然不能替代随机化，但将配对病例对照设计应用于生存研究可能会将潜在的偏倚降至最低。通过根据预后变量进行匹配或分层，并对每个个体进行加权，以使各治疗组的地层分布相同，可以获得每个治疗组的可比估计。在这里，我们发展了加权Nelson-Aalen估计和相应的生存估计。当数据接近匹配时，应将地层效应视为随机的，从而导致额外的方差分量，标准的渐近结果不适用。我们推导了一个方差估计，并证明了该估计渐近收敛于一个高斯过程。模拟结果表明，在中等大小的样本中，渐近结果是一个很好的近似，需要注意的是，忽略异质性将导致对方差的低估。在一项临床研究中提出了一个应用，其中获得了接受标准治疗的患者的数据，用于与接受新治疗的患者进行比较，并通过回顾匹配来获得可比较的估计。
In certain situations, randomized trials are not possible, but formal comparison of survival in two or more groups is still desirable. Although no substitute for randomization, application of the matched case-control design to survival studies may minimize the potential bias. Comparable estimates for each treatment group can be obtained by matching or stratifying according to prognostic variables, and weighting each individual to make stratum distributions the same over the treatment groups. Here we develop a weighted Nelson-Aalen estimator and a corresponding survival estimator. When data are closely matched, the stratum effects should be considered as random, leading to additional variance components, and standard asymptotic results do not apply. We derive a variance estimator and show that, asymptotically, the estimator converges to a Gaussian process. Simulations show that the asymptotic results are a good approximation in moderate-sized samples, It should be noted that ignoring the heterogeneity will lead to underestimation of the variance. An application is presented in a clinical study where data on patients receiving standard treatments are obtained for comparison with patients receiving a novel treatment, with retrospective matching to obtain comparable estimates.