clogit(survival)
clogit()所属R语言包:survival
Conditional logistic regression
条件Logistic回归分析
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Estimates a logistic regression model by maximising the conditional likelihood. Uses a model formula of the form case.status~exposure+strata(matched.set). The default is to use the exact conditional likelihood, a commonly used approximate conditional likelihood is provided for compatibility with older software.
logistic回归模型估计的条件的可能性最大化。使用模型公式的形式case.status~exposure+strata(matched.set)。默认情况下使用的确切条件的可能性,一种常用的近似条件的可能性是与旧版本软件的兼容性。
用法----------Usage----------
clogit(formula, data, weights, subset, na.action,
method=c("exact", "approximate", "efron", "breslow"),
...)
参数----------Arguments----------
参数:formula
Model formula
模型公式
参数:data
data frame
数据框
参数:weights
optional, names the variable containing case weights
可选的,命名变量的收纳箱重量
参数:subset
optional, subset the data
可选的子集的数据
参数:na.action
optional na.action argument. By default the global option na.action is used.
可选na.action的说法。默认情况下,全局选项“na.action使用。
参数:method
use the correct (exact) calculation in the conditional likelihood or one of the approximations
使用正确的在有条件的似然率计算(精确的)或1的近似值
参数:...
optional arguments, which will be passed to coxph.control
可选的参数,这些参数将被传递给coxph.control
Details
详细信息----------Details----------
A stratified Cox model with time=constant, status of 1=case 0=control, and using the exact partial likelihood has the same likelihood formula as a conditional logistic regression. The clogit routine creates the necessary dummy variable of times (all 1) and then calls coxph.
随着时间的推移一个分层的Cox比例风险模型=常数,状态= 1的情况下,0 =控制,并采用精确的局部似然作为条件Logistic回归公式具有相同的可能性。的clogit程序创建所需的虚拟变量倍(所有1),,然后调用coxph。
The computation of the exact partial likelihood can be very slow, however. If a particular strata had say 10 events out of 20 subjects we have to add up a denominator that involves all possible ways of choosing 10 out of 20, which is 20!/(10! 10!) = 184756 terms. Gail et al describe a fast recursion method, which largely ameleorates this; it was incorporated into version 2.36-11 of the survival package. (Most of the time conditional logistic modeling is applied data with 1 case + k controls per set, however, which involves choosing 1 out of k and the computational issue above does not arise.) The 'appoximate' option maps to the Breslow approximation for historical reasons.
计算精确的局部似然可以是非常缓慢的,但是。如果一个特定的阶层已经说了10个项目的20个科目,我们添加了一个分母,涉及所有可能的方式选择10 20,20 /(10 10)= 184756条款。盖尔等人描述了一种快速递归的方法,这在很大程度上ameleorates此,它被纳入的生存包的版本2.36-11。 (大部分的时间条件Logistic模型应用的数据有1例+ K控制每套,但是,这涉及到选择1 k和上面的计算问题不会出现。)appoximate的“选项映射到布瑞斯罗夫近似由于历史的原因。
It is not clear how case weights should be handled. For instance if there are two deaths in a strata, one with weight=1 and one with weight=2, should the likelihood calculation consider all subsets of size 2 or all subsets of size 3? Consequently, case weights are ignored by the routine.
目前尚不清楚的情况下,权重应该如何处理。例如,如果有两人死亡,一个阶层,一个带权重= 1,一个体重= 2,计算的可能性应该考虑大小为2或所有子集的所有子集的大小为3?因此,情况权重将被忽略的常规。
值----------Value----------
An object of class "clogit", which is a wrapper for a "coxph" object.
类的一个对象"clogit",这是一个包装的"coxph"对象。
参考文献----------References----------
calculations for matched case-control studies and survival studies with tied death times. Biometrika 68:703-707, 1980.
(作者)----------Author(s)----------
Thomas Lumley
参见----------See Also----------
strata,coxph,glm
strata,coxph,glm
实例----------Examples----------
## Not run: clogit(case ~ spontaneous + induced + strata(stratum), data=infert)[#未运行:clogit(的情况下自发+引起的地层(层),数据infert)]
# A multinomial response recoded to use clogit[多项式响应重新编码,使用clogit]
# The revised data set has one copy per possible outcome level, with new[修订后的数据集有一个副本每个可能的结果水平,与新]
# variable tocc = target occupation for this copy, and case = whether[变量TOCC这个副本的目标职业和案例=是否]
# that is the actual outcome for each subject.[这是每个科目的实际结果。]
# See the catspec package for more details.[有关详细信息,请参阅catspec包。]
resp <- levels(logan$occupation)
n <- nrow(logan)
indx <- rep(1:n, length(resp))
logan2 <- data.frame(logan[indx,],
id = indx,
tocc = factor(rep(resp, each=n)))
logan2$case <- (logan2$occupation == logan2$tocc)
clogit(case ~ tocc + tocc:education + strata(id), logan2)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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