R : 在 RandomForestSRC 中擬合具有時變協變量的生存樹

Question

在包 LTRCtrees 中，可以按照以下示例將決策樹擬合為 Surv 函數的特殊格式：Surv(time, time2, event)

set.seed(0)
library(survival)
library(LTRCtrees)
## Create the start-stop-event triplet needed for coxph and LTRC trees
first <- with(pbcseq, c(TRUE, diff(id) !=0)) #first id for each subject
last <- c(first[-1], TRUE) #last id
time1 <- with(pbcseq, ifelse(first, 0, day))
time2 <- with(pbcseq, ifelse(last, futime, c(day[-1], 0)))
event <- with(pbcseq, ifelse(last, status, 0))
event <- 1*(event==2)

pbcseq$time1 <- time1
pbcseq$time2 <- time2
pbcseq$event <-  event

## Fit the Cox model and LTRC trees with time-varying covariates
fit.cox <- coxph(Surv(time1, time2, event) ~ age + sex + log(bili), pbcseq)
LTRCIT.fit <- LTRCIT(Surv(time1, time2, event) ~ age + sex + log(bili), pbcseq)
LTRCART.fit <- LTRCART(Surv(time1, time2, event) ~ age + sex + log(bili), pbcseq)

是否可以使用 RandomForestSRC 庫在隨機森林上使用相同的功能

library(randomForestSRC)
RF.fit <- rfsrc(Surv(time1, time2, event) ~ age + sex + log(bili), data=pbcseq, nsplit = 3, ntree = 100, importance = TRUE)

這會產生一個錯誤：

Error in parseFormula(formula, data, ytry) : 
  Survival formula incorrectly specified.

Answer 1

Wongvibulsin、Wu 和 Zeger（2019 年）的這篇論文擴展了 randomForestSRC 包以處理 TVC，但您可能需要聯系作者以獲取任何相關代碼。