Kaplan-Meier生存曲线与手动固定患者池下降率

时间:2015-09-08 03:46:28

标签: r ggplot2 survival-analysis

我创建了一个带有两条Kaplan-Meier生存曲线的图,以显示两种药物对患者生存的影响。该数据集包括41名患者,26名(A1-A26)接受了口服药物,15名(B1-B15)接种了疫苗。 x轴显示日期,y轴显示整个患者池的百分比。我只对绘制研究的0-400天感兴趣,这意味着将不会显示两个“口服”(A25,A26)和“疫苗”(B14,B15)的数据点。此外,我想绘制Kaplan-Meier曲线在患者死亡时下降1.45个单位(如数据栏“生存”中所示)。基于此,“口服”曲线将停留在62.32%,“疫苗”曲线停留在81.16%(不包括两个数据点,每个> 400天),因此y轴将从60%开始(而不是0%)。然而,目前,“口服”曲线下降26/100单位,“疫苗”曲线下降15/100单位,假设所有患者将在试验结束时死亡。因此,我有兴趣知道:

  1. 患者人数下降率是否可以固定在1.45单位
  2. 如何显示数据点持续超过400天(实际上没有将曲线扩展到那些数据点> 400天)和
  3. 我是否正确使用了对象'status'(即我给每个病人的状态为1)。
  4. 下面是一个可重现的示例数据集和我目前使用的代码。

    必需的套餐: 库(生存) 库(GGPLOT2)

    1. 加载可重现的数据

      structure(list(patient = structure(c(1L, 12L, 20L, 21L, 22L, 
      23L, 24L, 25L, 26L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 11L, 
      13L, 14L, 15L, 16L, 17L, 18L, 19L, 27L, 34L, 35L, 36L, 37L, 38L, 
      39L, 40L, 41L, 28L, 29L, 30L, 31L, 32L, 33L), .Label = c("A1", 
      "A10", "A11", "A12", "A13", "A14", "A15", "A16", "A17", "A18", 
      "A19", "A2", "A20", "A21", "A22", "A23", "A24", "A25", "A26", 
      "A3", "A4", "A5", "A6", "A7", "A8", "A9", "B1", "B10", "B11", 
      "B12", "B13", "B14", "B15", "B2", "B3", "B4", "B5", "B6", "B7", 
      "B8", "B9"), class = "factor"), survival = c(98.55, 97.1, 95.65, 
      94.2, 92.75, 91.3, 89.85, 88.4, 86.95, 85.5, 84.05, 82.6, 81.15, 
      79.7, 78.25, 76.8, 75.35, 73.9, 72.45, 71, 69.55, 68.1, 66.65, 
      65.2, 49.9, 57.97, 98.55, 97.1, 95.65, 94.2, 92.75, 91.3, 89.85, 
      88.4, 86.95, 85.5, 84.05, 82.6, 81.15, 67.6, 72), days = c(103L, 
      105L, 110L, 121L, 124L, 126L, 140L, 144L, 152L, 173L, 176L, 181L, 
      185L, 200L, 206L, 211L, 223L, 247L, 253L, 261L, 276L, 281L, 309L, 
      334L, 402L, 489L, 148L, 216L, 255L, 257L, 280L, 290L, 306L, 325L, 
      305L, 307L, 334L, 329L, 343L, 560L, 610L), treatment = structure(c(1L, 
      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
      2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("oral", "vaccine"
      ), class = "factor"), status = c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
      1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 
      1L, 1L)), .Names = c("patient", "survival", "days", "treatment", 
      "status"), class = "data.frame", row.names = c(NA, -41L))
      
    2. 创建一个Surv对象并估算数据的幸存者函数

      fit.test <- survfit(Surv(days, status == 1) ~ treatment, data=test, conf.int=FALSE)
      
    3. 运行功能ggsurv

    4. 剧情

      ggsurv(fit.test, lty.est = 1) + 
      geom_text(data = NULL, size=5.0, col = "red", x = 39.0, y = 0.23,  label = "oral") +
      geom_text(data = NULL, size=5.0, col = "blue", x = 30.5, y = 0.12, label = "vaccine") +
      
      scale_x_continuous(expand=c(0.01,0.01),
                   limits=c(0,400),
                   breaks=c(0,50,100,150,200,250,300,350,400),
                   labels=c("0","50","100","150","200","250","300","350","400")) +
      scale_y_continuous(expand=c(0.005,0.01),
                   limits=c(0,1.0),   
                   breaks=c(0,0.2,0.4,0.6,0.8,1),
                   labels=c("0","0.2","0.4","0.6","0.8","1.0")) +
      
      xlab("Time") +
      ylab("Survival") + 
      
      theme_bw() +
      theme(legend.position="none") +
      theme(axis.title.x = element_text(vjust=0.1,face="bold", size=16),
      axis.text.x = element_text(vjust=4, size=14))+ 
      theme(axis.title.y = element_text(angle=90, vjust=0.70, face="bold", size=18),
      axis.text.y = element_text(size=14)) +
      theme(panel.grid.minor=element_blank(), panel.grid.major=element_blank()) +
      theme(panel.border = element_rect(size=2, colour = "black", fill=NA, linetype=1)) +
      theme(plot.margin = unit(c(-0.9,0.4,0.28,0.0),"lines"))
      

1 个答案:

答案 0 :(得分:0)

创建survival对象会产生问题。您提供数据的方式看起来就像该组中的所有患者在口服489天后和疫苗接种610天后都经历过该事件。但是,您知道这只是数据的一部分,因为您可以获得剩余患者的百分比。您可以为组中最后一天没有经历过事件的患者添加行,并为其指定状态0.或者,您只需使用geom_step创建绘图而不使用ggsurv功能。

round(100/1.45)
test <- test[ ,c(1,3:5)]
extra_patients <- 
  data.frame(patient = c(paste('A', 27:69, sep = ''), 
                        paste('B', 16:69, sep = '')),
            days = rep(c(489, 610), c(43, 54)),
            treatment = rep(c('oral', 'vaccine'), c(43, 54)),
            status = 0)
 full_test <- rbind(test, extra_patients)
 library(survival)
 fit.test <- survfit(Surv(days, status == 1) ~ treatment, data=full_test, conf.int=FALSE)
 library(GGally)
 ggsurv(fit.test) + coord_cartesian(xlim = c(0,400))