GTSG

0th

Percentile

Gastrointestinal Tumor Study Group

A randomized clinical trial in gastric cancer.

Keywords
datasets
Usage
GTSG
Details

A clinical trial comparing chemotherapy alone versus a combination of chemotherapy and radiation therapy in the treatment of locally advanced, nonresectable gastric carcinoma.

Note

There is substantial separation between the estimated survival distributions at 8 to 10 months, but by month 26 the distributions intersect.

Format

A data frame with 90 observations on 3 variables.

time

survival time (days).

event

status indicator for time: 0 for right-censored observations and 1 otherwise.

group

a factor with levels "Chemotherapy+Radiation" and "Chemotherapy".

References

Moreau, T., Maccario, J., Lellouch, J. and Huber, C. (1992). Weighted log rank statistics for comparing two distributions. Biometrika 79(1), 195--198. 10.1093/biomet/79.1.195

Shen, W. and Le, C. T. (2000). Linear rank tests for censored survival data. Communications in Statistics -- Simulation and Computation 29(1), 21--36. 10.1080/03610910008813599

Tubert-Bitter, P., Kramar, A., Chal<U+00E9>, J. J. and Moureau, T. (1994). Linear rank tests for comparing survival in two groups with crossing hazards. Computational Statistics & Data Analysis 18(5), 547--559. 10.1016/0167-9473(94)90084-1

Aliases
  • GTSG
Examples
# NOT RUN {
## Plot Kaplan-Meier estimates
plot(survfit(Surv(time / (365.25 / 12), event) ~ group, data = GTSG),
     lty = 1:2, ylab = "% Survival", xlab = "Survival Time in Months")
legend("topright", lty = 1:2,
       c("Chemotherapy+Radiation", "Chemotherapy"), bty = "n")

## Asymptotic logrank test
logrank_test(Surv(time, event) ~ group, data = GTSG)

## Asymptotic Prentice test
logrank_test(Surv(time, event) ~ group, data = GTSG, type = "Prentice")

## Asymptotic test against Weibull-type alternatives (Moreau et al., 1992)
moreau_weight <- function(time, n.risk, n.event)
    1 + log(-log(cumprod(n.risk / (n.risk + n.event))))

independence_test(Surv(time, event) ~ group, data = GTSG,
                  ytrafo = function(data)
                      trafo(data, surv_trafo = function(y)
                          logrank_trafo(y, weight = moreau_weight)))

## Asymptotic test against crossing-curve alternatives (Shen and Le, 2000)
shen_trafo <- function(x)
    ansari_trafo(logrank_trafo(x, type = "Prentice"))

independence_test(Surv(time, event) ~ group, data = GTSG,
                  ytrafo = function(data)
                      trafo(data, surv_trafo = shen_trafo))
# }
Documentation reproduced from package coin, version 1.3-1, License: GPL-2

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