Calculates restricted mean survival time with treatment group comparisons.
Usage
rmst_analysis(
data,
time_var,
event_var,
trt_var,
tau,
conf_level = 0.95,
reference_group = NULL
)Arguments
- data
A data frame containing survival data
- time_var
Character. Name of the time variable
- event_var
Character. Name of the event indicator variable (1=event, 0=censored)
- trt_var
Character. Name of the treatment variable
- tau
Numeric. Time restriction for RMST calculation
- conf_level
Numeric. Confidence level for intervals (default: 0.95)
- reference_group
Character. Reference group for treatment comparison. If NULL, uses first level of treatment variable.
Details
The restricted mean survival time (RMST) is defined as:
RMST(tau) = E[min(T, tau)] = integral from 0 to tau of S(t) dt
where T is the survival time and S(t) is the survival function.
RMST is estimated using the Kaplan-Meier estimator:
RMST(tau) = tau - integral from 0 to tau of F(t) dt
= sum_i (t_i - t_i-1) * S(t_i-1)
where the integral is restricted to [0, tau].
References
Uno, H. et al. (2014). Moving beyond the hazard ratio in quantifying the between-group difference in survival analysis. Journal of Clinical Oncology, 32(22), 2380-2385.
Examples
if (FALSE) { # \dontrun{
# Basic RMST analysis
result <- rmst_analysis(
data = survival_data,
time_var = "time",
event_var = "status",
trt_var = "TRT01P",
tau = 12
)
# With custom confidence level
result <- rmst_analysis(
data = survival_data,
time_var = "time",
event_var = "status",
trt_var = "TRT01P",
tau = 24,
conf_level = 0.90
)
} # }