help strmst2

Title

strmst2 -- Comparing restricted mean survival time

Syntax

strmst2
groupvar
[if] [in]
[, tau(#) covariates(varlist) level(#) reference(#) rmtl]

Description

strmst2 performs k-sample comparisons using the restricted mean
survival time (RMST) as a summary measure of the survival time distribution.
The comparison will be performed by groupvar, where groupvar is a
numeric categorical variable (with 0 typically indicating subjects in the control
group and 1 typically indicating subjects in the active treatment group).
Three kinds of between-group constrast metrics (i.e. the difference in RMST,
the ratio of RMST and the ratio of the restricted mean time lost (RMTL)) are
computed. It performs an ANCOVA-type covariate adjustment as well as unadjusted
analyses for those measures. The command presumes that the data have been
declared to be survival-time data using the stset command.

Options

tau(#) A scalar value to specify the truncation time point
for the RMST calculation. Tau needs to be smaller than the minimum of the
largest observed time (either event or censor) in each of the groups. When
tau is not specified, the default value (i.e. the minimum of the largest
observed event time in each of the groups) is used.

covariates(varlist) This specifies covariates to be used for the
adjusted analyses. When covariates is not specified, unadjusted analyses are
performed. When covariates is specified, the ANOCVA-type adjusted analyses are
performed using those variables passed as covariates. This can be one variable
or more than one variable.

level(#) set confidence level; default is level(95)

reference(#) set reference category; default is the smallest value

rmtl Display between-group contrasts for the ratio of the restricted
mean time lost (RMTL), in addition to the metrics for the restricted mean survival time
(RMST). The default is to show between-group contrasts only for the RMST.

by is allowed with strmst2; see [D] by.

Examples

. strmst2 treatment, tau(10)

. strmst2 treatment, tau(10) covariates(age bili albumin)

. strmst2 treatment, tau(10) covariates(age bili albumin) reference(2)

Authors

Angel Cronin

Dana-Farber Cancer Institute

angelm_cronin at dfci.harvard.edu

Lu Tian

Stanford University

lutian at stanford.edu

Hajime Uno

Dana-Farber Cancer Institute

huno at jimmy.harvard.edu

Also see

Uno H, Claggett B, Tian L, Inoue E, Gallo P, Miyata T, Schrag D,
Takeuchi M, Uyama Y, Zhao L, Skali H, Solomon S, Jacobus S, Hughes M, Packer M,
Wei LJ. Moving beyond the hazard ratio in quantifying the between-group
difference in survival analysis. Journal of clinical Oncology 2014, 32, 2380-2385.

Tian L, Zhao L, Wei LJ. Predicting the restricted mean event time with
the subject's baseline covariates in survival analysis. Biostatistics 2014, 15, 222-233.