Abstract. The goal of RMSTdesign is to make it easy to design clinical trials with the difference in restricted mean survival time as the primary endpoint. See Also The first thing to do is to use Surv() to build the standard survival object. The lung dataset is available from the survival package in R. The data contain subjects with advanced lung cancer from the North Central Cancer Treatment Group. The restricted mean is a measure of average survival from time 0 to a specified time point, and may be estimated as the area under the survival curve up to that point. Restricted mean survival time (RMST) is an underutilized estimand in time-to-event analyses. The restricted mean survival time (RMST) is a relatively new parameter proposed to improve the analysis of survival curves. Fundamental aspects of this approach are captured here; detailed overviews of the RMST methodology are provided by Uno and colleagues.16., 17. An R community blog edited by RStudio. The variable time records survival time; status indicates whether the patient’s death was observed (status = 1) or that survival time was censored (status = 0).Note that a “+” after the time in the print out of km indicates censoring. The number of observations, the number of events, the median survival with its confidence interval, and optionally the restricted mean survival (rmean) and its standard error, are printed. As opposed to the median, the RMST has the advantage of capturing the overall shape of the survival curve, including the so-called “right tail.” One limitation of RMST lies in the mathematical complexity of its calculation (model-dependent analysis). Restricted mean survival time analysis. Survival Analysis. Miller, Rupert G., Jr. (1981). time: Survival time in days; status: censoring status 1=censored, 2=dead; sex: Male=1 Female=2 New York:Wiley, p 71. Herein, we highlight its strengths by comparing time to (1) all-cause mortality and (2) initiation of antiretroviral therapy (ART) for HIV-infected persons who inject drugs (PWID) and persons who do not inject drugs. Methods for regression analysis of mean survival time and the related quantity, the restricted mean survival time, are reviewed and compared to a method based on pseudo-observations. Some variables we will use to demonstrate methods today include. The difference in restricted mean survival times (RMSTs) up to a pre‐specified time point is an alternative measure that offers a clinically meaningful interpretation. If there are multiple curves, there is one line of output for each. The RMST represents the area under the survival curve from time 0 to a specific follow-up time point; it is called restricted mean survival time because given X as the time until any event, the expectation of X (mean survival time) will be the area under the survival function (from 0 to infinity). This analytical approach utilizes the restricted mean survival time (RMST) or tau (τ)-year mean survival time as a summary measure. Regression models for survival data are often specified from the hazard function while classical regression analysis of quantitative outcomes focuses on the mean value (possibly after suitable transformations). In some recent papers published in clinical journals, the use of restricted mean survival time (RMST) or τ ‐year mean survival time is discussed as one of the alternative summary measures for the time‐to‐event outcome. We consider the design of such trials according to a wide range of possible survival distributions in the … References. Kaplan Meier Analysis. Several regression‐based methods exist to estimate an adjusted difference in RMSTs, but they digress from the model‐free method of taking the area under the survival function. We present strmst2, a new command to implement k-sample comparisons using the restricted mean survival time (RMST) as the summary measure of the survival-time distribution.Unlike model-based summary measures such as the hazard ratio, the validity of which relies on the adequacy of the proportionalhazards assumption, the measures based on the RMST (that is, the difference in RMST, …