Summary of a Survival Curve

DESCRIPTION:

Returns a list containing the survival curve, confidence limits for the curve, and other information.

USAGE:

summary.survfit(fit, times=<<see below>>, censored=F, scale=1)

REQUIRED ARGUMENTS:

fit
the result of a call to the survfit function.

OPTIONAL ARGUMENTS:

times
vector of times; the returned matrix will contain 1 row for each time. This must be in increasing order and missing values are not allowed. If censored=T, the default times vector contains all the unique times in fit, otherwise the default times vector uses only the event (death) times.
censored
logical value: if TRUE, the censoring times are included in the output. This is ignored if the times argument is present.
scale
numeric value to rescale the survival time, e.g., if the input data to survfit were in days, scale=365.25 would scale the output to years.

VALUE:

a list with the following components:
surv
the estimate of survival at time t+0.
time
the timepoints at which the curve has a step.
n.risk
the number of subjects at risk at time t-0 (but see the comments on weights in the survfit help file).
n.event
if the times argument is missing, then this column is the number of events that occurred at time t. Otherwise, it is the cumulative number of events that have occurred since the last time listed until time t+0.
std.err
the standard error of the survival value.
conf.int
level of confidence for the confidence intervals of survival.
lower CI
lower confidence limits for the curve.
upper CI
upper confidence limits for the curve.
strata
indicates stratification of curve estimation. If strata is not NULL, there are multiple curves in the result and the surv, time, n.risk , etc. vectors will contain multiple curves, pasted end to end. The levels of strata (a factor) are the labels for the curves.
call
the statement used to create the fit object.
na.action
passed through from fit, if present.

SEE ALSO:

, .

EXAMPLES:

summary(survfit(Surv(time, status) ~ group, data=leukemia))