survMisc (version 0.2)

mean.Surv: Mean for Surv object

Description

Mean for Surv object

Usage

## S3 method for class 'Surv':
mean(x, alpha = 0.05, method = "Efron",
    tEnd = "", by = 1, dfm = FALSE, ...)

Arguments

x

A Surv object

alpha

Significance level $\alpha$

method

If the last observation is censored at time $t_k$, one of the following values for $\hat{S}$, the Kaplan-Meier estimate of survival time from then until tEnd is used: [object Object],[object Object],.,[object Object]

tEnd

If the last observation is censored at time $t_k$, an estimate of $\hat{S}$ will be generated from $t_k$ to tEnd. If tEnd="" a value of $2 \times t_{max}$, twice the longest time recorded, is used.

by

Increments (units of time) between $t_k$ and tEnd

dfm

If TRUE, will return the data frame used to calculate the statistics

...

Additional arguments

Value

• A list with the following elements:
• mean
  Mean of the Surv object
• variance
  The variance
• CI
  The confidence level (from $alpha$ above)
• upper
  Upper value for confidence interval
• lower
  Lower value for the confidence interval
• If the last observation is censored at time $t_k$, two values are returned, one calculated up to $t_k$, the other to tEnd.

References

Gill RD 1980 Censoring and Stochastic Integrals. Statistica Neerlandica 34(124).

Examples

data(bmt, package="KMsurv")
b1 <- bmt[bmt$group==1, ] # ALL patients
s1 <- Surv(time=b1$t2, event=b1$d3)
mean(s1)
s1 <- Surv(time=c(6,14,21,44,62),event=c(1,1,0,1,1))
mean(s1)
s2 <- Surv(time=c(6,14,21,44,62),event=c(1,1,0,1,0))
mean(s1)