msSurv (version 1.2-2)

SOPt: State Occupation Probability at Time t

Description

This function displays the state occupation probability at time t and then prints it. The function also displays the corresponding variance if the user specifies.

Usage

SOPt(object, t="last", deci=4, covar=FALSE)

Arguments

object

A msSurv object.

t

The time at which we find the state occupation probabilities. Default is "last" which is the highest (or "last") event time.

deci

Numeric argument specifying number of decimal places for estimates. Default is 4.

covar

Logical argument to determine if variance is reported. Default is FALSE.

Value

Returned invisibly:

SOPt

The state occupation probability at time t.

var.sop

The variance of the state occupation probabilities at time t (if covar==TRUE).

Details

Displays the state occupation probabilities and corresponding variance for all states in the multistate model.

References

Nicole Ferguson, Somnath Datta, Guy Brock (2012). msSurv: An R Package for Nonparametric Estimation of Multistate Models. Journal of Statistical Software, 50(14), 1-24. URL http://www.jstatsoft.org/v50/i14/.

Datta, S. and Satten G.A. (2001). Validity of the Aalen-Johansen estimators of stage occupation probabilities and Nelson-Aalen estimators of integrated transition hazards for non-Markov models. Statistics and Probability Letters, 55(4): 403-411. Datta S, Satten GA (2002). Estimation of Integrated Transition Hazards and Stage Occupation Probabilities for Non-Markov Systems under Dependent Censoring. Biometrics, 58(4), 792-802.

See Also

msSurv

Examples

## Row elements of data 
p1 <- c(1,0,0.21,1,3)
p2 <- c(2,0,0.799,1,2)
p22 <- c(2,0.799,1.577,2,3)
p3 <- c(3,0,0.199,1,0)

## Combining data into a matrix
ex1 <- rbind(p1,p2,p22,p3)
colnames(ex1) <- c("id", "start", "stop", "start.stage", "end.stage")
ex1 <- data.frame(id=ex1[,1], start=ex1[,2], stop=ex1[,3],
                  start.stage=ex1[,4], end.stage=ex1[,5])


## Inputting nodes & edges of the tree structure
Nodes <- c("1","2","3") # states in MSM
Edges <- list("1"=list(edges=c("2","3")),"2"=list(edges=c("3")),
           "3"=list(edges=NULL)) ## allowed transitions between states
                                 ## edges=NULL implies terminal node

## Specifying tree
treeobj <- new("graphNEL", nodes=Nodes, edgeL=Edges,
                edgemode="directed")

## Running msSurv
ans1 <- msSurv(ex1,treeobj)
SOPt(ans1, t=2.5)