Survreg(), Surv() and interval-censored data
On Mon, 13 Feb 2006, Stephen Richards wrote:
Can survreg() handle interval-censored data like the documentation
says? I ask because the command:
survreg(Surv(start, stop, event) ~ 1, data = heart)
fails with the error message
Invalid survival type
yet the documentation for Surv() states:
"Presently, the only methods allowing interval censored data are
the parametric models computed by 'survreg'"
Any pointers as to what I'm missing?
You are specifying left-truncated, right-censored data, not interval-censored. You need the type= argument, eg
Surv(c(1,1,NA,3),c(2,NA,2,3),type="interval2")
[1] [1, 2] 1+ 2- 3 specifies interval censoring at [1,2], right-censoring at 1, left-censoring at 2, and an observed event at 3. -thomas