Message-ID: <Pine.LNX.4.64.0602151255320.20737@homer24.u.washington.edu>
Date: 2006-02-15T20:58:26Z
From: Thomas Lumley
Subject: Survreg(), Surv() and interval-censored data
In-Reply-To: <f301bda0602130845n3520c139k@mail.gmail.com>
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