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Re: st: Interval censored data in survival analysis


From   Steven Samuels <[email protected]>
To   [email protected]
Subject   Re: st: Interval censored data in survival analysis
Date   Fri, 30 Jan 2009 10:20:58 -0500


I thought I should point out the exact problems with John's second alternative. First, by putting all events at the end of the censoring interval, it will estimates of P(Y<t) will be less than the true values, for any t. Second, the added censored observations will inflate the denominators for risk calculations in prior intervals. This will greatly shrink the estimates of P(Y<t).

-Steve




On Jan 29, 2009, at 8:13 AM, John Stephenson wrote:

I am attempting to do a parametric survival analysis with interval censored data. However, I don't know if Stata can handle interval censoring. Does
anyone know how to do this using Stata? (I am working with release 9)

Alternatively, if it is not possible (or easy), two alternatives are:
1. find the midpoint of each interval and use that
2. assuming that each item of data is interval censored between time T1 and some later time T2, duplicate each item so that the same item appears both as a positive outcome at time T2 and as a right censored outcome at T1.

If anyone has any views on the accuracy and applicability of either of
these methods I'd be grateful to hear them.

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