Please forgive my initial post. I don't believe I defined the problem adequately. My treatment arm is prospectively enrolling with enrollment to be completed in two years. My control arm has multiple, historical studies with aggregate data extracted from study reports. I have a reference from Statistics in Medicine, 2008 titled "Meta-analysis of summary survival curve data." The article details a method using a multivariate random-effects framework with SAS Proc MIXED. The method makes sense, but I would appreciate any feedback from anyone who has implemented this or any other method for time point specific comparisons where control groups have only summary data.
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Kathy Warner
Consultant Services
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Original Message:
Sent: 10-17-2012 18:53
From: Lance Heilbrun
Subject: Appropriate test for Tumor Recurrence With Historical Control
Kathy:
I presume that you have an estimate of the 5-yr and the 10-yr recurrence rates in your historical control patients. In other words, I presume that you do have what might be considered as population reference values.
So, you have a 1-sample design and you wish to size your new study to test your future estimates of the 5-yr and the 10-yr recurrence rates against their respective population reference values.
If all that is correct, then you can determine the required sample size (separately) for each endpoint to be tested using the "One Arm Survival" program at the following website:
http://www.crab.org/Resources/StatisticalTools.aspx
They cite a methodolgy reference there too, which you can cite in your stat'l design writeup if you need to.
Please note that the Normal theory assumption for this program yields smaller N's than will result from using the related "One Arm Nonparametric Survival" program also available there.
I hope the above suggestion proves both on target for your study design problem, and helpful to solving it. Beware that you are embarking on a study that will require long-term follow-up.
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Lance Heilbrun
Karmanos Cancer Institute Biostatistics Core
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Original Message:
Sent: 10-17-2012 17:09
From: Kathy Warner
Subject: Appropriate test for Tumor Recurrence With Historical Control
It is one primary endpoint evaluated at two time points.
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Kathy Warner
Consultant Services
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