The inverse hyperbolic sine transformation might be useful in this
situation.
Scott
> -----Original Message-----
> From: [email protected] [mailto:owner-
> [email protected]] On Behalf Of Daniel Waxman
> Sent: Monday, June 06, 2005 6:17 AM
> To: [email protected]
> Subject: RE: st: how to deal with censoring at zero (a lot of zeroes) for
> a laboratory re
>
> Maarten, Kevin,
>
> Thank you very much for your replies. So for now I am just going give up
> trying to make distributional assumptions and to drop the half of the
> observations which are zero or non-detectable prior to log transforming
> the
> predictor and to creating the logistic model. In fact, whether I do this
> or
> change the zero to half of the lowest detectable value (i.e. .005) doesn't
> have much of an effect on the logistic odds ratio.
>
> If anybody has any objections to this (or sees how a statistical reviewer
> for a medical journal might have objections), please let me know.
>
> Daniel
>
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