--- On Wed, 24/6/09, Fred Wolfe wrote:
> I wonder if anyone on the Stata list
> may be able to suggest a method
> to solve this problem using Stata.
>
> I am trying do determine the
> prevalence and confidence intervals
> of a side effect to a treatment.
> Several thousand treated subjects
> have taken a drug. They are asked if
> they had a specific side effect to the
> drug. Those that say no are classified
> as being side effect negative. Those
> that say yes are contacted to obtain
> the name of their physician, and the
> physician is asked to verify the side
> effect. Only about one third of
> physicians can be contacted, and from
> them we can get the proportion positive
> and negative for the side effect. Assume
> that the non-responses are unrelated to
> the outcome. I can extrapolate from the
> responding physicians to the non-responding
> physicians and calculate an overall
> prevalence of the side effect. What I
> would like to do is to obtain confidence
> intervals for this prevalence estimate,
> but I do not see an easy way to do this in
> Stata. I wonder if anyone might suggest a
> solution.
Sounds like a problem for Multiple Imputation,
though 2/3 missing may be pushing it a bit.
This is implemented in Stata as -ice-, type
in Stata -findit ice-, to findit and to find
several papers on it in the Stata Journal.
-- Maarten
-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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