[R] exact 95% confidence intervals

[Peter Dalgaard]

Frank E Harrell Jr <f.harrell at vanderbilt.edu> writes:

> Peter Dalgaard wrote:
> > "XinMeng" <xmeng at capitalbio.com> writes:
> >
> >> Hello sir:
> >
> >> As to the 2*2 table format for reporting results comparing a new
> >> test to true diagnosis,when I got the sensitivity and
> >> specificity,how can I calculate the exact 95% confidence intervals
> >> (based on the binomial distribution) for sensitivity and specificity
> >> via R?
> > Just run binom.test on the data from each column (or row, depending
> > on
> > which way you turn the tables).
> >
> 
> But beware of exact binomial intervals - they are often not very
> accurate.  Wilson and other intervals are generally better.  For
> example see the binconf function in the Hmisc package.

I suppose that by "accurate" you mean that they are generally better
at getting the coverage rate right? 

The "exact" intervals are strictly conservative, but at least
predictably so. The whole thing is largely a matter of taste to my
mind, but I know that other people (notably Alan Agresti) have
stronger opinions.

(People taking an interest in this may want to have a look at
http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval )

-- 
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