Peter Dalgaard wrote: > Frank E Harrell Jr <[EMAIL PROTECTED]> writes: > >> Peter Dalgaard wrote: >>> "XinMeng" <[EMAIL PROTECTED]> 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?
Yes > > 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. I tend to side with Agresti, and emphasize the expected absolute error in confidence coverage. > > (People taking an interest in this may want to have a look at > http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval ) nice to know! Frank ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
