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? 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 ) -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ 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.
