Hi,

Apologies if this is a silly question -- I am just now learning how to use
some of the basic functions in
the rms library.

I have been using

     foo.dist <- datadist(foo.frame)
     options(datadist='foo.dist')
     lrm.model <- lrm(binary.outcome ~ rcs(contin.var,5)+categ.var, data =
foo.frame, x=TRUE)
     lrm.predict <- predict(lrm.model, type = "fitted")

to obtain the predicted probabilities from a logistic regression model, but
now I need the associated 95%
prediction intervals associated with these predicted probabilities.  I've
read the examples in the ?lrm
help page, and from the information about "predict" from
http://cran.r-project.org/web/packages/rms/rms.pdf
I have tried

     predict(lrm.model, conf.int = 0.95, conf.type = c("individual"))

but I get the error message

     Error in predictrms(object, ..., type = type, se.fit = se.fit) :
        conf.type="individual" requires that fit be from ols

>From the same PDF, I have read the "predict.lrm" pages and was not able to
figure out how to get
prediction intervals.



Many thanks in advance for some help,

    David

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