Puzzler1 < Main < Vanderbilt Biostatistics Wiki

---+ Binary Response, Three Potential Predictors, Independent Observations
In a hypothetical study, a sample of 500 subjects had three potential predictors measured: age, sex, and systolic blood pressure, and a diagnosis of a certain disease (present/absent) was made.  There is assumed to be no interaction between age and blood pressure.  The relationship between continuous variables and the probability of disease is smooth.  The data are found in the attachments below.  To read the dataset into R you can run save the =.rda= file to a temporary area, then =load('prob1.rda')= which will create a data frame =d= in your workspace (search position 1).  Alternatively, you can load the file ready for analysis directly from the WWW using =loadURL('http://biostat.mc.vanderbilt.edu/twiki/pub/Main/Puzzler1/prob1.rda')=.

Find a model that fits these data reasonably well.  A _smooth relationship_ means that the function relating either age or blood pressure to the probability of disease, holding the other predictors constant, has at least two orders of continuity, in other words, has no gaps or corners.

-- Main.FrankHarrell - 09 May 2004; Modified 17 May 2004

Topic attachments
I	Attachment	Action	Size	Date	Who	Comment
csv	prob1.csv	manage	14.2 K	09 May 2004 - 10:31	FrankHarrell	Comma separated file
rda	prob1.rda	manage	9.5 K	09 May 2004 - 10:30	FrankHarrell	R data file created with save(..., compress=TRUE)

This topic: Main > WebHome > CE > Puzzlers > Puzzler1
Topic revision: 22 Jul 2004, DalePlummer (raw view)

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