 |
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]
Re: st: RE: Quantile question
On 2 Mar 2008, at 17:01, Nick Cox wrote:
I don't understand what you understand by quantile here. In
particular,
what is a "1-quantile" increase?
Sorry if that wasn't clear. Perhaps an example would help. I was
involved in looking at the effect of a number of measures of the
patient's response to illness as predictors of depression - work and
social adjustment, symptom frequency, symptom bother, and so on.
These were measured using standardised scales, but each scale had its
own theoretical range, its own empirical score distribution and, most
important, each scale was measured in arbitrary units.
It was useful for the reader to be able to see the odds ratios (and
confidence intervals) associated with a 1-decile increase in each of
these predictors, as it gave them a way of comparing their effects
and of judging their practical importance as well as their
statistical significance.
There are times, then, when quantiles do not lose information but
increase it, by converting unfamiliar and arbitrary measurement
scales to a definable measurement unit.
P Before printing, think about the environment
=================================
Ronan Conroy
[email protected]
Royal College of Surgeons in Ireland
Epidemiology Department,
120 St Stephen's Green, Dublin 2, Ireland
+353 (0)1 402 2431
+353 (0)87 799 97 95
http://www.flickr.com/photos/ronanconroy/sets/72157601895416740/
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/