On Jun 4, 2011, at 11:41 AM, zhu yao wrote:
Dear UseRs:
Recently, I have read an article regarding the association between
age and
lymph node metastases.
http://jco.ascopubs.org/content/27/18/2931.long
In statistical analysis, the authors stated "Because a nonlinear
relationship between age and lymph node involvement was expected
based on
existing literature, lymph node involvement was also regressed on
age using
nonparametric logistic regression based on locally weighted
scatterplot
smoothing (lowess)."
<http://jco.ascopubs.org/content/27/18/2931.long#ref-11>
Could someone explain nonparametric logistic regression based on
locally
weighted scatterplot smoothing (lowess)?
Or it is nonparametric regression based on locally weighted
scatterplot
smoothing (lowess)
One can use a logistic link and a local likelihood. Loader describes
the advantages of such a strategy and shows a worked example in pages
60-65 of her text "Local Regression and Likelihood". But there is no
apparent R content in this question (and the authors of the above
paper said they used SAS) so this very much off-topic for this list.
You really should start such requests for explication by addressing
the authors of the paper. Two other web-based statistical sites for
general or medical statistics questions can be found at the
GoogleGroups MedStats group and http://stats.stackexchange.com/ .
--
David Winsemius, MD
West Hartford, CT
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