[R] nonparametric logistic regression based on locally weighted scatterplot smoothing (lowess)

[David Winsemius]

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