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