Hi Everyone
I may be working with a data set that has the following
structure and will need to develop a distance measure. I have not had
time to think carefully about it but am hoping someone might have already
worked with data like this.
Patients present to the doctor with a disease and it is
unknown which of four drugs they will respond to (the goal of this project is
to improve the ability to predict and be able to give the correct drug first).
MD’s treat these patients empirically – give them drug A and
see if they respond, if not give them drug B and see if they respond, etc.
We assume a patient either responds or does not, and that
there is no carry over or order of drug effect (i.e., if you respond to drug B
it is irrelevant if you had already had drug A). I also assume there is
no set order on which drugs are given first.
The data for each patient will be a vector of 0’s for
non response and a 1 for response, with the number of 0’s dependent on how
many drugs were given empirically before a response occurred.
How do we calculate a pair wise distance matrix between
pairs of patients with this data?
Thank
you.
Bill
Shannon, PhD
Associate
Professor of Biostatistics in Medicine
Washington
University School of Medicine
St. Louis, MO
314-454-8356