I would be grateful for advice about the following problem. It's not directly R-related, but I'm hoping that R will help me analyse the following data.
I have a table which indicates the progression of a certain age-related disease. At a certain point in time, a population was sampled; and I have measurements for the age of each individual, and their disease stage. (Disease stage is an ordered factor, none<A<B<C<D.) I hypothesize that the rate of disease-onset depends on age, but that (once the disease has started) its rate of progression depends on the current disease stage and not on age. I would like to plot the data in a sensible way, to let me see if this hypothesis is reasonable, and to let me explore possible functional forms for the two rates. I can see how to plot the rate of disease onset. I could, for example, plot for each age the fraction of people who have acquired the disease by that age. But I don't know how to visualize the rate of disease progression. All suggestions (especially pointers to relevant literature or R packages) gratefully received! Damon. ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
