I have an medical test which has been repeatedly administered to patients over time that I would like to analyze.
The tests results are ordinal (Neg, Scanty, 1, 2, and 3).
The testing schedule was irregular - daily for the first two weeks, weekly for the next two weeks and then monthly for a total of six months.
I have data from 25 patients.
An example would look like this:
I have used Mann-Kendall & Theil-Sen Slopes to analyze non-parametric trend data. This seems somewhat correct because they are rank tests.
Is this appropriate with ordinal data?
Additionally, I would like to see if some of the clinical data regarding the patients is associated with their outcome and I am not at all confident that either of those tests will assist me in that.
If not, are there suggestions for alternative trend detection?