I am attempting to run statistics in the following scenario:
I have a list of hospital visits by approx. 60 patients to the emergency room. Each patient gets an EKG done of their heart, and I have four measurements from each EKG. Then, each person gets their potassium level taken. That makes five variables: V2, V3, V4, QRSD, and K (short for potassium).
I would like to test the hypothesis that potassium level affects V2, V3, V4, and/or QSRD. That is, I'd like to run a test that, for instance, could detect that if potassium goes up, so does the QSRD etc.
I am not sure if ANOVA is correct here, or if regression is... Anyway, one of the big issues is that repeated-measures tests calls for a fixed number of measurements per participant... But in this case, each patient has a variable number of visits. Patient A might have 3 visits in the data set, and thus 3 sets of data. Meanwhile, patient B might have 7 visits and thus 7 sets of data.
Any guidance here?