As an example, I have two class (say A and B). I would like to determine if age, gender, location etc. is associated with class B. My initial thought is to perform a multivariable analysis using logistic regression. The problem is that samples could belong to both class. For example, a patient (sample) could belong in class A between January and March then class B in December. Hence, this particular child is in both class in the dataset. If this problem exist, can I still perform a multivariate analysis using logistic regression? Are there any limitations? Please feel free to suggest other methods I can use to answer the question.
EDIT: AN EXAMPLE OF HOW A SAMPLE CAN BE IN BOTH CLASS
During a year or data period, patient A (sample) could have been placed in multiple short-term placements. As an example, let's assume patient had two placement in a year. If patient A stayed in the first placement for less than 20 days, that's okay. But if patient A stayed in the second placement for more than 20 days then it's problem. I want to determine if any patient related factors are responsible for patient A staying more than 20 days? So I created a class l label for duration of stay: <20 days & >= 20 days. Hence patient A would be in both class - First placement was less than 20 days and second placement was greater than 20 days.