I have a dataset with multiple observations per person. Each observation pertains to instances where a person visits the doctor. I created an outcome variable based on the amount of time that has elapsed before the next doctor visit: 1 if the next visit is within 6 months and 0 otherwise. There are also a number of demographic variables (gender, race, etc) on the dataset.
Is there any scenario where a statistical test like ttest or chisquare can be performed with these data without flattening to person level? Could I for example test for a relationship between the outcome and say, gender, even though possible that a person could have a different outcome depending on the date of their next doctor visit?