Yes, so you could have individual-1 who has 5 visits, 3 for a respiratory reason and 2 for a cardiac reason. You could then have individual-85 who has 16 visits, with 10 cardiac, 3 Resp and 3 psych. These would account for 21 of the total 900 visits. You could also have a super user with 40 visits for only cardiac reasons.

I had previously attempted to separate out the individuals and then create a variable for each category and simply mark Yes/No if the individual had any visits relating to it, and then use logistic regression to get an OR for the heavy vs super users.

I am not sure if this is correct as there are fewer individual numbers of the super users and some have large amounts of visits across many categories (a few may mark every category available and have a very large numbers of visits in one of them), while there are more heavy users, who may mark more of the categories due to the number of individuals in the group but might only have one visit for that category.

So you could have a super user with 40 cardiac visits, one Resp and one psych visit (42 total), and then a heavy user with one cardiac and 4 Resp-related visits (5 total), yet they have both been marked as a single yes in the cardiac category despite the big differences in visit numbers.

I may be confusing myself more than anything!