Thanks - yes I can but then we are aggregating the figures for each individual and performing logistic regression according to individual characteristics so it needs to be individual level counts.
I am really new to R so making a new column is really difficult! Is it something like
mutate(approved_name_combination = approved_name IF *it happens to be called co-codamol), just don't know how to do the IF thing? Presumably then for drugs not called co-codamol then the new variable would have a value of 0?
Many thanks again, really appreciate your help.
Clare