We are planning a study in which patients report their pain and opioid use following surgery. Ideally patients would report daily until they no longer need opioids. Surely some will skip days and others will simply stop reporting before they complete the program. I am looking for suggestions on what to do with missing data. For example, is there a form of imputation that would apply for interpolating the missing in-between reports data? And maybe there is some other method for how to handle the patients who quit the program early.