F‌‍‍‍‌‍‍‌‌‍‍‍‌‍‍‍‍‌‍‍or your IV OpDef: it sounds like you want to know how much

F‌‍‍‍‌‍‍‌‌‍‍‍‌‍‍‍‍‌‍‍or your IV OpDef: it sounds like you want to know how much they take (which would be the operational definition of your IV) . Drop your research question in the definition. You also mention “measure how long” und‌‍‍‍‌‍‍‌‌‍‍‍‌‍‍‍‍‌‍‍er your DV – are you interested in how much medication leads to “affects”? If so, then include how much and how long as your two IVs: IV1: how much medication they take IV2: how long they have been on the medicatio‌‍‍‍‌‍‍‌‌‍‍‍‌‍‍‍‍‌‍‍n