I agree with all of the responses here. You cannot just consistently connect a level of service with a complaint/diagnosis or with a management option (Rx, OTC) without taking the documentation/whole visit into account. I have audited thousands of records where cough and/or nausea are the chief complaint and they can vary widely as far as level once they are audited. Could you possibly assume many simple complaints of a cough are self-limited or minor? Maybe. However, what if the patient is a child, comes in with mom who gives the history, also has asthma, they do 3 labs, chest XR, and give prescription cough meds? That would push it to moderate if coding by MDM.
Contrast that with an adult, complains of a dry cough only for a day or two, no labs, nothing else wrong, no other health problems, they tell them to hydrate, use throat lozenges, and try OTC cough syrup at night (they just moved from a humid to a dry climate area)? That's probably a 2 if coding by MDM.
We have to look at the whole picture.