Clinical judgment and sometimes ethical judgment enter into these decisions where there are often no right or wrong answers and where there are no textbooks or RCTs that tell us what to do.
predecessor - something that precedes and indicates the approach of something or someone. harbinger, herald, forerunner, precursor. indicant, indication - something that serves to indicate or suggest; an indication of foul play; indications of strain; symptoms are the prime indicants of disease.
belonging or pertaining to the origin or beginning of something, or to a thing at its beginning: The book still has its original binding. 2. new; fresh; inventive; novel: an original way of advertising. 3. arising or proceeding independently of anything else: an original view of history.