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.
Noun. 1. precursor-a substance from which another substance is formed (especially by a metabolic reaction). biochemistry-the organic chemistry of compounds and processes occurring in organisms; the effort to understand biology within the context of chemistry.recursor. n. 1. a person or thing that precedes and shows or announces someone or something to come; harbinger. 2. a predecessor or forerunner. 3. (Chemistry) a chemical substance that gives rise to another more important substance.