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.
Precursor is defined as something that led to the creation of something similar but new. An example of precursor is how radio came before but helped create television. The definition of a precursor is something or someone that came before. An example of a precursor is the dark clouds before a storm. a person or thing that goes before; forerunner; harbinger.