What do we call a doctor's prediction

Solution 1:

The word is "prognosis". (Merriam-Webster dictionary)

1: a doctor's opinion about how someone will recover from an illness or injury

2: a judgment about what is going to happen in the future

• "It's a very good prognosis. She will recover completely"
• "He's undergone surgery plus chemotherapy. Still it's a somber prognosis."
• "What is my prognosis, doctor? Very good, Mrs Barnard. The tumor has been removed and you are cured."

Solution 2:

Medicine: prognosis (a prediction of) the likely outcome of a disease in a general or particular case... the alternative word is "prognostication"