What probability of success determines whether a treatment is worth undertaking

What probability of success determines whether a treatment is worth undertaking (a question of odds), and what quality of outcome is worth undertaking a treatment (a question of ends)? Does the justice principle affect how much decision-making power and authority health care professionals should have in debating the odds-and-ends of treatment decisions? Does the principle of personal autonomy require the odds-and-ends of treatment decisions be shared with the patient receiving the care? Alternatively, should patients have absolute authority to decide what treatment odds-and-ends they will accept?

This is for a discussion post! Please provide 250 words in your response!