Predicting risk of death based on personalised and objective clinical indicators is an improvement over intuition and clinical judgement. Risk assessment can benefit clinicians by improving prognostic certainty, and truth disclosure helps patients and families by preventing futile management. Some argue that consent should be obtained before a patient is given an estimate of their prognosis as disclosure of bad news can overburden patients. In this article, we argue that it is unethical not to use existing person-specific information to guide diagnosis and shared decision making on management in partnership with well-informed patients. Disclosure of a poor prognosis should be normalised in personalised medicine, performed incrementally and with sensitivity so that it is acceptable to patients, and only occur if patients want to know it. However, a requirement of consent for truth disclosure should not be mandatory. Despite some level of imprecision, personalised risk estimations can be used to tailor management to the patient's informed wishes and ensure that healthcare providers and families are acting ethically in the patient's best interest.