P underwent an operation that carried a 1% chance of paralysing the patient. D didn’t warn P of this and P was paralysed. She sued D for negligence. HL said that the Bolam test was to be applied in deciding whether the doctor was negligent in not disclosing the risks. In this case there was a reasonable body of professional opinion that would not have told D of the risk. However there were cases where the risk of grave injury was “substantial” and in that case, even if there was a reasonable body of opinion that would not disclose, the judge could find that such non-disclosure was negligent (unless there was a special reason e.g. emergency).
Lord Diplock: it is not the courts’ job to say which body of opinion it thinks preferable since the courts do not have the expertise of the professionals. If a patient asks about the risks directly, a doctor has to tell them honestly. However if the information is unsought, a doctor should not be forced to give info which may deter a patient from undergoing an operation that is in their own interest.
Lord Bridge: So as to prevent the medical profession from inhibiting the knowledge of patients, he says that where there is a substantial risk of grave injury, the court may decide that non-disclosure was unreasonable, even if medical professionals think it reasonable.