What is the test for mitigation in medical malpractice cases?

The difficulty in this case lies in the fact the plaintiff sincerely held strong negative views about taking medications in general and methotrexate in particular. His negative views about the potential ill-effects of methotrexate were fuelled in part by his own misleading internet research. In the circumstances of this case, there is no question that based on a pure objective test, the plaintiff ought to have followed his doctors’ advice. Likewise, if that were all that needed to be considered, the correct result again is obvious because in Canada the law does not excuse objectively unreasonable choices, so long as the plaintiff has the requisite capacity to make them. Janiak v. Ippolito, 1985 CanLII 62 (SCC), [1985] 1 S.C.R. 146, is the foundational case for the law of mitigation in Canada. Wilson J., speaking for the court explains: 24 Non-pathological but distinctive subjective attributes of the plaintiff's personality and mental composition are ignored in favour of an objective assessment of the reasonableness of his choice. So long as he is capable of choice the assumption of tort damages theory must be that he himself assumes the cost of any unreasonable decision.