Modified Objective Test

The modified objective test is the causation framework that Ontario courts apply in informed consent cases. It was established by the Supreme Court of Canada in Reibl v Hughes, [1980] 2 SCR 880, where the Court rejected both a purely subjective test (what would this particular plaintiff have done?) and a purely objective test (what would the reasonable person have done?) in favour of a hybrid: what would a reasonable person in the plaintiff’s particular circumstances have done, had the risks of the proposed treatment been properly disclosed?

The “modification” of the objective test is the part that attends to the plaintiff’s circumstances. A reasonable thirty-five-year-old construction worker with three children to support may make a different decision than a reasonable seventy-five-year-old retiree with significant comorbidities, and the test invites the court to consider those individual circumstances rather than collapsing every plaintiff into a notional reasonable person.

In practice, the modified objective test is more favourable to defendants than a purely subjective test would be, because the plaintiff’s post-hoc evidence that they personally would have refused the treatment carries less weight against the objective question of what a reasonable patient would have done. The test has been refined in subsequent cases, including the Supreme Court of Canada’s decision in Arndt v Smith, [1997] 2 SCR 539, which addressed how to incorporate the plaintiff’s particular fears or concerns into the analysis.

Posts tagged Modified Objective Test analyze Ontario decisions on causation in informed consent claims.