What is the test for aggregate damages in a medical malpractice case?

On an aggregate damages claim for compensatory damages, the issue is whether the court can find, on the evidence at the common issues trial, that there is a commonality of harm in that all class members will suffer to some degree with a base level of suffering experienced by all class members: Reddock v. Canada (Attorney General), 2019 ONSC 5053, at paras. 179 and 269.

Such an approach has been adopted to order base-line aggregate damages in claims involving systemic negligence and Charter breaches for solitary confinement: Brazeau, Reddock, and Francis v. Ontario, 2020 ONSC 1644, at para. 296. b. Individual damages questions are not relevant to an aggregate damages claim