In Charlton v. Abbott Laboratories, Ltd., 2015 BCCA 26 (Charlton), the British Columbia Court of Appeal clarified the evidentiary threshold plaintiffs must satisfy at the certification stage in the context of product liability class actions. In particular, the Court confirmed that plaintiffs alleging that a product causes adverse effects or injury must adduce evidence of a workable methodology to demonstrate that the product in question was capable of causing adverse effects on a class-wide basis. In so ruling, the Court reiterated the principles articulated by the Supreme Court in the 2013 “indirect purchaser trilogy,”  and affirmed their application to the product liability context. Ultimately, the plaintiffs in Charlton failed to adduce sufficient evidence of general causation, which proved fatal to the certification of the action.


In 2011, a class action was commenced against Abbott Laboratories, Ltd. (Abbott) and Apotex, Inc. (Apotex) on behalf of all individuals in Canada who were prescribed a drug containing sibutramine, on the basis that ingestion of sibutramine allegedly caused or contributed to adverse cardiovascular health, including heart attacks, strokes, increased blood pressure, increased heart rate and irregular heartbeat. The plaintiffs pleaded various causes of action, including negligence, failure to warn and breaches of the B.C. Business Practices and Consumer Protection Act and the Competition Act, in addition to seeking damages pursuant to the doctrine of waiver of tort.

Notably, some of the members of the class reported suffering from cardiovascular events like heart attacks or strokes after being prescribed sibutramine, while others had not. Furthermore, it was unclear from the evidence how many class members (if any) had a pre-existing history of cardiovascular illness.

Expert Evidence at Certification

The plaintiffs filed two medical expert reports in support of their application for certification, and the defendants filed two responding expert reports. After considering the expert evidence as whole, the Court of Appeal summarized the evidence as follows:

  • There was some evidence of increased risk for cardiovascular events in individuals with pre-existing heart problems.
  • The Canadian product monograph cautioned against prescribing sibutramine to patients with a history of cardiovascular disease.
  • There was no evidence presented to suggest that the drugs in question had in fact been prescribed to individuals with pre-existing conditions.
  • The extent of the risk for individuals with no history of cardiovascular disease had not been studied, and the statistical evidence that was available did not demonstrate a measurable increase in the risk for patients with no history of cardiovascular disease.

The B.C. Supreme Court’s Decision on Certification

The certification judge found the claim met the test for certification in all respects and certified the class, which was defined as “[a]ll persons in Canada who were prescribed and ingested [sibutramine] … .”

Among the various common issues certified by the certification judge was the issue of whether sibutramine causes or contributes to heart attacks, strokes and irregular heartbeat in relation to all Canadian patients who were prescribed and ingested drugs containing sibutramine, whether or not they had a pre-existing cardiovascular condition.

The appellants appealed the certification decision, arguing that the certification judge erred in principle by certifying the proceedings. The appellants focused their argument on the asserted failure of the plaintiffs to lead evidence of a methodology for establishing general causation on a class-wide basis.

B.C. Court of Appeal Overturns Certification

Relying on the Supreme Court of Canada’s 2013 trilogy of cases in the indirect purchaser context,1 the B.C. Court of Appeal reiterated the principle that a class action should not be certified where a plaintiff fails to adduce some evidentiary basis for a methodology that could be used by the Court to answer the common questions. In this regard, the Court observed that the question of class-wide general causation should not be certified as a common issue without evidence of a methodology to prove such causation in respect of the class as a whole. In so commenting, the Court drew a distinction between certain prior pharmaceutical class actions in which causation had been held to be sufficiently established on the basis of evidence of a general increase in risk to the class caused by using the drug in question and the case before it, where no such generalized risk data was available.

The Court ultimately concluded that the lack of a methodology for demonstrating general causation was an insurmountable evidentiary hurdle:

         [t]here was no evidence of a methodology for establishing that the class as a whole, as opposed to those who were wrongly prescribed sibutramine despite a history of disease, was affected or put at risk by its use of sibutramine. …

While there is no dispute that those with pre-existing cardiopulmonary disease are at a statistically increased risk of adverse cardiac events, this is not a case where the experts disagree on the extent of the risk, but rather, a case where the experts are uncertain whether there is a risk to the class as a whole and cannot describe a methodology for addressing that question.

The remaining common issues hinged upon a finding of general causation on a class-wide basis. Accordingly, absent a workable methodology for addressing causation, the Court concluded that certification should not have been granted and set aside the certification order of the trial judge.

Notably, in denying certification, the B.C. Court of Appeal also harmonized an apparent inconsistency between the trial judge’s decision in Charlton and a parallel proceeding in Québec in which certification had been denied (though admittedly in the context of a different legal regime). In particular, the Québec Superior Court was presented with a similar evidentiary record to that in Charlton, and held in a decision released in 2012 that the evidence put forward by the plaintiffs in that case was insufficient to meet the test for class action authorization pursuant to section 1003 of the Québec Code of Civil Procedure.

Implications: A Stricter Approach to Certification?

The appellate decision in Charlton represents a clear affirmation of the recent judicial statements to the effect that class action plaintiffs bear the burden of establishing causation on a class-wide basis. In particular, the case illustrates the fact that causation cannot simply be presumed, nor is it sufficient for plaintiffs to simply argue that a product could – in the abstract – cause injury to certain consumers. Rather, the plaintiffs must adduce some evidence – or at least a workable methodology at the certification stage – in order to satisfy the courts that some manner of class-wide conclusions regarding causation could reasonably be drawn.

Moreover, the case is also reflective of the increased willingness on the part of the courts to intervene at the certification stage where the underlying merits of the proceedings are somehow problematic. In particular, as discussed in a previous Osler Update, the courts appear to have moved away from a rigid application of the certification criteria to a broader consideration of the proceedings as a whole. Although the certification test is not intended to be a test of the merits of the action, the decision in Charlton nonetheless demonstrates the crucial importance of the evidentiary record, even at the certification stage. In the wake of the Supreme Court of Canada’s reaffirmation that certification should serve as a “meaningful screening device"2, courts are now carefully considering the inter-relationship between the definition of the class, the common issues and the available evidence to determine not only whether the certification test has been met, but also whether the matter should be allowed to proceed more generally.