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Sufficient Evidence of Commonality in Multi-product Medical Devices Class Actions - Cautionary Tales

5 minute read

In order to prove that a group of related medical devices have sufficient commonality to proceed as one class action, the plaintiff must present evidence that demonstrates ‘some basis in fact' not only that there is commonality between the devices but also that there is commonality in the allegations, e.g. design defect or inadequate warning. Only where the plaintiff has not satisfied this burden will any evidence going to these issues presented by the defendant be considered and weighed.

This conclusion was recently articulated following a series of certification reasons in multi-product medical device class actions. Each of the three cases alleged commonality of the devices and commonality of the allegations regarding different yet related medical devices as their core concern on certification. Two actions were with respect to products containing transvaginal mesh and the other concerned hip implant devices.1

  • In O'Brien v Bard, 2015 ONSC 2470, the motion for certification was dismissed subject to the plaintiffs requesting a case conference to bring an ‘alternatives motion'. Nineteen different products were in issue. The fact that each product contained surgical mesh was insufficient to demonstrate commonality. The plaintiff also did not present evidence that the proposed common element of mesh was, on its own, dangerous, or that there was commonality in product design decisions. The defence evidence was used by the case management judge to conclude that 19 separate design decisions were made - thereby negating commonality.2
  • In Vester v. Boston Scientific, 2015 ONSC 7950, there were nine products in issue. This time it was established that the same mesh was used in all devices. The defence evidence suggested that the use of the mesh was standard and the plaintiff did not provide evidence that the mesh was dangerous. The plaintiff also did not establish that there was commonality in an alleged design defect or inadequate warning. It was therefore possible that there was no design defect or up to nine design defects. Further specificity was required and the motion was adjourned.3
  • In Dine v Biomet, 2015 ONSC 7050, there were three devices in issue. These were all large-head metal-on-metal hip implants. Two of the three were total hip replacement systems and the third was a resurfacing technology. The plaintiff presented evidence that these devices had high revision rates, were associated with risky metal-related pathology and that the three devices were treated as one product group - including by the defendant. The defendant submitted expert opinions that refuted the revision rates and evidence of the plaintiff's experts. This action was certified.4 The defendants sought leave to appeal in part on the ground that there were conflicting decisions, referencing in particular O'Brien and Vester.5

In denying leave to appeal Justice Then reviewed the above three decisions and concluded that they were not conflicting. Justice Then found that even though there were different outcomes based on what was arguably similar evidence presented by the defendants, there were varying findings of the sufficiency of the plaintiffs' evidence that was before each Court.

In Dine the case management judge found that the plaintiffs had discharged their evidentiary burden of demonstrating some basis in fact of commonality. As a result, while the defendants disputed this, it was not appropriate to consider the defendants' evidence as certification is not the proper forum for adjudication on the merits.6 In contrast in both O'Brien and Vester, the case management judge found that the plaintiffs had not met their evidentiary burden of proving commonality.7

As per Justice Then, the above decisions are consistent amongst themselves and also consistent with the principles established by the Supreme Court in Hollick8 and, more recently, in Pro-Sys, Sun-Rype and AIC.9 In the context of commonality what is generally required is evidence that the common issue actually exists and that the issue can be answered in common.10  There is to be no weighing of the plaintiff's evidence against directly contradictory evidence from the defendant. However, weighing the plaintiff's evidence in its own right or weighing the plaintiff's evidence and considering and relying on the defendant's evidence to fill in gaps in the record to find that the plaintiffs have not met their evidentiary burden is permissible.11

Unlike O'Brien and Vester, in Dine, the case management judge found that the plaintiff had established a sufficient basis in fact for commonality. As a result, the defendant's evidence was aimed at contradicting the plaintiff's evidence and was not properly considered on certification.

In multi-product medical device class actions both plaintiffs and defendants would be wise to direct their energies towards analysing the sufficiency of the evidence on the common issues.

The content contained in these blogs is intended to provide information about the subject matter and is not intended as legal advice. If you would like further information or advice on any of the subjects discussed in a blog post, please contact the author.


1An earlier discussion of these cases, which we drew from for this posting, can be found in our paper “2015 Update: Class Actions in Health Law – Medical Products Liability and Actions Against Health Professionals”, The OBA Institute Health Law Program, February 4, 2016

2O'Brien v Bard, 2015 ONSC 2470 at paras 3, 125, 136, and 255-256; Dine v Biomet, 2016 ONSC 4039 at para 38

3Vester v Boston Scientific, 2015 ONSC 7950 at paras 55-57, 119-123, 126, 135 and 138; Dine v Biomet, 2016 ONSC 4039 at para 38

4Dine v Biomet, 2015 ONSC 7050 at paras 4, 21-31, 34, 37-40 and 65; Dine v Biomet, 2016 ONSC 4039 at para 39

5Dine v Biomet, 2016 ONSC 4039 at para 9

6Dine v Biomet, 2016 ONSC 4039 at paras 25 and 30

7Dine v Biomet, 2016 ONSC 4039 at paras 26-29

8Hollick v Toronto (City), 2001 SCC 68

9Pro-Sys Consultants Ltd. v Microsoft Corp., 2013 SCC 57; Sun-Rype Products Ltd. v Archer Daniels Midland Co, 2013 SCC 58; AIC Ltd. v Fischer 2013 SCC 69

10Dine v Biomet, 2016 ONSC 4039 at paras 31-33

11Dine v Biomet, 2016 ONSC 4039 at paras 35-36


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