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A "Holistic" Approach to Defect under the Consumer Protection Act 1987

On 6 December 2016, in Wilkes v DePuy International Limited, the High Court gave judgment on the question of ‘defect’ in relation to metal-on-metal hip prostheses, managed under a group litigation order. The judgment adopts a “holistic” approach to defect, potentially helpful to producers and their insurers in the pharmaceutical and medical device sectors, and beyond.

The claim concerned the stem of a hip replacement implant which had fractured three years after implantation. It was manufactured as the producer had intended, but the claimant argued that the design made the stem susceptible to failure, that the producer should have eliminated this risk by adopting a different design, and that the product was defective under the Consumer Protection Act 1987 (CPA). However, the claimant failed to establish defect.

The Court noted from the text of Annex I of the Medical Devices Directive (93/42/EC) that “acceptable risks” were to be balanced against “the benefits to the patient”, and noted from chapter 5 of the textbook “Clinical Negligence” (5th edition, Powers QC and Barton) that licenses for pharmaceutical products were only to be granted where there is “deemed to be a positive balance of risks and benefits”, or the product is, in the regulator’s words, “acceptably safe”.

The fact that a ‘risk-benefit’ analysis is conducted before a pharmaceutical product or medical device is allowed onto the market clearly underpinned the Court’s approach in this case.

A departure from old case law

Since 2001 the weighty judgment of Burton J in A v National Blood Authority (“A v NBA”) has been applied in many product liability claims. However, this judgment very substantially departs from that case.

In A v NBA, Burton J stated that the Court should first identify “the harmful characteristic which caused the injury”. Then it should determine whether the product was ‘standard’ or ‘non-standard’ i.e. did it perform in the manner the producer intended. Finally, defect should be considered against those facts.

This approach was criticised. In particular, the DePuy judgment stated that “concentration at this early stage on causation is a distraction from the true focus…which is on defect”.

It also stated that categorising products as ‘standard’ or ‘non-standard’ was “unnecessary and undesirable” and “positively unhelpful and potentially dangerous”. Following Burton J’s approach would mean that a risk-benefit analysis could not be considered for ‘non-standard’ products. However, the Court called for a more flexible approach.

A v NBA also held that we should consider the ‘legitimate expectation’ of persons generally, when considering defect and the level of safety that persons generally are entitled to expect. That term was invented by that case. However, the DePuy judgment stated that “what persons generally are “entitled to expect” requires no gloss” and that considering ‘legitimate expectation’ might be unnecessary and unhelpful.

Key principles to take forward

The following points will be relevant to a number of product liability claims, going forward.

  1.  A risk-benefit analysis and the avoidability of risk of harm can be considered, when determining defect. Some caution was exercised by the Court here. The CPA emphasises a focus on the product itself, and not on the acts or omissions of the producer. Yet a risk-benefit analysis involves consideration of, for example, the cost and practicability of the producer adopting a different design. In striking a balance, the Court held that although a “detailed consideration” of whether a risk is avoidable “is unlikely to be fruitful”, “the ease and extent to which a risk can be eliminated or mitigated may be a circumstance that bears upon the issue of the level of safety that the public generally is entitled to expect”.

  2. Compliance (or non-compliance) with standards and product-specific regulations “will have considerable weight”. Where “every aspect of the product’s design, manufacture and marketing has been the subject of the substantial scrutiny, by a regulatory body comprised of individuals selected for their experience and expertise in the product including its safety”, and the product has been assessed by that body to be acceptable, it is “powerful evidence” in favour of the producer, and “it may be challenging” for a claimant to prove defect.

  3. Where there is a “learned intermediary” e.g. a surgeon, in the chain between producer and claimant, this is a relevant circumstance to take into account when considering defect. For example, the fact that the intermediary applied his/her knowledge to choose the particular product for a particular patient, that they read and conveyed to the patient the risks and warnings given by the producer, and that the patient gave informed consent, can be considered.

  4. Although there may be an inherent risk arising from a particular design, and it may be possible to eliminate that risk by adopting a different design, it does not necessarily make a product defective, because eliminating the risk in that way might “result in disbenefits that would outweigh the benefits”. Put another way, “the fact that a safer design can be envisaged does not mean that a current product is defective”.

In relation to causation, the following points are important.

  1.  The claimant must prove a causal link between the defect and damage, but the claimant is not obliged to “prove the cause of that lack of safety or why the product failed” (upholding Ide v ATB Sales Limited). 

  2. Where a claimant’s case is based on a defect causing an increased risk, the question arises as to whether the claimant must prove a doubling of the risk to establish causation (which is the traditional approach), or has a lesser burden of proving a material contribution to risk (the ‘Fairchild’ approach). The Court recognised that this would require “careful consideration”. However, it did not need to answer the question in this case and therefore left it open.

From a producer’s perspective, this judgment is helpful in that it recognises that risks can be acceptable even in products as safety-critical as medicines and medical devices, where those risks are outweighed by the benefits, and despite the fact that the risk could have been eliminated. Preserving evidence to demonstrate compliance with regulations and standards may greatly assist in demonstrating that the product was not defective. Allowing consideration of risk-benefit even in ‘non-standard’ cases, and not allowing causation to drive the determination of defect significantly opens up the scope for producers to defend products that they may otherwise have had to accept as defective.


DWF represents parties in relation to the ‘metal-on-metal’ hip prostheses claims. David Kidman represented the lead defendant in the PIP Breast Implant Group Litigation and handles a range of product liability claims for insurers and producers. 

For more information, please contact David Kidman, Partner on +44 (0)20 7645 4314 or at david.kidman@dwf.law.

By David Kidman

This information is intended as a general discussion surrounding the topics covered and is for guidance purposes only. It does not constitute legal advice and should not be regarded as a substitute for taking legal advice. DWF is not responsible for any activity undertaken based on this information.