The Respondent successfully claimed that entitlement to Permanent Injury Benefit under an NHS benefit scheme was payable where employees, who sustained injury which was wholly or mainly attributable to their work, suffered a permanent loss of earnings as a result, even if that injury was not the sole or operative cause of their loss

Factual background

Mrs Karen Young, the Respondent (“R”), is a former community nurse who worked for the NHS. In February 2010, whilst at work, R sustained an injury causing pain in her neck and lower back whilst attending a patient. This in turn caused ongoing back pain which prevented her from working, and led to her employment being terminated on grounds of capability in July 2011. An MRI scan in July 2010 had demonstrated that she had a degenerative condition or disease of her spine which was much more severe than would be expected in a healthy woman of her age (she was 53 at the time).

She therefore applied to the Appellant (“A”) for Permanent Injury Benefit (“PIB”) under the provisions of the National Health Service (Injury Benefits) Regulations 1995 (“the Regulations”).

The Regulations provide that PIB is payable to any person working for a relevant body “whose earning ability is permanently reduced by more than 10 per cent, by reason of the injury” which is “sustained… in the course of [their] employment and which is wholly or mainly attributable to his employment”.

In giving its reasons for its rejection, it accepted that Regulation 3 was satisfied, namely that she had sustained an injury that was wholly or mainly attributable to her NHS employment. However, it was not accepted that Regulation 4 was satisfied, as it was held that that injury had not resulted in any Permanent Loss of Earning Ability (“PLOEA”). This was because the injury which she suffered at work would only have caused a temporary injury in a woman of her age who did not have a pre-existing condition. Thus, the condition which had permanently incapacitated her for work was her pre-existing condition which was not wholly or mainly attributable to her NHS employment. The PLOEA attached to that condition. A second appeal to the Deputy Pensions Ombudsman was not accepted.

R therefore appealed to the High Court. The argument centred on Regulation 4 and, specifically, the meaning of the phrase: “by reason of the injury”. The judge said that the meaning of this phrase incorporates a causation test, in relation to which the court was presented with a stark choice. The phrase either meant in this context that the injury sustained at work caused her PLOEA if it was an operative cause of it, or it meant that the injury sustained at work caused her PLOEA if it was the operative cause of it.

The judge determined that it was sufficient if the injury sustained at work was simply an operative cause. This, he states, was purely as a matter of language – “if A is said to cause B, it is sufficient for A to be a cause of B, it is not normally a necessary requirement before A can be said to have caused B, that A is the sole or dominant cause”.

He appreciated the anomaly identified that an injury which was wholly or mainly due to employment, but which was only a contributory cause of the PLOEA should trigger the entire benefit, but stated that this was not a sufficient basis on which to displace the normal use of language.

The judge further referred to the “eggshell skull” concept in tort law and rejected the submission that it had no place in this context.

Finally, he concluded that A had asked the wrong question. The question they should have asked was not what impact the injury would have had on a woman of R’s age who had no pre-existing condition, but rather what impact it had on R given her pre-existing condition. This would not mean necessarily that the injury will have been an operative cause of the PLOEA, for it may be the injury was something that even for R actually had no permanent effect, and that the permanent effect was entirely attributable to her pre-existing condition.

The judge therefore allowed the appeal, finding that the determination of the Deputy Pensions Ombudsman be set aside and the matter be remitted to A to answer the right question. A appealed that finding.

The issues

The Court of Appeal had to determine the following issues, which were submitted by the parties.

A submitted the following:

  • R’s underlying disease was not attributable to her employment, and that on the correct construction of Regulation 4, R should not be entitled to PIB because her underlying condition was the operative cause of her PLOEA.
  • The trial judge had inappropriately applied a material contribution test to the Regulations and had imported the eggshell skull concept into this area.
  • PIB was a generous scheme under which it should only be payable if the PLOEA was wholly or mainly attributable to the injury at work. The effect of the trial judge’s construction was therefore that if an employee suffers any injury at work and their underlying condition is triggered, PIB is payable even though the underlying condition was the operative cause of their PLOEA.

R submitted as follows:

  • The trial judge was correct to construe “by reason of” as meaning that the injury at work must be “an operative cause”. The argument that the injury at work had to be the operative cause involved an impermissible writing into Regulation 4 of the words “wholly or mainly” before “by reason of”. The fact that the words “wholly or mainly” were added by amendment to Regulation 3 but not to Regulation 4 was fatal to A’s argument that this phrase could be inferred here.
  • The trial judge was simply deciding that A had asked the wrong question.
  • The judge was not relying on the eggshell skull principle to aid its construction of Regulation 4.


Flaux LJ gave the main judgment. He stated that once it is accepted, as it is here, that the injury was wholly or mainly attributable to R’s employment, so as to satisfy Regulation 3, the judge’s construction of Regulation 4 must be correct. The words “by reason of” import a but-for causation test, not a construction that the injury is the operative cause. That construction involves reading across the words “wholly or mainly” from Regulation 3, which is wholly impermissible.

He went on to state that the words “by reason of” can mean both that the relevant matter is the causa sin qua non (the “but for” test) of what occurred and the causa causans (the final and immediate cause) of what has occurred. However here, an argument that Regulation 4 requires that the injury be the causa causans of the PLOEA was not presented. Rather, he was presented with the rival constructions of Regulation, namely whether the PLOEA was wholly or mainly by reason of the injury or that the injury was an effective or operative cause of the PLOEA. The latter is clearly the correct construction.

Flaux J held that R was correct that the trial judge was simply stating that the correct question has not yet been asked. He said that when it is, it could emerge on the medical evidence even without the injury at work the underlying condition would always have rendered her unable to work.

Finally, R was correct, according to Flaux LJ, that the judge had not applied a material contribution test nor used the eggshell skull principle in his reasoning.

The appeal was accordingly dismissed.


Although of narrow immediate application, this judgment will give hope to NHS employees who have been injured in their employment and are wishing to claim PIB through this statutory scheme.

However, more widely, this judgment demonstrates that when analysing statutory provisions, the court will look primarily to the normal meaning of the language used in each individual provision. Attempts to deploy phraseology that exist in one part of the statute into other discrete parts of the statute where it does not exist will be difficult to do successfully.

It further shows that, when evaluating statutory phrases such as “by reason of” which are not attached to further caveats, a more expansive definition will more likely be preferred to a narrower one. In part, it seems that is because a more expansive definition makes greater sense from a purely semantic perspective.