Back to Basics on HAVS – Part 2: Causation

Since the late 1990s, the courts have approached the issues of diagnosis and causation of Hand-Arm Vibration Syndrome (“HAVS”), and quantification of general damages, by reference to HAVS’s two constituent components: vascular HAVS and sensorineural HAVS. There is also evidence, however, that hand-transmitted vibration can damage the musculoskeletal system.

Vascular HAVS involves damage to the blood vessels in the upper limbs (particularly the digital vascular tree) and the symptoms are similar to those experienced in the constitutional condition of Raynaud’s phenomenon (typically cold induced episodic whiteness of the fingers). Sensorineural HAVS involves damage to the peripheral nerves (peripheral neuropathy) in the upper limbs and can present with symptoms of numbness, reduced tactile discrimination and/or manipulative dexterity.

A claimant need only establish one of the two components, though both can be present. The staging (see below) is also made separately for each hand. The question of whether either HAVS component is established in a particular claimant, and the grading of its severity, is approached by reference to academic medical literature and clinical judgement, which has developed over time. 

The diagnosis of HAVS in civil claims principally involves clinical judgement exercised by appropriate medico-legal experts, and is usually based on (a) the history of symptoms provided by the patient, (b) the history of relevant and significant vibration exposure and (c) there being no evidence of an underlying cause to account for the symptoms (see Occupational Illness Litigation at 3-213). A useful resource for the challenges involved in the diagnosis of HAVS is the Industrial Injuries Advisory Council (IIAC)’s Position Paper 43 (2019), which noted in particular that:

• vascular attacks are episodic and may not be witnessed or provoked by cold testing, meaning the diagnosis relies on the patient’s history;
• vibration dose alone is not the only determining factor; and
• taking an accurate history of symptoms including their development can be a complex task.

In Armstrong v British Coal Corporation, unreported, 28 November 1996, CA, the Court of Appeal considered BCC’s appeal against a finding they were liable to seven out of nine plaintiffs, whose cases were selected as lead cases in HAVS group litigation (comprising some 25,000 similar claims), then known as Vibratory White Finger. On the question of the assessment of HAVS, Judge LJ said as follows:

The symptoms are now assessed by reference to classifications, the Taylor-Pelmear classification by stages, and since 1986, the Stockholm Workshop Scales which classify a vascular and a sensorineural component. These classifications are [blog author’s tabulation]:

Taylor-Pelmear

Stockholm Workshop Scale

… These classifications provide a valuable starting point in the assessment of damages, the valuation of each claim ultimately depending on the judge’s view of the true extent of the symptoms and their impact on the life of each individual plaintiff.  The fact that the classifications themselves refer to the “fingers”, or the “digits”, and indeed that the name of the condition itself is Vibratory White Finger, may divert attention from the fact that in a severe case this injury should properly be regarded as damaging the hand or hands rather than being confined to the fingers.

One of the outcomes of Armstrong was that the Department for Trade and Industry set up a tariff-based compensation scheme for miners with HAVS. As Lord Lloyd-Jones explained in the Supreme Court’s decision in the professional negligence claim in Edwards v Hugh James Ford Simey Solicitors [2019] 1 WLR 6549, the Stockholm Workshop Scale was used to grade HAVS in that scheme: see [1]-[3].

The Court of Appeal’s approval of Taylor-Palmear and the Stockholm Workshop Scale in Armstrong was also reflected in subsequent editions of the Judicial Studies Board (“JSB”) guidelines on the assessment of general damages in personal injury cases, which had become the Judicial College (“JC”) guidelines by the time of the publication of the 11^th edition in 2012. At the time of the decision in Armstrong, the 3^rd edition (1996) was current.

By the time of the publication of the 7^th edition of the JSB guidelines in 2004, reference to Taylor-Palmear had fallen away as that system had become obsolete, and it was stated in chapter 6(J) that “the Stockholm Workshop Scale is now the accepted table for grading the severity of the condition. The Scale classifies both the vascular and sensorineural components in two complementary tables. Individual assessment is made separately for each hand and for each finger“. That statement still appears in the current, 16^th edition (2022), at chapter 8(A), though the guidance continues to make clear that “the assessment of damages is therefore not strictly tied to the Stockholm Workshop Scale grading. It depends more on the extent of the symptoms and their impact, having regard [to the listed] factors“.

The Stockholm Workshop Scale has therefore stood as the pre-eminent grading tool for HAVS in the context of personal injury litigation for around 20 years. However, in 2019, CJM Poole et al. published their paper “International consensus criteria for diagnosing and staging hand-arm vibration syndrome.” International archives of occupational and environmental health, 92(1), 117-127. This drew on research since the publication of the Stockholm Workshop Scale in 1987, and aimed to “develop an up-to-date evidence-based classification for HAVS by seeking consensus between experts in the field“.

The paper is a useful source for anyone looking to critique the Stockholm Workshop Scale: criticisms include that some of the key terms such as ‘occasional’ and ‘frequent’ are too subjective, hence the authors’ view of the need for a more evidence-based and objective system of classification. One of the results of the paper was the production of Table 5, which is a potential rival to the Stockholm Workshop Scale, and their key conclusions have consequences for the diagnosis and grading of both components. The authors recommended that frequency of blanching should be dropped from the classification of HAVS and instead photographs of the fingers are taken during an attack of blanching for diagnostic confirmation of Raynaud’s phenomenon and for calculation of a blanching score (photographs of blanching, and indeed videos, was considered by the IIAC in PP43 but not made a mandatory requirement). Validated quantitative methods for establishing sensorineural HAVS were also recommended. This paper does not appear to have been cited in any judgment available on the major caselaw databases.

The major controversies in HAVS litigation on the issues of causation and quantum tend therefore to focus on matters of evidence and whether the two components can be proved. The paper of Poole et al. presages some of these issues, particularly that claimants in reality should look to provide good quality photographs of an attack of blanching to prove vascular HAVS, and cogent, objective evidence of sensorineural symptoms by reference to quantitative testing methods and a consistent history. 

In terms of consequential losses, such as special damages claims for the inability to carry out DIY and cleaning, the issues are also mainly evidential. The evidential issues involved were considered in another professional action that made its way to the Supreme Court, Perry v Raleys Solicitors [2020] AC 352. At trial, the judge rejected the claimant’s case he was unable to perform six domestic tasks because, for instance, photographs showed him engaging in fishing which he claimed to have given up due to a lack of manual dexterity: see Lord Briggs at [10].

To read Samuel Shelton’s blog on breach of duty in HAVS cases, please click here.

To read Jack McCracken’s further blog on causation in HAVS cases, please click here.