International consensus criteria for diagnosing and staging hand-arm vibration syndrome.

PURPOSE: In the 30 years since the Stockholm Workshop Scale (SWS) was published, the scientific literature on hand-arm vibration syndrome (HAVS) has grown and experience has been gained in its practical application. This research was undertaken to develop an up-to-date evidence-based classification for HAVS by seeking consensus between experts in the field. METHODS: Seven occupational physicians who are clinically active and have had work published on HAVS in the last 10 years were asked to independently take part in a three-round iterative Delphi process. Consensus was taken when 5/7 (72%) agreed with a particular statement. Experts were asked to provide evidence from the literature or data from their own research to support their views. RESULTS: Consensus was achieved for most of the questions that were used to develop an updated staging system for HAVS. The vascular and neurological components from the SWS are retained, but ambiguous descriptors and tests without adequately developed methodology such as tactile discrimination, or discriminating power such as grip strength, are not included in the new staging system. A blanching score taken from photographs of the hands during vasospastic episodes is recommended in place of self-recall and frequency of attacks to stage vascular HAVS. Methods with the best evidence base are described for assessing sensory perception and dexterity. CONCLUSIONS: A new classification has been developed with three stages for the clinical classification of vascular and neurological HAVS based on international consensus. We recommend it replaces the SWS for clinical and research purposes.

An assessment of the effects of exposure to vibration, smoking, alcohol and diabetes on the prevalence of Dupuytren's disease in 97,537 miners.

A consecutive sample of 97,537 miners seeking compensation for Hand-Arm Vibration Syndrome were examined in a medical assessment process which included documentation of age, hand dominance, Dupuytren's disease, years of vibration exposure, history of diabetes, smoking habits and units of alcohol consumption per week. The prime determinant of prevalence of Dupuytren's disease was age, and all other factors investigated were corrected for age. There was no statistically significant correlation between years of exposure to vibration and the prevalence of Dupuytren's disease. There was a statistically significant association with smoking, alcohol consumption and diabetes mellitus, with the heaviest smokers having an odds ratio (OR) of 1.31 (95% CI, 1.17, 1.47), the heaviest drinkers (in excess of 22 units a week) having an OR of 1.59 (95% CI, 1.47, 1.72) and diabetes mellitus patients having an increase in the odds of having Dupuytren's disease of 1.52 (95% CI 1.30, 1.77).

Carpal tunnel syndrome in association with hand-arm vibration syndrome: a review of claimants seeking compensation in the Mining Industry.

Twenty six thousand eight hundred and forty-two miners seeking compensation were clinically assessed for vascular and neurosensory impairment arising from exposure to occupational hand-arm vibration (Hand-Arm Vibration Syndrome). They were also assessed clinically for Carpal Tunnel Syndrome which, if present, would result in additional compensation. Fifteen per cent were assessed as having both HAVS and CTS. Thirty-eight per cent of claimants had nocturnal wakening, 1.3% wasting of abductor pollicis brevis, 15% had a positive Tinel's test and 20% had a positive Phalen's test. The 15% prevalence reported is lower than the rates cited previously in several small population studies of workers exposed to vibration. This paper reports the results of the assessment process and discusses the difficulty of discriminating Carpal Tunnel Syndrome from diffuse neurosensory impairment arising from HAVS.

Use of sensorineural tests in a large volume of medico-legal compensation claims for HAVS.

BACKGROUND: The Department of Trade and Industry set up a contract to examine miners and ex-miners claiming compensation for hand-arm vibration syndrome (HAVS). They had been exposed to hand-transmitted vibration. Over 100,000 have now been examined using sensorineural tests as part of that process. AIMS: The purpose of this paper was to examine the internal consistency of the vibrotactile threshold test (VTT) and the thermal aesthesiometry test (TA). METHODS: In 18 centres across the UK, nurses were trained to perform the measurement of VTT and TA in a controlled standardized manner. These tests were to aid the staging of the neurological component of the Stockholm Workshop Scales. The staging of this component was modified by dividing stage 2SN into 2SN (early) and 2SN (late). The test results and an automatic neurological staging were presented to the examining doctor following the clinical examination. The results of these sensorineural tests were held on a central database. The results and analysis of the first 57,000 tests are reported. RESULTS: The correlations within the VTT and TA scores were consistent with reliable measures. However, these correlations were not of such strength as to allow reliance on the results of a single test when making an assessment of the severity of neurological damage. CONCLUSIONS: Different end organs and nerve fibres should be tested when making an assessment of damage in the sensorineural component of HAVS. The correlations demonstrated for the VTT and TA suggest that they are of value in assessing these claimants and would be for other vibration exposed workers.

A medical assessment process for a large volume of medico-legal compensation claims for hand-arm vibration syndrome.

BACKGROUND: The judgement on preliminary issues of nine lead cases of suspected hand-arm vibration syndrome (HAVS) in former coal miners in the UK ruled that there was evidence of damage and breach of duty of care (Armstrong and Others v. British Coal, 1996). In anticipation of > 120 000 cases and at significant cost, a handling agreement was prepared in 1999. This recommended a single medical assessment process (MAP) to determine general damages for which almost 200 doctors attended 2 days of training. AIMS: This paper outlines the assessment process and the results to date. METHODS: Seventeen test centres across the UK were commissioned. Standardization of the performance by both the doctors and technicians within individual examination centres and across all centres was necessary. A pragmatic solution using 'best available assessment techniques', whilst at the same time coping with the large number of claimants, was required. Doctors were trained to administer questionnaires for clinical symptoms, past medical history and occupational history, and a standardized clinical assessment pro-forma. Three standardized tests were used: vibrotactile thresholds, thermal aesthesiometry and cold water provocation testing. A modification of the Stockholm Workshop Scales and scoring system was adopted. At time of writing, 52 490 claimants had been assessed by the MAP. RESULTS: Analysis of results showed that 5% were assessed at 0SN, 15% at 1SN, 18% at 2SN (early), 28% at 2SN (late), 33% at 3SN, 21% at 0V, 13% at 1V, 38% at 2V and 28% at 3V. CONCLUSION: It is concluded that the MAP is a practical and time-efficient tool for assessing a large volume of claimants with suspected HAVS. Further analysis of the process and staging is required to confirm its validity as a medico-legal examination.

Cold provocation testing and hand-arm vibration syndrome--an audit of the results of the Department of Trade and Industry scheme for the evaluation of miners.

BACKGROUND: Hand-arm vibration syndrome (HAVS) is a major industrial disease that causes considerable morbidity among workers exposed to vibration. Compensation is paid to those affected in civil claims against employers and (in the UK) in claims made under Social Security legislation rules for Prescribed Disease A11. Diagnostic tests have been proposed but most are not objective. The cold provocation test (CPT), which is objective, is often included in the evaluation of HAVS. METHODS: A continuous audit was made of the findings recorded at the 18 HAVS test centres in the UK established to evaluate miners. The audit, and its outcome, were monitored by the Medical Reference Panel who advise the Department of Trade and Industry. This audit report constitutes the second analysis of the findings relating to the CPT. RESULTS: The CPT, with measurement of digital rewarming times, is of no value in assessing vibration-induced damage to the hands. CONCLUSION: In its present format, the CPT should not be used for evaluating the vascular component of HAVS.

Hand-arm vibration syndrome from exposure to high-pressure hoses.

Hand-arm vibration syndrome has been reported in the literature to occur following exposure to vibration from the use of many tools, but to date there have been no case reports of its occurrence in workers who have used high-pressure hoses, alone or with other tools. To remedy this, the case histories of nine subjects (two without mixed exposure) examined in the UK and Canada are presented, together with their severity classified according to the Stockholm scales. Attention is drawn to the need to use multiple diagnostic tests to establish the diagnosis and the need to implement vibration isolation and damping methodologies, as and when feasible, with respect to hose nozzles in order to minimize the hazard. The ultimate goal for tool manufacturers, hygienists and engineers should be to reduce workplace vibration levels to meet national and international guidelines and legislation, including UK Health & Safety Executive guidelines and European Economic Community directives. The respective risk levels are presented, together with vibration measurements on hoses used by some of the cases.

How likely is it that Stockholm stage 1 of the hand arm vibration syndrome will progress to stages 2 and 3?

The progression of symptoms in the hand arm vibration syndrome (HAVS) is dependent on the interaction of individual and workplace factors. Workplace factors include type, magnitude and intermittency of exposure to hand transmitted vibration (HTV), anti-vibration tool design and workpiece characteristics. Individual susceptibility and constitutional factors are poorly understood and the reliance on anamnesis for diagnosis can lead to recall bias, inaccurate classification and an unreliable assessment of the stage of deterioration. This may be overcome by the adoption of multiple standardized testing. The introduction of a policy covering identification, risk assessment, health surveillance and reasonably practicable control measures will have the most significant impact on the incidence of new cases and deterioration in established cases.

Review of objective tests for the hand-arm vibration syndrome.

The Health and Safety Executive has recommended health surveillance for all workers in jobs identified as giving rise to significant risk of the hand-arm vibration syndrome. Objective tests are not routinely recommended for workplace surveillance but may have a role in the assessment of accurate staging or if decisions on an individual's continuing exposure is in question. This paper covers the use of multiple objective tests, the collection of routine data, a proposed scoring system for the sensorineural component and discusses the role of cold provocation testing in the diagnosis of the vascular component.