Know the difference between all the HAVS Tiers (1-5)
Posted By Stephanie Hancox on 2017-12-13 09:36
Multiple studies have shown that regular and frequent exposure to vibration can lead to permanent adverse health effects, which are most likely to occur when contact with a vibrating tool or work process is a regular and significant part of a person’s job.
Hand-arm vibration can cause a range of conditions collectively known as hand-arm vibration syndrome (HAVS), as well as specific diseases such as white finger or Raynaud’s syndrome, carpal tunnel syndrome and tendinitis. Vibration syndrome has adverse circulatory and neural effects in the fingers. The signs and symptoms include numbness, pain, and blanching (turning pale and ashen). Also known as vibration white finger, it has been estimated by the HSE that there are 288,000 sufferers in the UK. (Read more on HAVS here)
So what are the Tiers and how do they differ?...
HAVS Tier 1- Is an initial assessment in the form of a self-assessment questionnaire. This should be completed by any new or existing employee prior to exposure to vibrating tools. This questionnaire includes questions on the individual's medical history, prior use of vibrating tools, and is used as a baseline for all further assessments in regards to HAVS. If no existing possible symptoms of HAVS are identified, the individual is assumed to be fit for work, however, if anything flags up, they should be referred to an occupational health nurse for a face to face HAVS Tier 3 assessment. Prior to completing the initial questionnaire, the employee should be given sufficient information on HAVS and possible health consequences linked to exposure to vibrating tools.
HAVS Tier 2- Similar to HAVS Tier 1, the Tier 2 is again a self-assessment questionnaire which should be repeated on an annual basis. The HSE recommends that a responsible person is appointed to be able to convey the risks of exposure to vibrating tools, and address any concerns of an employee, have a thorough understanding of the health surveillance HOWEVER they are not qualified to give a diagnosis of HAVS and as such should refer any given information to the occupational health provider.
Similar again to the Tier 1 questionnaire; if any possible symptoms are flagged up on the questionnaire, then the employee should be referred to HAVS Tier 3 to be seen by an OH Nurse for further assessment/s. If no symptoms are Flagged, then the employee should be considered fit for work until the next annual surveillance. However; an employee should not wait until the 12-month assessment to report any issues or possible symptoms of HAVS.
HAVS Tier 3- Is a face-to-face assessment with an OH Nurse trained in HAVS (or a suitably trained OH Doctor), which is usually conducted following any reported concerns in HAVS tier 1/2. Again, a questionnaire is also completed although the Tier 3 questionnaire is based more on personal medical history, family history, activities conducted in and out of work areas and any prescribed medication. The reason for these questions is to help identify that if the employee is diagnosed with HAVS, whether it has been caused via work activities or out of work activities.
Along with the questionnaire, a brief clinical examination also takes place which assesses both the vascular and neurological function in both the hands and arms to assess any damage caused in relation to HAVS. It is also advised to have a brief musculoskeletal assessment, along with a grip test and manual dexterity.
After the OH Nurse and/or qualified OH Physician have reviewed both the questionnaire and results from the health surveillance, a presumptive diagnosis is recorded, along with advice on whether the employee is fit for working with vibrating tools, if a change in job role is advised or a further referral onto HAVS Tier 4 is required.
HAVS Tier 4 - is again a face-to-face assessment with an Occupational Health Physician and is when the formal prognosis of whether the employee has HAVS. If the diagnosis is given, the employer is given the precise description of HAVS as written in the “The control of vibration at work regulations. “
The OH Physician will use information gathered previously in regards to present symptoms and will consider these in their decision on the HAVS diagnosis and their report and recommendations.
HAVS Tier 5 - Unlike the previous Tiers, Tier 5 is completely optional and through the use of a selection of the below tests, an investigation is taken to identify the original cause/s of HAVS. If testing is undertaken, the employee must note that the OH Physician can over-ride previous diagnosis dependent on the results of the tests carried out within Tier 5.
Tests which can be carried out within Tier 5 includes:
Vascular Tests - Finger re-warming after cold provocation test (CPT) (Measures the timing. However, factors such as the emotional state of the individual can alter the results; due to the sympathetic nervous system, having a large influence.)
- Finger Systolic Blood Pressure Test (FSBP) (Within the Digital Arteries)
Sensorineural - Vibrotactile Perception Threshold
- Thermal (Temperature) Perception Threshold (TPT)
"Some researchers using the standardized test methods are concerned about the repeatability of the CPT in control subjects, i.e. abnormal (positive) results can appear in repeat tests in individuals with no history of symptoms of Raynaud’s disease or HAVS. Other reservations have been expressed about the robustness of the FSBP test. Currently, there is no consensus among UK testing practitioners on a vascular test that is sufficiently robust to be recommended for diagnosis of HAVS in a worker undergoing health surveillance. " http://www.hse.gov.uk/vibration/hav/advicetoemployers/havocchealth.pdf
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