The role of personal risk factors in the occurrence of the hand-arm vibration syndrome: a pooled analysis of individual data from Italian cross-sectional and cohort studies.

PURPOSE

To investigate the role of personal risk factors in the occurrence of the vascular, neurological and fibroproliferative disorders of the hand-arm vibration syndrome (HAVS) in workers groups exposed to hand-transmitted vibration (HTV).

METHODS

HAVS prevalence and incidence data were pooled across a series of cross-sectional studies (total sample: 1272 HTV workers, 579 controls) and prospective cohort studies (total sample: 377 HTV workers, 138 controls) conducted in Central and North-Eastern Italy. The pooled studies included detailed individual-level information about HTV exposure, personal risk factors, medical comorbidities and HAVS disorders. Vibration exposures were evaluated according to the recommendations of ISO standards.

RESULTS

The pooled studies revealed dose-response relationships between HTV exposure and the vascular and neurological components of HAVS. Older age, excessive alcohol intake, and comorbid conditions such as metabolic disorders, traumas/surgery to the neck and upper limbs, and disorders of the cervical spine were differentially associated with HAVS outcomes. Higher BMI had a protective effect on vascular disorders. Data modelling showed no significant interactions between HTV exposure and personal risk factors in the occurrence of upper limb disorders.

CONCLUSIONS

The pooled analysis of epidemiological studies with individualised work, personal, and medical data confirmed that HTV exposure is a primary occupational risk factor for disorders in the fingers and hands of users of vibratory tools. Ageing and some personal factors connected to lifestyles and comorbidities were associated with an increased risk for upper limb disorders in HTV workers. Occupational and personal risk factors tended to contribute independently of each other to adverse outcomes in operators of hand-held vibrating machinery.