Work ability after the diagnosis of hand-arm vibration syndrome

Introduction
Exposure to hand-arm vibration (HAV) may cause white fingers, tingling and numbness of fingers and musculoskeletal disorders of upper extremities. These symptoms comprise so called hand-arm vibration syndrome (HAVS). The aim of this study was to assess the prognosis of HAVS and consequences of HAVS on patients' future work ability and social welfare.

Methods
All cases of HAVS diagnosed at the Finnish Institute of Occupational Health (FIOH) 1990-2008 were gathered. In 2010, a questionnaire on current symptoms, employment status and work ability was sent to all these patients (n=241). Altogether 149 patients (62 %) returned the questionnaire.

Results
The mean age of the patients was 50.7 years at the time of the diagnosis and 59.3 years at the time of the questionnaire. Of the respondents, 56 (37%) were currently employed, 46 (31%) were on disability pension and 27 (18%) were retired because of old age. Altogether 52 respondents (36%) reported less finger blanching than before diagnosis and for 93 respondents (63%) symptoms were the same or more frequent. Self-estimated work ability, physical working capacity and quality of life (EQ-5D) were significantly lower in patients whose vascular or sensorineural symptoms were the same or worse than before diagnosis. Also, the patients whose symptoms remained or worsened were less likely to believe they could still work in the same job after two years. Age did not explain the differences. The longer the exposure time had been, the more permanent were the symptoms.

Discussion
The disability caused by HAVS may easily be underestimated, but this study shows that all types of symptoms of HAVS worsened the working capacity of the patients significantly. Both before and after the diagnosis of HAVS, preventive measures should be taken more actively to support the patients to continue their working career.