BackgroundThe aim of this study was to investigate whether self-reports of work ability correlated to the results of quantitative tests measuring physical capacity and a questionnaire assessing psychological mood in vibration-exposed patients with hand symptoms.MethodsThe participants comprised 47 patients (36 men and eleven women) with exposure to hand vibration and vascular and/or neurological symptoms in the hands. They performed several quantitative tests (manual dexterity, hand grip strength, finger strength) and completed the Work Ability Index (WAI) and Hospital Anxiety and Depression Scale (HADS) questionnaires.ResultsCorrelation analysis revealed statistically significant associations between the WAI results, the HADS indices, hand grip and finger strength, and manual dexterity measured using the Purdue Pegboard®. Multiple regression analysis revealed age and HADS indices as the strongest predictors of work ability.ConclusionsThe patient’s age and psychological mood may be stronger predictors of work ability compared with results from tests measuring physical capacity of the hands in vibration-exposed patients with hand symptoms. When using the WAI as an instrument for assessing work ability in these patients, health care providers need to be more aware of the impact of the psychological mood.

A prospective cohort study investigating an exposure-response relationship among vibration-exposed male workers with numbness of the hands by Edlund M, Burström L, Gerhardsson L, Lundström R, Nilsson T, Sandén H, Hagberg M This study on hand-arm-vibration (HAV) exposed workers spanned 16 years; exposure dose was assessed for each individual; and the study may contribute to knowledge about an exposure-response relationship between neurological symptoms and HAV exposure. Furthermore, to our knowledge, there are no other studies reporting incidence of numbness in hands among HAV-exposed workers or how it affects work performance. Affiliation 203Original article Scand J Work Environ Health. 2014;40(2):203-209. doi:10.5271/sjweh.3386 A prospective cohort study investigating an exposure-response relationship among vibration-exposed male workers with numbness of the hands Objective The aim of this study was to investigate the exposure-response relationship of hand-arm vibration (HAV) exposure to neurological symptoms (numbness) of the hand in a cohort of vibration-exposed workers. MethodsThe baseline cohort comprised 241 office and manual workers with and without exposure to HAV.Numbness (the symptom or event) in the hand was assessed for all subjects at baseline and follow-ups after 5, 10, and 16 years. The workers were stratified into quartiles with no exposure in the first quartile and increasing intensity of exposure in quartiles 2-4 (groups 1-3). Data analysis was performed using survival analysis (time-to-event). Information on cumulative exposure and years of exposure to event was collected via questionnaires. Measurements were performed in accordance with the International Organization for Standardization (ISO) 5349-1. ResultsThe hazard ratio (HR) of risk of event (numbness) differed statistically significantly between the nonexposed group (group 0) and the two higher exposure groups (groups 2 and 3). There was also a significant ratio difference between the lowest exposure group (group 1) and the two higher groups. The ratio for group 1 was 1.77 [95% confidence interval (95% CI) 0.96-3.26] compared with 3.78 (95% CI 2.15-6.62) and 5.31 (95% CI 3.06-9.20) for groups 2 and 3, respectively. ConclusionThe results suggest a dose-response relationship between vibration exposure and numbness of the hands. This underlines the importance of keeping vibration levels low to prevent neurological injury to the hands.

Objectives The aim of the present study was to investigate the possible increase in hand tremor in relation to hand-arm vibration (HAV) exposure in a cohort of exposed and unexposed workers.MethodsParticipants were 178 male workers with or without exposure to HAV. The study is cross-sectional regarding the outcome of tremor and has a longitudinal design with respect to exposure. The dose of HAV exposure was collected via questionnaires and measurements at several follow-ups. The CATSYS Tremor Pen® was used for measuring postural tremor. Multiple linear regression methods were used to analyze associations between different tremor variables and HAV exposure, along with predictor variables with biological relevance.ResultsThere were no statistically significant associations between the different tremor variables and cumulative HAV or current exposure. Age was a statistically significant predictor of variation in tremor outcomes for three of the four tremor variables, whereas nicotine use was a statistically significant predictor of either left or right hand or both hands for all four tremor variables.ConclusionsIn the present study, there was no evidence of an exposure–response association between HAV exposure and measured postural tremor. Increase in age and nicotine use appeared to be the strongest predictors of tremor.