[Multivariate analysis on subjective symptoms in forestry workers using chain saw].
This study was conducted to evaluate the relationship between the prevalence of subjective symptoms in workers using vibrating tools and the duration of chain saw operation and to examine whether the symptoms were relevant to factors other than the usage of vibrating tools. The statistical model of multivariate analysis was adapted to analyze individual data on the subjective symptoms of 317 chain saw operators. The obtained results were as follows: 1. In analysis of covariance, age-adjusted operating year in workers with peripheral circulatory, peripheral neurological and musculoskeletal disturbances was significantly longer than that without such disturbances. For these disturbances, partial regression coefficients of operating year were significantly high in multiple regression analysis. These results show that these disturbances and age-adjusted operating year are mutually closely related. 2. Multiple regression analysis showed that the partial regression coefficients of both operating year and age were low for nine symptoms, i.e. dulling sense of touch, joint pain, headache, dizziness and/or tinnitus, profuse sweating, discomfort of stomach, palpitation and/or dyspnea, hearing disturbance and lumbago. These results suggest that such symptoms were not related to either age or chain saw operation. 3. The results of principal component analysis were visualized in three-dimensional space in order to evaluate the relationships among the symptoms. The analysis showed that peripheral circulatory and neurological disturbances appeared independently and that general symptoms such as easy fatigability, headache, forgetfulness, vertigo and/or tinnitus, easy irritability, sleep disorder, profuse sweating, discomfort of stomach, palpitation and/or dyspnea, shoulder stiffness, hearing disturbance and lumbago consisted of four independent groups. Each group has no relationship with duration of chain saw operation. This suggests other harmful factors of the groups play a role in the prevalence of the symptoms.
Nagase
H
H
Department of Public Health, School of Medicine, Kanazawa University.
Nakamura
H
H
Nakamura
H
H
Nohara
S
S
Miura
K
K
Ohnishi
T
T
D000367:Age Factors; D016468:Forestry; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D014732:Vibration / Q000009:adverse effects*