Mortality in a Cohort of Patients with Vibration Syndrome in Japan

Abstract

Mortality in a Cohort of Patients with Vibration Syndrome in Japan: Yoshiharu FUKUDA, et al. Health Promotion, Department of International Health Development, Division of Public Health, Graduate School of Tokyo Medical and Dental University-To evaluate the mortality of patients certified to be suffering from vibration syndrome in the Kyushu region of Japan, the cohort consisting of 838 vibration syndrome patients who had worked at local forestry offices was followed up. A total of 15, 208 person-yrs of follow-up data from 1966 to 1996 was analyzed. The mortality of the population of Kumamoto Prefecture, a central part of Kyushu region, was used to estimate the expected number. Standardized mortality ratios (SMRs) and 95% confidence intervals (95% Cls) for specific causes were calculated. 208 deaths were observed. The mortality from all causes was similar between in the cohort studied and in the general population. The remarkable differences were seen in leukemia (SMR 370, 95% Cl 227-1000) and suffocation (SMR 269, 95% Cl 140 to 518). The excess mortality from leukemia in the cohort studied is likely due to exposure to wood dust or gasoline during forestry work and Human T-cell Leukemia Virus type I infection. The increased mortality from suffocation is possibly attributable to suicide.