A STUDY OF THE IMPACT OF OCCUPATIONAL AND DOMESTIC FACTORS ON INSOMNIA AMONG INDUSTRIAL-WORKERS OF A MANUFACTURING COMPANY IN JAPAN

Insomnia is one of th most common health problems and has recently bee n re-termed 'Disorders of Initiating and Maintaining Sleep', or DIMS. The main purpose of the present study was to investigate the relations hip between daily psychosocial stressors, to which workers are exposed in occupational and/or private life, and insomnia among male industri al workers in a medium-sized company located in Nagasaki City, Japan. All of the workers in the company (n = 368, male = 319) were asked to answer six sleep related questions and 24 questions about working and private conditions. Two hundred and seventy-one (85.0%) of them comple ted the questionnaire (average age was 40.9 years old). Twenty seven p oint seven per cent of the subjects complained of insomnia in the last month prior to the survey and the prevalence was in general accord wi th previous surveys. On the other hand, the proportion of hypnotic use (1.1%), especially in insomniac group (2.7%) was lower than previous reports. The results of multiple logistic regression analysis demonstr ated that four psychosocial factors were significantly associated with insomnia: i.e. VDT work overload (odds ratio [OR] 5.058; 95% confiden ce intervals [95% CI] 2.381-10.745), limited space of bedroom (OR 2.61 2; 95% CI 1.283-5.683), over-involvement in job (OR 2.78; 95% CI 1.188 -6.540), frequent alcohol beverages consumption (OR 2.595; 95% CI 1.17 7-5.719).