A Study of the Impact of Occupational and Domestic Factors on Insomnia among Industrial Workers of a Manufacturing Company in Japan

Abstract

Insomnia is one of the most common health problems and has recently been re-termed 'Disorders of initiating and Maintaining Sleep', or DIMS. The main purpose of the present study was to investigate the relationship between daily psychosocial stressors, to which workers are exposed in occupational and/or private life, and insomnia among male industrial 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 completed the questionnaire (average age was 40.9 years old). Twenty seven point seven per cent of the subjects complained of insomnia in the last month prior to the survey and the prevalence was in general accord with 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 demonstrated that four psychosocial factors were significantly associated with insomnia: i.e. VDT work overload (odds ratio [OR] 5.058; 95% confidence intervals [95% CI] 2.381-10.745), limited space of bedroom (OR 2.612; 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; CI 1.77-5.719).

Sleep Problems in White-Collar Male Workers in an Electric Equipment Manufacturing Company in Japan.

“…Moreover, factors such as age and occupation may affect the prevalence of sleep problems. Aging is a well known factor in the disturbance of sleep; a higher prevalence rate of sleep problems in older workers has been observed in previous studies 8,14,17) . And some occupations have been observed to show higher prevalence rates than others 18) .…”

“…Studies on sleep in working populations have therefore been mainly focused on low quality of sleep in shift or night workers. Yet, over 70% of the working population of most industrialized countries including Japan are working in daytime 13) , and it has been reported in previous epidemiological studies that about 25-30% of daytime workers have problems with sleep 4,14,16) , indicating that these problems in day workers are also an important occupational health problem. However, only a few studies have investigated the prevalence of sleep problems in daytime working populations 8,[14][15][16][17] , including two reports from Japan 14,15) .…”

“…Yet, over 70% of the working population of most industrialized countries including Japan are working in daytime 13) , and it has been reported in previous epidemiological studies that about 25-30% of daytime workers have problems with sleep 4,14,16) , indicating that these problems in day workers are also an important occupational health problem. However, only a few studies have investigated the prevalence of sleep problems in daytime working populations 8,[14][15][16][17] , including two reports from Japan 14,15) . One of these reports 14) suggests that the prevalence of sleep problems (27.7%) in Japanese daytime white-collar workers is similar to that reported in studies in other countries 8,16) ; on the other hand, another study 15) indicated a lower (7.1%) prevalence rate.…”

“…However, only a few studies have investigated the prevalence of sleep problems in daytime working populations 8,[14][15][16][17] , including two reports from Japan 14,15) . One of these reports 14) suggests that the prevalence of sleep problems (27.7%) in Japanese daytime white-collar workers is similar to that reported in studies in other countries 8,16) ; on the other hand, another study 15) indicated a lower (7.1%) prevalence rate. The conflicting findings suggest a need for further investigation to clarify the reasons for the differences in the prevalence rates as well as factors associated with them.…”

“…The conflicting findings suggest a need for further investigation to clarify the reasons for the differences in the prevalence rates as well as factors associated with them. One reason for the differences could be the definition of sleep problems since various definitions were used in previous studies 8,[14][15][16][17] . Moreover, factors such as age and occupation may affect the prevalence of sleep problems.…”