KAROSHI: DEATH FROM OVERWORK
What Is Karoshi?
Karoshi is a Japanese word which means death from overwork. The
phenomenon was first identified in Japan, and the word is being
adopted internationally (Drinkwater 1992). Uehata (1978) reported
17 karoshi cases at the 51st annual meeting of the Japan Association
of Industrial Health. Among them seven cases were compensated as
occupational diseases, but ten cases were not. In 1988 a group of
lawyers established the National Defense Counsel for Victims of
Karoshi (1990) and started telephone consultation to handle inquiries
about karoshi-related workers' compensation insurance. Uehata (1989)
described karoshi as a sociomedical term that refers to fatalities
or associated work disability due to cardiovascular attacks (such
as strokes, myocardial infarction or acute cardiac failure) which
could occur when hypertensive arteriosclerotic diseases are aggravated
by a heavy workload. Karoshi is not a pure medical term. The media
have frequently used the word because it emphasizes that sudden
deaths (or disabilities) were caused by overwork and should be compensated.
Karoshi has become an important social problem in Japan.
Research on Karoshi
Uehata (1991a) conducted a study of 203 Japanese workers (196 males
and seven females) who had cardiovascular attacks. They or their
next of kin consulted with him regarding workers' compensation claims
between 1974 and 1990. A total of 174 workers had died; 55 cases
had already been compensated as occupational disease. A total of
123 workers had suffered strokes (57 arachnoidal bleedings, 46 cerebral
bleedings, 13 cerebral infarctions, seven unknown types); 50, acute
heart failure; 27, myocardial infarctions; and four, aortic ruptures.
Autopsies were performed in only 16 cases. More than half of the
workers had histories of hypertension, diabetes or other atherosclerotic
problems. A total of 131 cases had worked for long hours-more than
60 hours per week, more than 50 hours overtime per month or more
than half of their fixed holidays. Eighty-eight workers had identifiable
trigger events within 24 hours before their attack. Uehata concluded
that these were mostly male workers, working for long hours, with
other stressful overload, and that these working styles exacerbated
their other lifestyle habits and resulted in the attacks, which
were finally triggered by minor work-related troubles or events.
Karasek Model and Karoshi
According to the demand-control model by Karasek (1979), a high-strain
job-one with a combination of high demand and low control (decision
latitude)-increases the risk of psychological strain and physical
illness; an active job-one with a combination of high demand and
high control-requires learning motivation to develop new behaviour
patterns. Uehata (1991b) reported that the jobs in karoshi cases
were characterized by a higher degree of work demands and lower
social support, whereas the degree of work control varied greatly.
He described the karoshi cases as very delighted and enthusiastic
about their work, and consequently likely to ignore their needs
for regular rest and so on-even the need for health care. It is
suggested that workers in not only high-strain jobs but also active
jobs could be at high risk. Managers and engineers have high decision
latitude. If they have extremely high demands and are enthusiastic
in their work, they may not control their working hours. Such workers
may be a risk group for karoshi.
Type A Behaviour Pattern in Japan
Friedman and Rosenman (1959) proposed the concept of Type A behaviour
pattern (TABP). Many studies have showed that TABP is related to
the prevalence or incidence of coronary heart disease (CHD).
Hayano et al. (1989) investigated
the characteristics of TABP in Japanese employees using the Jenkins
Activity Survey (JAS). Responses of 1,682 male employees of a telephone
company were analysed. The factor structure of the JAS among the
Japanese was in most respects equal to that found in the Western
Collaborative Group Study (WCGS). However, the average score of
factor H (hard-driving and competitiveness) among the Japanese was
considerably lower than that in the WCGS.
Monou (1992) reviewed TABP
research in Japan and summarized as follows: TABP is less prevalent
in Japan than in the United States; the relationship between TABP
and coronary heart disease in Japan seems to be significant but
weaker than that in the US; TABP among Japanese places more emphasis
on "workaholism" and "directivity into the group"
than in the US; the percentage of highly hostile individuals in
Japan is lower than in the US; there is no relationship between
hostility and CHD.
Japanese culture is quite different from those of Western countries. It is strongly influenced
by Buddhism and Confucianism. Generally speaking, Japanese workers
are organization centred. Cooperation with colleagues is emphasized
rather than competition. In Japan, competitiveness is a less important
factor for coronary-prone behaviour than job involvement or a tendency
to overwork. Direct expression of hostility is suppressed in Japanese
society. Hostility may be expressed differently than in Western
Working Hours of Japanese
It is well known that Japanese workers work long hours compared
with workers in other developed industrial countries. Normal annual
working hours of manufacturing workers in 1993 were 2,017 hours
in Japan; 1,904 in the United States; 1,763 in France; and 1,769
in the UK (ILO 1995). However, Japanese working hours are gradually
decreasing. Average annual working hours of manufacturing employees
in enterprises with 30 employees or more was 2,484 hours in 1960,
but 1,957 hours in 1994. Article 32 of the Labor Standards Law,
which was revised in 1987, provides for a 40-hour week. The general
introduction of the 40-hour week is expected to take place gradually
in the 1990s. In 1985, the 5-day work week was granted to 27% of
all employees in enterprises with 30 employees or more; in 1993,
it was granted to 53% of such employees. The average worker was
allowed 16 paid holidays in 1993; however, workers actually used
an average of 9 days. In Japan, paid holidays are few, and workers
tend to save them to cover absence due to sickness.
Why do Japanese workers work such long hours? Deutschmann (1991) pointed out three structural
conditions underlying the present pattern of long working hours
in Japan: first, the continuing need of Japanese employees to increase
their income; second, the enterprise-centred structure of industrial
relations; and third, the holistic style of Japanese personnel management.
These conditions were based on historical and cultural factors.
Japan was defeated in war in 1945 for the first time in history.
After the war Japan was a cheap wage country. The Japanese were
used to working long and hard to earn their subsistence. As labour
unions were cooperative with employers, there have been relatively
few labour disputes in Japan. Japanese companies adopted the seniority-oriented
wage system and lifetime employment. The number of hours is a measure
of the loyalty and cooperativeness of an employee, and becomes a
criterion for promotion. Workers are not forced to work long hours;
they are willing to work for their companies, as if the company
is their family. Working life has priority over family life. Such
long working hours have contributed to the remarkable economic achievements
National Survey of Workers' Health
The Japanese Ministry of Labour conducted surveys on the state of
employees' health in 1982, 1987 and 1992. In the survey in 1992,
12,000 private worksites employing 10 or more workers were identified,
and 16,000 individual workers from them were randomly selected nationwide
based on industry and job classification to fill out questionnaires.
The questionnaires were mailed to a representative at the workplace
who then selected workers to complete the survey.
Sixty-five per cent of these workers complained of physical fatigue due to their usual
work, and 48% complained of mental fatigue. Fifty-seven per cent
of workers stated that they had strong anxieties, worries or stress
concerning their job or working life. The prevalence of stressed
workers was increasing, as the prevalence had been 55% in 1987 and
51% in 1982. The main causes of stress were: unsatisfactory relations
in the workplace, 48%; quality of work, 41%; quantity of work, 34%.
Eighty-six per cent of these worksites conducted periodic health examinations. Worksite
health promotion activities were conducted at 44% of the worksites.
Of these worksites, 48% had sports events, 46% had exercise programmes
and 35% had health counselling.
National Policy to Protect
and Promote Workers' Health
The purpose of the Industrial Safety and Health Law in Japan is
to secure the safety and health of workers in workplaces as well
as to facilitate the establishment of a comfortable working environment.
The law states that the employer shall not only comply with the
minimum standards for preventing occupational accidents and diseases,
but also endeavour to ensure the safety and health of workers in
workplaces through the realization of a comfortable working environment
and the improvement of working conditions.
Article 69 of the law, amended in 1988, states that the employer shall make continuous
and systematic efforts for the maintenance and promotion of workers'
health by taking appropriate measures, such as providing health
education and health counselling services to the workers. The Japanese
Ministry of Labour publicly announced guidelines for measures to
be taken by employers for the maintenance and promotion of workers'
health in 1988. It recommends worksite health promotion programmes
called the Total Health Promotion Plan (THP): exercise (training
and counselling), health education, psychological counselling and
nutritional counselling, based on the health status of employees.
In 1992, the guidelines for the realization of a comfortable working environment were announced
by the Ministry of Labour in Japan. The guidelines recommend the
following: the working environment should be properly maintained
under comfortable conditions; work conditions should be improved
to reduce the workload; and facilities should be provided for the
welfare of employees who need to recover from fatigue. Low-interest
loans and grants for small and medium-sized enterprises for workplace
improvement measures have been introduced to facilitate the realization
of a comfortable working environment.
The evidence that overwork causes sudden death is still incomplete.
More studies are needed to clarify the causal relationship. To prevent
karoshi, working hours should be reduced. Japanese national occupational
health policy has focused on work hazards and health care of workers
with problems. The psychological work environment should be improved
as a step towards the goal of a comfortable working environment.
Health examinations and health promotion programmes for all workers
should be encouraged. These activities will prevent karoshi and