A social epidemiologic perspective on health and illness places
greater importance than do traditional approaches on the impact
of social factors (e.g., class and gender) in health and illness.
The focus shifts for occupational diseases to the organization
of work and the production of workplace stressors which act on
the individual --- eliciting cognitive processes that result in
physiological disturbance (e.g., depression and hypertension).
In contrast, the traditional biomedical model often conceptualizes
illness as occurring as the result of disruption of psychological
and/or physical processes wherein subjective behaviors and personality
factors (e.g., neuroticism) are of primary importance (i.e., disease
proceeds from the individual to the environment). This latter
perspective views the work environment as tolerable to the vast
majority of humans except where there is a lack of fit between
the individual and their environment.
With the introduction of the Job Strain (Demand-Control) Model
in 1979 a hypothesis was presented which identified workplace
psychosocial stressors that are "chronic, not initially life-threatening
and the product of sophisticated human organizational decision
making. In decision making the controllability of the stressor
is critical, and it becomes more important as increasingly complex
and integrated social organizations develop, with ever more complex
limitations on individual behavior". (Karasek 1979) Job
strain occurs when the human organism is overloaded psychologically
and at the same time deprived of control over his or her work
environment, a combination which is predicted to give rise to
increased risk of stress-related illness (Karasek 2000). The
consequences of chronic exposure to job strain can be severe as
seen, for example, in the findings of the Cornell University Worksite
Ambulatory Blood Pressure Project wherein job strain has been
shown to increase the risk of hypertension three to five fold.
Recently, other workplace psychosocial variables have been identified
including "effort-reward" imbalance which defines deleterious
job conditions as a "mismatch between high workload (high
demand) and low control over long-term rewards" (Siegrist
etal, 1990). A number of studies have examined "threat-avoidant"
vigilant work, i.e., work that involves continuously maintaining
a high level of vigilance in order to avoid disaster, such as
loss of human life (Belkic et al.,2000c); long work hours (e.g.,
Falger & Schouten, 1992 ); and the impact of shift work (Steenland,
2000) have also been investigated.
Psychological health outcomes parallel the findings for hypertension
and CVD with a number of abnormal mental health states being associated
with exposure to workplace stressors. These include a relationship
between job strain and anxiety and depression, as well as burnout.
From the social epidemiologic perspective these psychological
states are frequently seen as mediators between psychosocial stressors
and mental and physical health outcomes.
The implications for the organization of work and for professional
practitioners arising from this social epidemiologic perspective
include;
1) The recognition of that between 20 and 30% of cases of hypertension
among working men could be prevented by eliminating exposure to
job strain.
2) That work-related hypertension has been greatly under-estimated
because of reliance upon blood pressure measurement taken in the
clinic setting which is far removed from working life.
3) That current trends in working life characterized by a rising
level of exposure to job strain and long and irregular work hours,
portend that work-related hypertension and IHD will become an
increasingly important problem in the years to come
4) That it is possible to design work that promotes health and
well-being; it is not demanding work per se that is harmful, but
work without control over how one meets the job demands or uses
one's skills.