Lynch J; Krause N; Kaplan GA; Salonen R; Salonen JT. Workplace demands, economic reward, and progression of carotid atherosclerosis. Circulation 1997 Jul 1;96(1):302-7.
ABSTRACT:
BACKGROUND: Characteristics of the work environment have been
associated with cardiovascular morbidity and mortality, but it
is unclear whether these factors are associated with preclinical
manifestations of disease.
METHODS AND RESULTS: We investigated the association between job
demands, economic reward, and the 4-year progression of carotid
atherosclerosis in a population-based sample of 940 Finnish men.
Data from the Kuopio Ischemic Heart Disease Risk Factor Study
were used to estimate changes in plaque height, maximum and mean
intima-media thicknesses across combinations of job demands, and
income. Associations were examined in relation to atherosclerotic
risk factors and were stratified by baseline levels of atherosclerosis
and prevalent ischemic heart disease. Men who had jobs with high
demands and low economic rewards had significantly greater 4-year
progression of plaque height (0.33 mm, P = .008) and maximum intima-media
thickness (0.32, P = .03) than men with low-demand, high-income
jobs. The magnitude of these differences was not greatly attenuated
by risk factor adjustment and did not differ when examined by
the level of workplace resources, social support, or employment
status. Larger differences were observed in a subsample of men
who had more advanced atherosclerosis at baseline.
CONCLUSIONS: These results show that men with demanding work that
produces little economic reward have significantly greater progression
of carotid atherosclerosis than more advantaged men. The relationship
between job demands and health should be understood in a broad
framework of interacting economic conditions, social circumstances,
and behaviors that cascade over the life course and may ultimately
contribute to socioeconomic inequalities in morbidity and mortality.
Lynch J; Krause N; Kaplan GA; Tuomilehto J; Salonen JT. Workplace conditions, socioeconomic status, and the risk of mortality and acute myocardial infarction: the Kuopio Ischemic Heart Disease Risk Factor Study. Am J Public Health 1997 Apr;87(4):617-22.
ABSTRACT:
OBJECTIVES: This study investigated whether the association
between workplace conditions and the risk of all-cause and cardiovascular
mortality and acute myocardial infarction differed by socioeconomic
status.
METHODS: Prospective data were used to examine these associations
in 2297 Finnish men, with adjustment for prevalent diseases and
biological, behavioral, and psychosocial covariates, and stratified
by employment status and workplace social support.
RESULTS: Elevated age-adjusted relative hazards for all-cause
mortality were found for men who reported high demands, low resources,
and low income; high demands, high resources, and low income;
and low demands, high resources, and low income. Similar patterns
were found for cardiovascular mortality. In contrast, elevated
age-adjusted relative hazards for acute myocardial infarction
were observed only in men who reported high demands, low resources,
and low income. These results did not differ by level of workplace
social support or employment status.
CONCLUSIONS: The negative effects of workplace conditions on mortality
and of myocardial infarction risk depended on income level and
were largely mediated by known risk factors.
Krause N; Ragland DR; Greiner BA; Syme SL; Fisher JM. Psychosocial job factors associated with back and neck pain in public transit operators. Scand J Work Environ Health 1997 Jun;23(3):179-86.
ABSTRACT:
OBJECTIVES: This cross-sectional study examined associations
between psychosocial job factors and the prevalence of nondisabling
back and neck pain in professional drivers after physical work
load was taken into account.
METHODS: A total of 1449 transit vehicle operators completed a
medical examination and a questionnaire yielding information on
demographic and anthropometric variables, health status, and physical
and psychosocial job factors. Company records were used to supplement
information on employment history. Physical work load was measured
in life-time years and current weekly hours of professional driving.
The relation of psychosocial factors with back or neck pain was
analyzed by logistic regression models adjusted for past and current
physical work load, vehicle type, age, gender, body height, and
weight.
RESULTS: The main result of this study was that both physical
work load and psychosocial factors were simultaneously and independently
associated with back or neck pain. Psychosocial factors associated
with back or neck pain included extended uninterrupted driving
driving periods, frequency of job problems, high psychosocial
demands, high job dissatisfaction, and low supervisory support.
An analysis of specific job problems is provided which may be
useful in setting priorities for research and intervention efforts
in this high risk occupation.
CONCLUSION: The results provide support for the role of psychosocial
job characteristics in the etiology of back or neck pain in occupational
settings.
Ragland DR; Greiner BA; Krause N; Holman BL; Fisher JM. Occupational and nonoccupational correlates of alcohol consumption in urban transit operators. Preventive Medicine, 1995 Nov, 24(6):634-45.
ABSTRACT:
BACKGROUND. The influence of occupation and the worksite has
emerged as an important area of study in research on alcohol consumption.
Occupational and nonoccupational factors were studied in relation
to alcohol consumption using data from a 1983-1985 cross-sectional
study of transit operators.
METHODS. A total of 1.853 operators underwent a medical examination
for driver's license renewal (including information on age, ethnicity,
gender, education). Of these operators, 1,448 completed a questionnaire
about occupational (e.g., time of shift, job stressors) and nonoccupational
(e.g., personality, life stressors) factors. From either the medical
examination or the questionnaire, weekly alcohol consumption was
available for 1,820 operators. Variables related to alcohol consumption
in previous studies, or theoretically linked to consumption, were
analyzed in relation to heavy ( > or = 15 drinks/week) and
average weekly consumption.
RESULTS. Heavy and average consumption were both related to several
nonoccupational variables, including demographic (age, ethnicity,
gender, marital status), personality (depression, anger expression),
and life stress variables (i.e., life events). Heavy and average
consumption were also related to several occupational variables,
including job history (number of years driving, specific worksite)
and job stressors. Neither measure was related to subjective job
content (job demand, decision latitude).
CONCLUSIONS. Variability in consumption by demographic factors
among this population reflects that seen in society as a whole.
However, occupational factors may influence consumption, since
consumption was strongly related to (a) specific worksite and
time of shift and (b) reported job stressors. Clarifying the exact
influence of occupational and worksite factors on alcohol consumption
will depend on the convergence of findings from different research
designs (e.g., cross-sectional, longitudinal, ethnographic).
Krause N; Ragland DR. Occupational disability due to low back pain: a new interdisciplinary classification based on a phase model of disability. Spine 1994 May 1;19(9):1011-20.
ABSTRACT:
STUDY DESIGN. This study critically reviewed current conceptualizations
of occupational disability resulting from low back pain (LBP).
It proposes a new classification system for back pain built on
a phase-model of disability.
OBJECTIVES. The goal was to develop a classification system that
overcomes the shortcomings of existing classification schemes
and is useful for interdisciplinary research, prevention, treatment,
and rehabilitation.
SUMMARY OF BACKGROUND DATA. Attempts to study and prevent disability
resulting from LBP have been hampered by the use of inadequate
classifications of LBP.
METHODS. Current classifications of LBP were critically reviewed,
and criteria for a useful classification system are described.
The disabling process is organized in eight consecutive phases
determined by the presence and duration of work disability.
RESULTS. The proposed eight-phase classification is based primarily
on the presence and duration of work-disability rather than on
clinical categories. It takes into account the developmental and
social character of disability. The simplicity, reliability, and
expandability of the model allow for its interdisciplinary use
in research and intervention.
CONCLUSIONS. The prevention of disabling back pain requires an
interdisciplinary approach. For this purpose, other than purely
biomedical classifications of LBP are needed. The authors propose
an eight-phase classification system primarily based on the duration
of work disability and that takes into account other biomedical,
developmental, and social characteristics of work-disability resulting
from LBP.