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.
McKetney EC; Ragland DR. John Henryism, education, and blood pressure in young adults. The CARDIA study. Coronary Artery Risk Development in Young Adults Study. American Journal of Epidemiology, 1996 Apr 15, 143(8):787-91.
Wong O; Ragland DR; Marcero DH. An epidemiologic study of employees at seven pulp and paper mills. International Archives of Occupational and Environmental Health, 1996, 68(6):498-507.
ABSTRACT:
The cohort consisted of 11,178 Mead Corporation employees (9,358 males and 1,820 females) who had worked for at least one year between January 1, 1975 and December 31, 1992 at seven pulp and/or paper mills in the United States. The vital status of the cohort was determined through a variety of sources over an observation period of 17 years (1976-1992). Mortality data were analyzed in terms of cause-specific standardized mortality ratios (SMRs), with expected deaths based on U.S. national mortality rates. Job categories with similar exposures were created based on an historical exposure assessment. Mortality analyses were performed separately for total female and male employees. Among female employees, overall mortality was less than expected, and no significant cause-specific mortality excesses were observed. The small number of deaths among female employees did not permit further detailed analyses. Among male employees, statistically significant deficits from overall mortality (SMR = 69.0) and from all cancers (SMR = 71.3) were reported. In addition, low mortality risks for many specific causes were also observed, including many specific cancer sites, various types of cardiovascular diseases, and different forms of nonmalignant respiratory diseases. In particular, there was no mortality excess from lung cancer (SMR = 77.5), digestive cancer (SMR = 69.4), stomach cancer (SMR = 46.7), laryngeal cancer (no observed death), rectal cancer (SMR = 82.8). Hodgkin's lymphoma (no observed death), non-Hodgkin's lymphoma (SMR = 103.6), leukemia (SMR = 72.2), diabetes mellitus (SMR = 110.4), ischemic heart disease (SMR = 80.0), and nonmalignant respiratory diseases (SMR = 36.7). Furthermore, detailed analyses by length of employment, interval since hire (latency), and job category demonstrated no occupationally related mortality increases from any of the diseases examined. Specifically, based on internal comparisons, no upward trends in cause-specific mortality risk were observed by duration of employment. In conclusion, the results of this epidemiologic investigation demonstrated a favorable mortality experience for employees at the seven pulp and/or paper mills.
McKetney EC; Ragland DR. John Henryism, education, and blood pressure in young adults. The CARDIA study. Coronary Artery Risk Development in Young Adults Study. American Journal of Epidemiology, 1996 Apr 15, 143(8):787-91.
ABSTRACT:
John Henryism refers to an individual's self-perceived ability to meet the demands of the environment through hard work and determination. Prior research has shown that those with above average John Henryism but below average education (education being a measure of coping resources) had higher blood pressure levels than those with other combinations of John Henryism and education. The joint influence of John Henryism and education on blood pressure was examined among 4,986 black and white men and women, 18-30 years of age, from the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The combination of high John Henryism and low education was not associated with elevated systolic or diastolic blood pressure in any of the four groups defined by race and sex. However, the youthfulness of the population and the absence of a previously noted inverse association between education and blood pressure in this population draw into question the appropriateness of this setting to interpret the effect of John Henryism on the blood pressure-education relation.
Bucher HC; Ragland DR. Socioeconomic indicators and mortality from coronary heart disease and cancer: a 22-year follow-up of middle-aged men. American Journal of Public Health, 1995 Sep, 85(9):1231-6.
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.
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).
Winkleby MA; Ragland DR; Fisher JM; Syme SL. Excess risk of sickness and disease in bus drivers: a review and synthesis of epidemiological studies. Int J Epidemiol 1988 Jun;17(2):255-62.
ABSTRACT:
In an extensive search of available literature, 22 epidemiological studies that have examined health risks of bus drivers were identified. These studies focus on three main disease categories: (1) cardiovascular disease, including hypertension, (2) gastrointestinal illnesses, including peptic ulcer and digestive problems, and (3) musculoskeletal problems including back and neck pain. The studies consistently report that bus drivers have higher raes of mortality, morbidity, and absence due to illness when compared to employees from a wide range of other occupational groups. Increased disease rates have been found for drivers regardless of the use of different research methodologies, measurement techniques and comparison groups. When evaluating the impact of bias on the estimates of risk, it appears likely that findings are conservative: strong systematic selective factors have probably favoured the elimination of those in poorer health both at the time of entry into and exit from the job of bus driving and other sources of bias have most likely caused underestimations of risk. Nevertheless, there remain questions that need careful assessment before firm conclusions can be made about whether increased disease rates result from driving a bus. Such questions, coupled with the consistent findings of heightened risk of disease, make urban bus drivers an appropriate and promising occupational group in which to study further the potential adverse effects of the work environment on employee health.
Winkleby MA; Ragland DR; Syme SL; Fisher JM. Heightened risk of hypertension among black males: the masking effects of covariables. Am J Epidemiol 1988 Nov;128(5):1075-83.
ABSTRACT:
This study examines the extent to which a set of 10 demographic, behavioral, and medical risk factors explain black/white differences in hypertension. Data are from a cross-sectional examination of San Francisco transit drivers aged 25-65 years surveyed during 1983-1985 as part of an occupational health study. The inherent restriction of the study population to bus drivers and the further restriction to males in this population (764 blacks and 224 whites) controlled for factors related to occupation and sex. Control of 10 additional potential risk factors, including age, education, body mass index, smoking, and intake of caffeine and alcohol was possible in the analytic phase of the study. The unadjusted prevalence of hypertension (systolic blood pressure greater than or equal to 140 mmHg, diastolic blood pressure greater than or equal to 90 mmHg, or current use of anti-hypertensive medications) was 36.1 per cent for black males compared with 30.8 per cent for white males. The greatest difference in prevalence was observed for black males aged 55-64 years, for whom the prevalence was 46 per cent higher than for white males the same age. Despite higher rates of hypertension, blacks in all age groups exhibited lower levels of most major risk factors for hypertension. As a result, the independent effect of race on hypertension was increased rather than attenuated when the 10 covariables were taken into account (odds ratio of 1.27 in the unadjusted analysis, increasing to 1.54 in the adjusted, multivariate analysis). That this set of risk factors did not explain the higher rates of hypertension among blacks suggests that racial differences may arise from as yet unrecognized environmental and/or individual factors. The results also indicate that the association between race and blood pressure may have been underestimated in past studies that have relied on unadjusted analyses, in which negative confounding or masking effects of covariables have not been considered.
Ragland DR; Winkleby MA; Schwalbe J; Holman BL; Morse L; Syme SL; Fisher JM. Prevalence of hypertension in bus drivers. Int J Epidemiol 1987 Jun;16(2):208-14.
ABSTRACT:
This paper reports the results of a cross-sectional study conducted to evaluate the prevalence of hypertension in 1500 black and white male bus drivers from a large urban transit system in the US. Data for this study were compiled from the files of an occupational health clinic which conducts biennial medical examinations for drivers' license renewal. To test whether prevalence of hypertension was higher among bus drivers than among employed individuals in general, drivers were compared to three groups: individuals from both a national and local health survey and individuals undergoing baseline health examinations prior to employment as bus drivers. After adjustment for age and race, hypertension rates for bus drivers were significantly greater than rates for each of the three comparison groups. These findings support previous results from international studies of bus drivers suggesting that exposure to the occupation of driving a bus may carry increased health risk. This research has expanded into an on-going study which has the goals of clarifying the extent of hypertension in bus drivers and identifying specific behavioural and occupational factors that may be responsible for increased risk of cardiovascular disease.