A prospective study of morbidity patterns in a petroleum refinery and chemical plant.

This study examined the morbidity experience from 1981 to 1988 of a prospective cohort of 3422 refinery and petrochemical plant employees from the Shell Deer Park manufacturing complex. The morbidity data for this study, which include all illness and absence records in excess of five days, were extracted from the morbidity section of the Shell health surveillance system. Standardised morbidity ratios (SMRs) of disease prevalence in this cohort were calculated using an internal comparison group of all manufacturing employees of the Shell Oil Company. Among production employees, the overall morbidity was statistically significantly higher (SMR = 109) than that of the comparison group. Illness due to hypertension (SMR = 144), haemorrhoids (SMR = 149), diseases of the nervous system (SMR = 120), respiratory system (SMR = 108), and digestive system (SMR = 117) were also raised for this group. The increased risk due to these medical conditions does not appear to be associated with occupational factors. Lymphatic and haematopoietic tissue neoplasms were raised (SMR = 124), but were based on only four cases.

Morbidity patterns among employees at a petroleum refinery.

This study examined the morbidity experience of a prospective cohort of 2132 male employees who worked at a petroleum refinery from 1981 through 1988. The morbidity data included all illness-absence episodes in excess of 5 days during the study period. Standardized morbidity ratios (SMRs) of disease prevalence were calculated using data from all manufacturing employees of the Shell Oil Company as an internal comparison group. As such, there is no potential bias associated with the "healthy worker effect" in this type of study design. Morbidity for all causes combined was virtually the same as that for the comparison group with 2,311 observed and 2,318 expected disease prevalence events. However, there were statistically increased prevalence of musculoskeletal system disorders (SMR = 136) and injuries (SMR = 125) among staff employees and skin and subcutaneous tissue disorders (SMR = 138) among production employees. A review of the original morbidity reports for these skin conditions revealed that none were due to exposure to chemical products or solvents. The SMR for neoplasms of the lymphatic and hematopoietic tissue among production employees was slightly elevated but was based on only three cases (2.4 expected). Of the three cases, none was due to leukemia.

The relationship between work-related and non-work-related injuries.

A case-control study of occupational injuries sustained by 914 male hourly workers employed in two Tenneco manufacturing divisions in 1987 was undertaken to examine the association between occupational and non-occupational injuries. Its aim was to evaluate whether employees who experienced a work-related injury were more likely to have sustained a previous non-work-related injury compared to individuals who did not experience a work-related injury. A statistically significant association between occupational injuries and past non-occupational injuries was seen when all workers compensation (WC) claims were analyzed (OR = 1.41) and when claims involving indemnity for lost time were analyzed (OR = 1.82). In addition, both workers who had occupational low-back injuries and workers who had occupational non-low-back injuries also had significantly higher risks of such injuries from a non-occupational origin (OR = 1.91 for low-back injuries and OR = 1.44 for non-low-back injuries). The findings suggest that elements other than workplace hazards (such as life-style and physical and psychological factors) may predispose an individual to both occupational and non-occupational injuries.

Health care utilization and costs for injury in a corporate setting.

This article presents the incidence and costs for non-work-related injuries among 15,408 employees and their families based on health insurance claims data analysis. The treatment of injuries accounted for 11.3% of the plan's total health care costs ($31 million) for the 1986 policy year. For adults, women had a higher incidence rate than men; but for children, males had a higher incidence rate than females. A disproportionately high share of claims and charges for adults were attributed to low back disorders. Hospital admissions, length of stay and hospital days per 1,000 persons were similar for males and females, but much higher for adults than for children. This article provides an example of the utility of health insurance claims data as a source of morbidity information for disease surveillance and epidemiologic research. The analysis of claims data can be seen as a prerequisite to the development of preventive programs aimed at reducing injury rates and health care costs for injuries in a corporate setting.

Prospective morbidity surveillance of Shell refinery and petrochemical employees.

Results for a prospective morbidity study of 14,170 refinery and chemical workers from 1981 through 1988 are presented. Illness/absence data for this study were extracted from the morbidity section of the Shell Health Surveillance System which includes records of all illness/absences in excess of five days. Age adjusted annual morbidity frequency rates and annual durations of absence are presented by age, sex, job, and work status. Generally, rates and durations of absence were highest for older age groups, women, and production workers. Increased risk was associated with the presence of known disease risk factors. Overall, 48% of the employees had at least one illness/absence in excess of five days during the eight year period. Twelve per cent of the employees had four or more absences, which accounted for 54% of the total number of absences and 52% of the total work days lost. Among men, the five most common conditions accounted for 72% of all illness/absences. In descending order they were injuries (25%), respiratory illnesses (17%), musculoskeletal disorders (14%), digestive illnesses (9%), and heart disease (7%). Similar patterns were noted among women. These findings may be useful in setting priorities and directing efforts such as health education programmes and other strategies for the prevention of disease.

A cost-effectiveness evaluation of primary health care projects for the poor.

A cost-effectiveness analysis was conducted to determine the relative efficacy of nine primary health care projects serving low income persons in urban and rural areas of Texas. The projects were created as part of a government program to provide services in medically underserved areas of the state by contracting with local public and private providers. While they vary widely in terms of sponsoring organizations, service strategy, and scope of services, the projects share a similar goal of providing an array of basic medical and preventive care services to the poor. This study compares the average cost per encounter for diagnosis/treatment, emergency, family planning, and preventive health screening services provided by the various projects during the first year of operation. After adjusting for differences in input prices and patient volume, the cost differences are examined and related to organizational model and personnel mix. Those projects with the highest ratio of nonphysician to physician practitioners proved more cost-effective, as did those projects following the public clinic model of service delivery.

Incidence and cost of injury in an industrial population.

Using both occupational (workers' compensation) and non-occupational (group health insurance) data, the nature and magnitude of injuries were determined in a working population of 20,705. Approximately one third of the population sustained an injury in 1986 (the year of study). Men experienced a significantly higher injury rate than women (33.3 per 100 v 24.9 per 100) and hourly employees had significantly higher incidence rates than salaried employees (42.0 per 100 v 22.5 per 100). The majority of nonoccupational injury claims were for low back disorders, whereas most occupational injury claims were related to superficial wounds and contusions. Overall, the incidence of nonoccupational injuries (21.1 per 100) was twofold higher than that of occupational injuries (10.8 per 100). Total costs for occupational and nonoccupational injuries were $4.97 million. The per-capita costs were $120 for both nonoccupational and occupational injuries. However, if only health care expenses are included in this calculation, nonoccupational injury costs would be almost 3 times as high as occupational injury costs ($120 v $46). These findings argue for increasing the share of corporate resources for off-the-job injury prevention programs aimed at reducing injury incidence and resultant health care costs.