A cohort study evaluating the risk of stroke associated with long-term exposure to ambient fine particulate matter in Taiwan.

BACKGROUND: Evidences have shown that the stroke risk associated with long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5) varies among people in North America, Europe and Asia, but studies in Asia rarely evaluated the association by stroke type. We examined whether long-term exposure to PM2.5 is associated with developing all strokes, ischemic stroke and hemorrhagic stroke. METHODS: The retrospective cohort study consisted of 1,362,284 adults identified from beneficiaries of a universal health insurance program in 2011. We obtained data on air pollutants and meteorological measurements from air quality monitoring stations across Taiwan in 2010-2015. Annual mean levels of all environmental measurements in residing areas were calculated and assigned to cohort members. We used Cox proportional hazards models to estimate hazard ratio (HR) and 95% confidence interval (CI) of developing stroke associated with 1-year mean levels of PM2.5 at baseline in 2010, and yearly mean levels from 2010 to 2015 as the time-varying exposure, adjusting for age, sex, income and urbanization level. RESULTS: During a median follow-up time of 6.0 years, 12,942 persons developed strokes, 9919 (76.6%) were ischemic. The adjusted HRs (95% CIs) per interquartile range increase in baseline 1-year mean PM2.5 were 1.03 (1.00-1.06) for all stroke, 1.06 (1.02-1.09) for ischemic stroke, and 0.95 (0.89-1.10) for hemorrhagic stroke. The concentration-response curves estimated in the models with and without additional adjustments for other environmental measurements showed a positively linear association between baseline 1-year mean PM2.5 and ischemic stroke at concentrations greater than 30 µg/m3, under which no evidence of association was observed. There was an indication of an inverse association between PM2.5 and hemorrhagic stroke, but the association no longer existed after controlling for nitrogen dioxide or ozone. We found similar shape of the concentration-response association in the Cox regression models with time-varying PM2.5 exposures. CONCLUSION: Long-term exposure to PM2.5 might be associated with increased risk of developing ischemic stroke. The association with high PM2.5 concentrations remained significant after adjustment for other environmental factors.

Feasibility of using urinary TDGA as a biomarker for VCM exposures.

Thiodiglycolic acid (TDGA) is a major metabolite of vinyl chloride monomer (VCM), and it has been suggested as an exposure biomarker for VCM. The validity of this biomarker when the level of VCM is less than 5 ppm, however, is questionable. The objective of this article is to evaluate the feasibility of using urinary TDGA as a biomarker of VCM exposure in a community health risk assessment setting where the concentration of VCM in air is typically very low (likely below 1 ppm). To achieve this objective, we examine the fraction of urinary TDGA associated with different levels of VCM exposures of three studies from different countries, using estimations of the TDGA metabolite predicted by a PBPK model. It is demonstrated that differences in background TDGA have considerable effect on the adequacy of TDGA as a biomarker of VCM. We conclude that, in a community health assessment setting, TDGA should not be used as an exposure biomarker for VCM without having a proper control group, and a PBPK model can be used first to determine whether or not the amount of TDGA in urine is of concern.

Acute Bronchitis and Bronchiolitis Infection in Children with Asthma and Allergic Rhinitis: A Retrospective Cohort Study Based on 5,027,486 Children in Taiwan.

This study evaluated the risks of childhood acute bronchitis and bronchiolitis (CABs) for children with asthma or allergic rhinitis (AR). Using insurance claims data of Taiwan, we identified, from children of ≤12 years old in 2000-2016, cohorts with and without asthma (N = 192,126, each) and cohorts with and without AR (N = 1,062,903, each) matched by sex and age. By the end of 2016, the asthma cohort had the highest bronchitis incidence, AR and non-asthma cohorts followed, and the lowest in the non-AR cohort (525.1, 322.4, 236.0 and 169.9 per 1000 person-years, respectively). The Cox method estimated adjusted hazard ratios (aHRs) of bronchitis were 1.82 (95% confidence interval (CI), 1.80-1.83) for the asthma cohort and 1.68 (95% CI, 1.68-1.69) for the AR cohort, relative to the respective comparisons. The bronchiolitis incidence rates for these cohorts were 42.7, 29.5, 28.5 and 20.1 per 1000 person-years, respectively. The aHRs of bronchiolitis were 1.50 (95% CI, 1.48-1.52) for the asthma cohort and 1.46 (95% CI, 1.45-1.47) for the AR cohort relative to their comparisons. The CABs incidence rates decreased substantially with increasing age, but were relatively similar for boys and girls. In conclusion, children with asthma are more likely to develop CABs than are children with AR.

Roles of Ambient Temperature and PM2.5 on Childhood Acute Bronchitis and Bronchiolitis from Viral Infection.

Studies have associated the human respiratory syncytial virus which causes seasonal childhood acute bronchitis and bronchiolitis (CABs) with climate change and air pollution. We investigated this association using the insurance claims data of 3,965,560 children aged ≤ 12 years from Taiwan from 2006−2016. The monthly average incident CABs increased with increasing PM2.5 levels and exhibited an inverse association with temperature. The incidence was 1.6-fold greater in January than in July (13.7/100 versus 8.81/100), declined during winter breaks (February) and summer breaks (June−August). The highest incidence was 698 cases/day at <20 °C with PM2.5 > 37.0 µg/m3, with an adjusted relative risk (aRR) of 1.01 (95% confidence interval [CI] = 0.97−1.04) compared to 568 cases/day at <20 °C with PM2.5 < 15.0 µg/m3 (reference). The incidence at ≥30 °C decreased to 536 cases/day (aRR = 0.95, 95% CI = 0.85−1.06) with PM2.5 > 37.0 µg/m3 and decreased further to 392 cases/day (aRR = 0.61, 95% CI = 0.58−0.65) when PM2.5 was <15.0 µg/m3. In conclusion, CABs infections in children were associated with lowered ambient temperatures and elevated PM2.5 concentrations, and the high PM2.5 levels coincided with low temperature levels. The role of temperature should be considered in the studies of association between PM2.5 and CABs.

Childhood Rotavirus Infection Associated with Temperature and Particulate Matter 2.5 µm: A Retrospective Cohort Study.

No study has ever investigated how ambient temperature and PM2.5 mediate rotavirus infection (RvI) in children. We used insurance claims data from Taiwan in 2006-2012 to evaluate the RvI characteristics in children aged ≤ 9. The RvI incidence rates were higher in colder months, reaching the highest in March (117.0/100 days), and then declining to the lowest in July (29.2/100 days). The age-sex-specific average incident cases were all higher in boys than in girls. Stratified analysis by temperature (<20, 20-24, and ≥25 °C) and PM2.5 (<17.5, 17.5-31.4, 31.5-41.9, and ≥42.0 µg/m3) showed that the highest incidence was 16.4/100 days at average temperatures of <20 °C and PM2.5 of 31.5-41.9 µg/m3, with Poisson regression analysis estimating an adjusted relative risk (aRR) of 1.26 (95% confidence interval (CI) = 1.11-1.43), compared to the incidence at the reference condition (<20 °C and PM2.5 < 17.5 µg/m3). As the temperature increased, the incident RvI cases reduced to 4.84 cases/100 days (aRR = 0.40, 95% CI = 0.35-0.45) when it was >25 °C with PM2.5 < 17.5 µg/m3, or to 9.84/100 days (aRR = 0.81, 95% CI = 0.77-0.93) when it was >25 °C with PM2.5 > 42 µg/m3. The seasonal RvI is associated with frequent indoor personal contact among children in the cold months. The association with PM2.5 could be an alternative assessment due to temperature inversion.

Cancer mortality in workers exposed to dieldrin and aldrin: over 50 years of follow up.

OBJECTIVE: Dieldrin and aldrin, pesticides widely used until the 1970s, have been under suspicion of being carcinogenic. In this study, overall and cause-specific mortality was assessed in a cohort of 570 employees occupationally exposed to the pesticides dieldrin and aldrin to investigate the long-term health effects, in particular carcinogenic effects. METHODS: All of the employees worked in the production plants between January 1954 and January 1970 and were followed for cause-specific mortality until 30 April 2006. Based on dieldrin levels in blood samples taken from 343 workers during the exposure period, the total intake of dieldrin was estimated for each individual subjects in the cohort. The estimated total intake ranged from 11 to 7,755 mg of dieldrin, with an average of 737 mg. RESULTS: Two hundred and twenty-six workers had died before 30 April 2006 compared with an expected number of 327.3, giving a standardized mortality ratio (SMR) of 69.0 (95% confidence interval (CI): 60.3-78.7). Overall cancer mortality was also significantly lower than expected (SMR: 76.4, 95% CI: 60.8-94.9). Also, none of the specific cancer sites showed a significant excess mortality and no association between exposure level and cancer mortality was found. CONCLUSION: The results from this study support findings from other epidemiological and recent animal studies concluding that dieldrin and aldrin are not likely human carcinogens.

The impact of obesity on illness absence and productivity in an industrial population of petrochemical workers.

PURPOSE: Examine employee illness absence and the economic impact of overweight and obesity in a petrochemical industry workforce. METHODS: A 10-year follow-up (1994-2003) of 4153 Shell Oil Company employees was conducted. Absence frequency rates and average number of workdays lost were calculated for normal weight, overweight, and obese employees with and without the presence of additional risk factors. The study also assessed the change in overweight and obesity prevalence in the study population and estimated the current and future economic impact of these conditions. RESULTS: Overall, obese employees were 80% more likely to have absences (24.0 vs. 13.3 per 100 employees) and were absent 3.7 more days (7.7 vs. 4.0 days) per year compared with those employees with normal body weights. Among employees with no additional risk factors, overweight employees lost more than 1.5 times more days (4.2 vs. 2.6 days) per year, and obese employees more than 2.5 times more days (7.2 vs. 2.6 days) compared with their normal-weight colleagues. Similarly, absence frequency attributable to cardiovascular disease significantly increased among employees with one or two additional risk factors present, such as smoking, high blood pressure, or hypercholesterolemia. The direct cost of illness absence from overweight and obesity for this study population was $1,873,500. Furthermore, 31% of the total illness absence was attributable to overweight and obesity in 1994, and the percentage had risen to 36% by 2003. CONCLUSIONS: The economic impact to employers is great and will continue to rise unless measures are taken, particularly to reduce the number of employees moving from overweight to obesity with time.

A 56-year mortality follow-up of Texas petroleum refinery and chemical employees, 1948-2003.

OBJECTIVE: To further investigate the mortality risk of employees who worked in the petroleum refinery industry, we updated an earlier investigation by extending the mortality follow-up by an additional 14 years through 2003. METHODS: The cohort consisted of 10,621 employees with an average follow-up of 34 years. We used the standardized mortality ratio (SMR) adjusted for age, race, and calendar years as a measure of risk. RESULTS: Overall mortality (SMR=0.77, 95% confidence interval [CI], 0.74-0.79), all cancer mortality (SMR=0.87, 95% CI=0.82-0.93), and most cause-specific mortalities for the total study population were lower than or similar to that of the population of Harris County, Texas. This study did not show a significant increase in leukemia in the total population or in any of the subgroups. The only statistically significant excess of mortality found in this study was an increase in mesothelioma among maintenance employees; the SMR was 4.78 (95% CI=2.54-8.17) among employees who worked for a minimum of one year and was 7.51 (95% CI=3.75-13.45) among those with 10 or more years of employment and 20 or more years of latency. CONCLUSIONS: After more than half a century of follow-up, employees at this facility continue to show more favorable mortality outcomes than the general local population. Overall, no statistically significant increase of leukemia or of any of the specific cell types was found. The increased mesothelioma is likely related to past exposure to asbestos.

Exploring the relationships between diabetes and smoking: with the development of glucose equivalent concept for diabetes management.

The extent of interaction between smoking and diabetes has been under-appreciated. Smokers had more diabetes, and when diabetes patients smoke, the combined mortality effect was greater than either the addition or multiplication of these two medical problems. Patients seen in the office are usually more interested in reducing blood glucose than in quitting smoking, and yet, smoking caused mortality risks, at a magnitude similar to or more than diabetes. The concept of "glucose equivalent of smoking" was developed to direct more attention to smoking in clinical management. Based on the follow-up observations from a large Asian cohort, the risk of an individual who smokes, from all-cause mortality, was found to be equivalent to an elevation of blood glucose by an average of 41mg/dl for the cohort in general and 68mg/dl for the diabetes in particular. By relating the message of smoking hazards in terms of "glucose equivalent", clinicians will be more alerted to counsel and patients will be more likely to quit. Appreciating this concept has a potential to change the paradigm of diabetes management, to bridge the clinical disconnect between the two, and to provide new ammunition for the diabetes epidemic in Taiwan.

Obesity and mortality in a prospective study of a middle-aged industrial population.

BACKGROUND: Although obesity is an established risk factor for coronary heart disease and stroke mortality, its role as a risk factor for other causes of death has not been extensively investigated, particularly in an industrial population. METHODS: This prospective mortality study included 20 years of follow up of middle-aged industrial workers (n = 7139) at Shell Oil Company's manufacturing and research facilities. Baseline health risk factor data as of December 31, 1983, and mortality data as of December 31, 2003, were extracted from the company's Health Surveillance System. Relative risks (RRs) for selected causes of death by body mass index (BMI) category were calculated using the Cox proportional hazards model adjusted for age, sex, and smoking status as well as other potential risk factors, ie, cholesterol, hypertension, and fasting blood glucose. RESULTS: Compared with employees with BMI between 18.5 and 24.9 kg/m, those with BMI of 30 kg/m or greater had a statistically increased RR (adjusted for age, sex, and smoking status) for all causes (RR, 1.25; 95% confidence interval [CI] = 1.03-1.51), coronary heart diseases (RR, 2.29; 95% CI = 1.50-3.50), cardiovascular diseases (RR, 2.22; 95% CI = 1.51-3.27), diabetes (RR, 16.97; 95% CI = 2.11-136.44), and accidental deaths (RR, 2.64; 95% CI = 1.23-5.66). After adjusting for additional covariates, coronary heart diseases and cardiovascular diseases remained statistically significant. CONCLUSIONS: Obesity was associated with increased death rates for all causes, cardiovascular diseases, diabetes, and all accidents. Overweight individuals had a statistically lower cancer rate. Death rates for lung cancer and respiratory disease were lower among overweight/obese employees but did not reach statistical significance. Reductions of employee obesity can be an effective means of reducing these causes of death.

Impact of a disability management program on employee productivity in a petrochemical company.

BACKGROUND: An inhouse disability management program was implemented to reduce nonoccupational absences in a petrochemical corporation. The program was administered by full-time certified, corporate-based case managers and nine manufacturing location nurses. METHODS: Employees were required to report all absences on the first day and again on the fourth workday of absence. A medical certification form was required for absences of 4 or more working days. Extended absences were actively managed. An Internet-based case management tool, Medgate, was used as a primary management tool. RESULTS: Results were compared with the previous year among the target population and with company business units not participating in the program. The program resulted in a 10% reduction in total absence days per employee (6.9 to 6.2) compared with the previous year, whereas business units not using the program had an 8% increase (5.5 to 5.9). This disability management program resulted in a more than four to one return on investment based on direct expenditures and cost savings in terms of reduced absence days. CONCLUSIONS: The inhouse disability management program was successful by absence duration, employee satisfaction, and return on investment criteria.

Illness absence patterns among employees in a petrochemical facility: impact of selected health risk factors.

BACKGROUND: Illness absence in a working population is a complex phenomenon and can be influenced by many factors, such as age, gender, and personal health risk factors. The current study used prospectively collected employee health risk and morbidity data to examine illness absence patterns for a working population and to quantify the impact of selected health risk factors on employee illness absence. METHODS: The study population consisted of 2550 regular employees working at a Texas petrochemical facility. Morbidity data were extracted from the company's Health Surveillance System, and records of absences were derived from personnel and payroll systems. The morbidity frequency rate and average duration of absence per employee per year were calculated by age, gender, and selected health risk factors, including smoking, body mass index, cholesterol, triglycerides, hypertension, and fasting glucose. RESULTS: Morbidity frequency rates and average duration of absence increased with age and with the presence of health risk factors. The absence frequency rate increased with an increase in the number of risk factors present from no risk factors (11.8 per 100 employees) to four or more risk factors (32.3 per 100 employees). The number of workdays lost also increased with the number of risk factors present, with the least number of workdays lost by employees with zero risk factors (4.1 day), followed by one (6.4 days), two (8.8 days), three (9.3 days), and four or more risk factors (12.6 days). CONCLUSIONS: The impact of employee health risk factors has been shown in this study to be associated with absence frequency and duration of absence. Reduction in employee health risk factors can be an effective means of improving employees' health and increasing a company's productivity.

Cancer incidence among refinery and petrochemical employees in Louisiana, 1983-1999.

PURPOSE: The purpose of this study is to determine the incidence of cancer among employees at two petrochemical facilities in south Louisiana, and to compare their cancer rates to those of the general population of south Louisiana. METHODS: Records on 4639 active and former employees and retirees from the two plants were linked to the Louisiana Tumor Registry (LTR) database by LTR staff to ascertain incident cases of cancer. Standardized incidence ratios (SIRs) were then calculated using the south Louisiana population as the comparison and adjusted for age, race, and time period. RESULTS: There was a significant 16% deficit of overall cancer cases for males in this cohort (SIR=0.84; 95% CI, 0.74-0.95). The only significantly elevated SIR in males was for cancer of the bone and joint (SIR=6.89; 95% CI, 1.42-20.1). This result was based on three non-fatal cases of bone cancer with different histologies, occurring in different parts of the body. These cases worked in different units of one plant. Significant deficits were seen for lung cancer, non-Hodgkin's lymphoma, and cancer of the oral cavity and pharynx. Cancer incidence among 719 female employees was non-significantly increased (SIR=1.24; 95% CI, 0.81-1.82). Breast cancer accounts for the excess (SIR=1.46; 95% CI, 0.73-2.61). Seventy percent of the breast cancer cases worked in an office setting. CONCLUSIONS: This study found little evidence of any association between cancer incidence and employment at these two petrochemical facilities. The increased incidence of bone cancer is unlikely to be due to occupational exposures. The non-significant excess of breast cancer may be due to early detection or other important unmeasured confounders, such as certain reproductive factors.

Bridging the gap in life expectancy of the aborigines in Taiwan.

BACKGROUND: Similar to the general population in Taiwan, the health of aborigines has steadily improved over the last 30 years, but the gap remains wide, especially in males, despite an infusion of substantial medical resources. The objectives of this study are to quantify the contribution of major causes of death to the gap in life expectancy and to propose initiatives to bridge the health gap between aborigines and the general population. METHODS: This study included residents (slightly over 200000) from 30 'aboriginal townships' in Taiwan. The gap in life expectancy between aborigines and the general population was analysed by decomposing these gaps according to major causes of deaths. This analysis quantifies the contribution of different causes of deaths to the gap in life expectancy between the two populations. RESULTS: The overall mortality of aborigines in these townships was approximately 70% higher than the respective male and female general populations over the past 30 years. Mortality from infectious disease, cirrhosis of the liver, accidents, and suicide are substantially higher than the general population. The gap in life expectancy at birth in males was 8.5 years during 1971-1973, increasing to 13.5 years by 1998-2000, however, the gap in females remained relatively stable (8.0 years and 8.4 years, respectively). Of the 13.5-year difference in life expectancy in males, the differential mortality from diseases of the digestive system (mainly due to cirrhosis of the liver), accidents (from both motor vehicle and non-motor vehicle accidents), and infectious and parasitic disease contributed half (50%) of the gap in life expectancy. In females, the above primarily preventable causes of deaths accounted for 41% of the life expectancy gap. CONCLUSIONS: Based on the findings of this study, we suggest that future focus should be in the area of primary prevention in order to reduce the incidence of infectious and parasitic diseases, liver cirrhosis, and accidents.

Controlling cigarette smoking in the workplace in Taiwan: opportunities and challenges.

Cigarette smoking is one of the most serious health problems in Taiwan. Although the Taiwanese government passed a Tobacco Hazard Control Act in 1997, it is not fully applicable to the workplace. The purpose of the study was to review workplace smoking prevalence and policies, and to discuss the opportunities and challenges of implementing workplace smoking policies in Taiwan. Results show that smoking prevalence in the workplace in Taiwan is high, particularly among males, ranging from 38 to 68%. More than 75% of smokers in Taiwan smoke in the workplace. The percentage of workplaces implementing restrictive smoking policies in Taiwan is low, particularly in small-sized workplaces. The Tobacco Hazard Control Act in Taiwan has not been strongly enforced in public places, let alone in private companies. Several constructive suggestions are presented in the study. For example, establishing workplace smoking policies, informing employers that second-hand smoke is a human carcinogen, providing financial support for employers to initiate cessation programs, and modifying the current Tobacco Hazard Control Act, etc.

Ten years' experience using an integrated workers' compensation management system to control workers' compensation costs.

This work presents 10 years of experience using an Integrated Workers' Compensation Claims Management System that allows safety professionals, adjusters, and selected medical and nursing providers to collaborate in a process of preventing accidents and expeditiously assessing, treating, and returning individuals to productive work. The hallmarks of the program involve patient advocacy and customer service, steerage of injured employees to a small network of physicians, close follow-up, and the continuous dialogue between parties regarding claims management. The integrated claims management system was instituted in fiscal year 1992 servicing a population of approximately 21,000 individuals. The system was periodically refined and by the 2002 fiscal year, 39,000 individuals were managed under this paradigm. The frequency of lost-time and medical claims rate decreased 73% (from 22 per 1000 employees to 6) and 61% (from 155 per 1000 employees to 61), respectively, between fiscal year 1992 and fiscal year 2002. The number of temporary/total days paid per 100 insureds decreased from 163 in fiscal year 1992 to 37 in fiscal year 2002, or 77%. Total workers' compensation expenses including all medical, indemnity and administrative, decreased from $0.81 per $100 of payroll in fiscal year 1992 to $0.37 per $100 of payroll in fiscal year 2002, a 54% decrease. More specifically, medical costs per $100 of payroll decreased 44% (from $0.27 to $0.15), temporary/total, 61% (from $0.18 to $0.07), permanent/partial, 63% (from $0.19 to $0.07) and administrative costs, 48% ($0.16 to $0.09). These data suggests that workers' compensation costs can be reduced over a multi-year period by using a small network of clinically skilled health care providers who address an individual workers' psychological, as well as physical needs and where communication between all parties (e.g., medical care providers, supervisors, and injured employees) is constantly maintained. Furthermore, these results can be obtained in an environment in which the employer pays the full cost of medical care and the claimant has free choice of medical provider at all times.

Simulating the impact of changing trends in smoking and obesity on productivity of an industrial population: an observational study.

OBJECTIVE: To estimate the impact of trends in smoking and obesity prevalence on productivity loss among petrochemical employees from 1980 to 2009. METHODS: Smoking and obesity informations were collected during company physical examinations. Productivity loss was calculated as differential workdays lost between smokers and non-smokers, and obese and normal-weight employees. RESULTS: During 1980-2009, smoking prevalence decreased from 32% to 17%, while obesity prevalence increased from 14% to 42%. In 1982, lost productivity from obesity was an estimated 43 days/100 employees, and for smoking, 65 days/100 employees, but by 1987, workdays lost due to obesity exceeded that attributable to smoking. In 2007, workdays lost from obesity were 3.7 times higher than for smoking. CONCLUSIONS: Owing to the increasing trend in obesity, the productivity impact on employers from obesity will continue to rise without effective measures supporting employee efforts to achieve healthy weight through sustainable lifestyle changes.

Risk factors for illness absence due to musculoskeletal disorders in a 4-year prospective study of a petroleum-manufacturing population.

OBJECTIVES: To quantify risk factors for nonoccupational absence from musculoskeletal disorders (MSD) among petroleum-manufacturing employees. METHODS: We conducted a 4-year follow-up study including 860 employees with an MSD illness absence of 4 days or longer and 5691 employees with no MSD absence. Odds ratios were calculated using logistic regression. RESULTS: Risk of MSD absence from low back and non-low back disorders was significantly associated with physically demanding job, overweight/obesity, prior absence from MSD, and absence from cardiovascular, respiratory, or mental illness, or accidents during the study period. Smoking also increased risk of low back disorders. CONCLUSIONS: Results suggest it is possible to reduce the impact of MSD through integrated safety prevention and health promotion programs including traditional elements of job factor evaluation, training, and ergonomics, but also health counseling and support for weight reduction, smoking cessation, and personal fitness programs.

The Shell Disability Management Program: a five-year evaluation of the impact on absenteeism and return-on-investment.

OBJECTIVE: To evaluate the impact of the Shell Disability Management Program (DMP) on U.S. manufacturing employee absenteeism. METHODS: We estimated absence episodes and days lost per employee from 2004 to 2008 compared to pre-program values in 2002, and productivity gains from transitional duty (TD). RESULTS: Between 2002 and 2008, absence episodes/100 employees decreased from 37.4 to 25.7 among hourly workers but increased from 9.7 to 13.1 among staff employees. Days lost per employee decreased from 7.4 to 5.2 for hourly employees and were virtually unchanged for staff employees. TD resulted in 6042 days saved in 2006 and 11,438 days in 2008, with direct cost savings of more than $4.1 million from 2006 to 2008. CONCLUSIONS: The Shell DMP emphasizes absence tracking, timely return-to-work, and facilitation of TD. Absenteeism decreased significantly after DMP implementation, particularly among hourly employees, with an estimated 2.4:1 return-on-investment.

Combined impact of health risk factors on mortality of a petroleum industry population.

OBJECTIVE: To assess the combined impact of health risk factors on mortality. METHODS: A 21-year mortality follow-up of 12,896 Shell Oil Company employees was conducted. Relative risks of mortality, expressed as hazard ratios, in relation to the six risk factors, including cigarette smoking, obesity, high blood pressure, total cholesterol, serum glucose, and triglycerides, were calculated using a Cox proportional hazards model. RESULTS: Employees with health risk factors had higher mortality rates for all-causes combined and for cardiovascular diseases compared to employees without such risk factors. Smoking, obesity, hypercholesterolemia, and hyperglycemia independently and significantly predicted cardiovascular disease mortality. Mortality risks from all causes and from cardiovascular disease increased with the number of risk factors present. CONCLUSIONS: This study found a positive association between several health risk factors and mortality. A greater number of risk factors corresponded to a higher rate of death. Reductions of employee health risk factors may be an effective means of improving employees' long-term health.