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.

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.

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.

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.

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.

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.

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.

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.

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.

Age at retirement and long term survival of an industrial population: prospective cohort study.

OBJECTIVE: To assess whether early retirement is associated with better survival. DESIGN: Long term prospective cohort study. SETTING: Petroleum and petrochemical industry, United States. SUBJECTS: Past employees of Shell Oil who retired at ages 55, 60, and 65 between 1 January 1973 and 31 December 2003. MAIN OUTCOME MEASURE: Hazard ratio of death adjusted for sex, year of entry to study, and socioeconomic status. RESULTS: Subjects who retired early at 55 and who were still alive at 65 had a significantly higher mortality than those who retired at 65 (hazard ratio 1.37, 95% confidence interval 1.09 to 1.73). Mortality was also significantly higher for subjects in the first 10 years after retirement at 55 compared with those who continued working (1.89, 1.58 to 2.27). After adjustment, mortality was similar between those who retired at 60 and those who retired at 65 (1.06, 0.92 to 1.22). Mortality did not differ for the first five years after retirement at 60 compared with continuing work at 60 (1.04, 0.82 to 1.31). CONCLUSIONS: Retiring early at 55 or 60 was not associated with better survival than retiring at 65 in a cohort of past employees of the petrochemical industry. Mortality was higher in employees who retired at 55 than in those who continued working.

A hematology surveillance study of petrochemical workers exposed to 1,3 butadiene.

Complete blood counts (CBC) have been recognized as an easy and readily available screen for hematotoxicity following occupational exposure to 1,3-butadiene. This study evaluated hematology data from employees who have ever participated in the Shell Butadiene Medical Surveillance Program (BMSP), compared with employees who have not participated. This study examined potential hematopoietic toxicity in relation to the occupational exposures at two Shell facilities. This study included 404 employees who participated in the BMSP, with mean butadiene exposure (TWA-8, TWA-10, and TWA-12 together) of 4.55 ppm from 1979-1996 and 0.25 ppm from 1997-2003, and 773 comparison employees. The comparison group included employees not participating in either the benzene or butadiene surveillance programs. Abnormality of six CBC parameters, including white blood cell count, red blood cell count, lymphocyte count, hemoglobin concentration, mean corpuscular volume and platelet count, and the adjusted mean values of these parameters in the exposed group were compared with those of the comparison group. We found no significantly increased abnormality for any hematology parameter among exposed employees. The adjusted mean values (adjusted for age, sex, race, length of time between first and last exam, current smoking status, and first exam value) of the exposed employees were similar to those in the comparison group. At current occupational exposure levels for 1,3-butadiene, there is no evidence of adverse hematological effects observed in this study. These findings are consistent with results of three similar studies in the literature.

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.

Workplace smoking policies in Taiwan and their association with employees' smoking behaviours.

BACKGROUND: The implementation of worksite smoking policies has shown significant effects on reducing employees' smoking consumption and protecting non-smoking workers. However, there are no data about workplace smoking policies in Taiwan. The purpose of this study was to document the status of worksite smoking policies in Taiwan and its potential impact on employees' smoking behaviours. METHODS: A two-stage investigation was conducted. The first stage was to examine the current status of workplace smoking policies and the second was to evaluate the relationship between workplace smoking policies and employees' smoking behaviours. After two follow-ups in each stage, 264 companies and 1141 employees returned their questionnaires. RESULTS: Workplace smoking policies were associated with types of businesses and size of workplaces. Only approximately half of manufacturing and service companies have implemented a prohibitive smoking policy. Large facilities (>750 employees) were more likely to implement a prohibitive policy (57%). Employees in workplaces with a prohibitive policy had lower prevalence of smoking and cigarette consumption, and less exposure to passive smoking. Although most smokers agreed with banning smoking in their work environment, no difference in interest in participating in cessation programs was found. CONCLUSIONS: Significant associations were found between workplace smoking policies and employees' smoking behaviours. Results of the study provide basic information for designing more refined smoking policies in the workplace in Taiwan.