A longitudinal study of adult-onset asthma incidence among HMO members

Occupational Contributions to Respiratory Health Disparities

Occupation is an important contributor to disparities in respiratory disease, affecting financial status, health-care access, and exposure to hazardous substances. Although occupation and associated exposures are included in the socioecological models, work exposures remain persistently absent from research on health inequities and their contribution to health. This article focuses on the occupational contribution to disparities in asthma, chronic obstructive pulmonary disease, silicosis, coronavirus disease 2019, and lung cancer. Because occupational exposures are largely preventable through proper workplace controls, the recognition of occupational causes of disease can provide an opportunity for interventions to bring about health equity.

Cardiovascular Disease Among Adults With Work-Related Asthma, 2012-2017

INTRODUCTION

Asthma is associated with an increased risk for cardiovascular disease, and adults with persistent, severe asthma have a significantly higher risk of cardiovascular disease than adults with intermittent or no asthma.

METHODS

The objective of this cross-sectional study was to assess the association between work-related asthma status and cardiovascular disease among ever-employed adults (aged 18-64 years) with current asthma using data from the 2012-2017 Behavioral Risk Factor Surveillance System Asthma Call-Back Survey from 37 states and the District of Columbia. Weighted prevalence ratios and 95% CIs, adjusted for age, sex, race/ethnicity, education, household income, smoking status, chronic obstructive pulmonary disease, diabetes, and BMI, were calculated. In addition, the associations of cardiovascular disease with adverse asthma outcomes and asthma control among adults with work-related asthma were examined. Analyses were conducted in 2021.

RESULTS

Among an estimated annualized 14.8 million ever-employed adults aged 18-64 years with current asthma, adults with work-related asthma (prevalence ratio=1.5; 95% CI=1.2, 1.8) and possible work-related asthma (prevalence ratio=1.2; 95% CI=1.0, 1.5) were significantly more likely to have cardiovascular disease than adults with non-work-related asthma. Among adults with work-related asthma, those with very poorly controlled asthma (prevalence ratio=1.8; 95% CI=1.3, 2.5) and an asthma-related emergency room visit (prevalence ratio=1.5; 95% CI=1.1, 2.0) were significantly more likely to have cardiovascular disease.

CONCLUSIONS

Adults with work-related asthma were more likely to have cardiovascular disease than those with non-work-related asthma. Primary prevention, early diagnosis, and implementation of optimal work-related asthma management are essential for workers' health. Cardiovascular disease should be considered where appropriate when diagnosing and recommending treatment and interventions for adults with work-related asthma.

Work-related asthma surveillance in Washington State: time trends, industry rates, and workers' compensation costs, 2002-2016

Objective: Washington State's work-related asthma (WRA) surveillance program utilizes workers' compensation (WC) data as its primary data source and has spanned a 15-year time period. This study analyses trends for WRA claim incidence rates compared to all WC claim incidence rates. WRA claim incidence rates and WC costs are analyzed by industry. Methods: Potential WRA cases were identified through the WC system and through direct provider report and classified by industry, age, and year of illness onset. WRA claim rates by industry and year were calculated using total work hours reported by employers covered by the WC system. Claim costs for accepted claims were compared by industry and year. Results: WRA claim incidence rates decreased 8.9% (95% CI: -10.6, -7.2) annually for the time period 2002-2016. The decline in WRA claim incidence rate is slightly faster than the incidence rate for all WC claims which had its steepest decrease from 2007 to 2010 at an estimated annual 8.4% decrease (95% CI: -11.8, -5.0). WRA claim rates were highest for workers in Public Administration, Manufacturing, and the Agricultural, Forestry, Fishing and Hunting industries. Median claim costs for WRA did not change significantly by year (p = 0.2, range $595-$1442) and the distribution of WRA WC claim costs by industry were highest in Manufacturing (21.3%) and Construction (16.4%) industries. Conclusion: WRA claim incidence rates are declining in Washington State. The cause for the decline is unclear. Workers across all industries in Washington remain at risk for WRA.

Incidence of Occupational Asthma and Exposure to Toluene Diisocyanate in the United States Toluene Diisocyanate Production Industry

Objective

This study examines asthma risk in facilities producing toluene diisocyanate (TDI).

Methods

A total of 197 workers were monitored from 2007 to 2012. TDI air concentrations were used to estimate exposures.

Results

The incidence of cases consistent with TDI-induced asthma was 0.009 per person-years (seven cases) or consistent with TDI-induced asthma or asthma indeterminate regarding work-relatedness was 0.012 (nine cases). Increased risk of cases consistent with TDI asthma was observed for cumulative (odds ratio [OR] = 2.08, 95% confidence interval [CI] 1.07 to 4.05) per logarithm parts per billion-years and peak TDI exposures (OR = 1.18, 95% CI 1.06 to 1.32) (logarithm parts per billion). There was a weak association with cumulative and peak exposures for decline of short-term forced expiratory volume in one second (FEV₁). Asthma symptoms were associated with workers noticing an odor of TDI (OR 6.02; 95% CI 1.36 to 26.68).

Conclusions

There is evidence that cumulative and peak exposures are associated with TDI-induced asthma.

Isocyanates and work-related asthma: Findings from California, Massachusetts, Michigan, and New Jersey, 1993-2008

BACKGROUND

Isocyanates remain a leading cause of work-related asthma (WRA).

METHODS

Two independent data systems were analyzed for the period 1993-2008: (1) State-based WRA case surveillance data on persons with isocyanate-induced WRA from four states, and (2) Occupational Safety and Health Administration (OSHA) Integrated Management Information System (IMIS) isocyanate air sampling results.

RESULTS

We identified 368 cases of isocyanate-induced WRA from 32 industries and 678 OSHA isocyanate air samples with detectable levels from 31 industries. Seventeen industries were unique to one or the other dataset.

CONCLUSION

Isocyanate-induced WRA continues to occur in a wide variety of industries. Two data systems uncovered industries with isocyanate exposures and/or illness. Improved control measures and standards, including medical surveillance, are needed. More emphasis is needed on task-specific guidance, spill clean-up procedures, skin and respiratory protection, and targeted medical monitoring to mitigate the hazards of isocyanate use.

Primary Care of the Patient with Asthma

Obstructive lung disease includes asthma and chronic obstructive pulmonary disease (COPD). Because a previous issue of Medical Clinics of North America (2012;96[4]) was devoted to COPD, this article focuses on asthma in adults, and addresses some topics about COPD not addressed previously. Asthma is a heterogeneous disease marked by variable airflow obstruction and bronchial hyperreactivity. Onset is most common in early childhood, although many people develop asthma later in life. Adult-onset asthma presents a particular challenge in the primary care clinic because of incomplete understanding of the disorder, underreporting of symptoms, underdiagnosis, inadequate treatment, and high rate of comorbidity.

Health impacts from living near a major industrial park in Oman

Background

Oman is heading towards heavy industrialisation with rapid establishment of new industrial parks. One of these, the Sohar Industrial Zone (SIZ) started to operate in 2006 and includes many industries that potentially affect local air quality and the health status of its surrounding residents. The study aim was to assess the health effects in a population of ≥20 years old, living in the residential area around the SIZ.

Methods

Area-specific health care visits data for acute respiratory diseases (ARD), asthma, conjunctivitis and dermatitis were obtained for the period between January 1, 2006, and December 31, 2010. Exposure was defined as distance from the SIZ to determine high, intermediate, and control exposure zones (≤5, >5–10, and ≥20 km from the SIZ respectively). Generalized additive models were used to model age and gender adjusted monthly health events for the selected diseases, adjusted for age and gender-specific population smoking prevalence. The high and intermediate exposure zones were later combined in the models because of their similarity of effects. Exposure effect modification by age, gender and socio-economic status (SES) were examined.

Results

Living within the high and intermediate exposure zones was associated with a greater risk ratio for ARD (RR: 2.02; 95 % CI: 1.88–2.17), asthma (RR: 3.61; 95 % CI: 2.96–4.41), conjunctivitis (RR: 2.83; 95 % CI: 2.47–3.24), and dermatitis (RR: 2.11; 95 % CI: 1.86–2.39), compared to the control exposure zone. Greater exposure effects were observed amongst ages ≥50 years and lower SES groups.

Conclusion

This is the first study carried out in Oman to assess the link between environmental exposure and health. These findings hope to contribute to building up evidence for environmental health and sustainable development policy in the country.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1866-3) contains supplementary material, which is available to authorized users.

Work-related asthma—22 states, 2012

Work-related asthma (WRA) is a preventable occupational disease associated with serious adverse health outcomes. Using the 2006-2009 Behavioral Risk Factor Surveillance System (BRFSS) Adult Asthma Call-back Survey (ACBS) data from 38 states and the District of Columbia, CDC estimated that among ever-employed adults with current asthma, the proportion of current asthma that is work-related was 9.0%. In 2011, the BRFSS cellular telephone samples were added to the traditional landline telephone samples and the weighting methodology was changed. In 2012, a revised ACBS question on WRA diagnosis was asked. To provide updated estimates of current asthma prevalence and the proportion of asthma that is work-related, by state, CDC analyzed data from BRFSS and ACBS collected from 22 states using both landline and cellular telephone samples during 2012. This report summarizes the results of that analysis, which indicate that 9.0% of adults had current asthma and that among ever-employed adults with current asthma, the overall proportion of current asthma that is work-related was 15.7%. State-specific proportions of asthma that is work-related ranged from 9.0% to 23.1%. Distribution of the proportion of WRA significantly differed by age and was highest among persons aged 45-64 years (20.7%). These findings provide a new baseline after the implementation of changes in survey methodology and the adoption of a revised WRA question. These results can assist states, other government agencies, health professionals, employers, workers, and worker representatives to better target intervention and prevention efforts to reduce the burden of WRA.

Log-Linear Modeling of Agreement among Expert Exposure Assessors

BACKGROUND

Evaluation of expert assessment of exposure depends, in the absence of a validation measurement, upon measures of agreement among the expert raters. Agreement is typically measured using Cohen's Kappa statistic, however, there are some well-known limitations to this approach. We demonstrate an alternate method that uses log-linear models designed to model agreement. These models contain parameters that distinguish between exact agreement (diagonals of agreement matrix) and non-exact associations (off-diagonals). In addition, they can incorporate covariates to examine whether agreement differs across strata.

METHODS

We applied these models to evaluate agreement among expert ratings of exposure to sensitizers (none, likely, high) in a study of occupational asthma.

RESULTS

Traditional analyses using weighted kappa suggested potential differences in agreement by blue/white collar jobs and office/non-office jobs, but not case/control status. However, the evaluation of the covariates and their interaction terms in log-linear models found no differences in agreement with these covariates and provided evidence that the differences observed using kappa were the result of marginal differences in the distribution of ratings rather than differences in agreement. Differences in agreement were predicted across the exposure scale, with the likely moderately exposed category more difficult for the experts to differentiate from the highly exposed category than from the unexposed category.

CONCLUSIONS

The log-linear models provided valuable information about patterns of agreement and the structure of the data that were not revealed in analyses using kappa. The models' lack of dependence on marginal distributions and the ease of evaluating covariates allow reliable detection of observational bias in exposure data.

Patient-physician communication about work-related asthma: what we do and do not know

BACKGROUND

Effective patient-physician communication is the key component of the patient-physician relationship.

OBJECTIVE

To assess the proportion of ever-employed adults with current asthma who talked about asthma associated with work with their physician or other health professional and to identify factors associated with this communication.

METHODS

The 2006 to 2010 Behavioral Risk Factor Surveillance System Asthma Call-Back Survey data from 40 states and the District of Columbia for ever-employed adults (≥18 years old) with current asthma (N = 50,433) were examined. Multivariable logistic regression analyses were conducted to identify factors associated with communication with a health professional about asthma and work.

RESULTS

Among ever-employed adults with current asthma, 9.1% were ever told by a physician that their asthma was related to any job they ever had and 11.7% ever told a physician or other health professional that this was the case. When responses to the 2 questions were combined, the proportion of those who communicated with a health professional about asthma and work was 14.7%. Communication with a health professional about asthma and work was associated with age, race or ethnicity, employment, education, income, insurance, and urgent treatment for worsening asthma.

CONCLUSION

A small proportion of patients with asthma might communicate with a health professional about asthma associated with work. Future studies should examine whether patients with asthma ever discussed with a health professional the possibility that their asthma might be related to work to provide information on the frequency of patient-clinician communication about asthma related to work.

Occupation held at the time of asthma symptom development

BACKGROUND

Examining occupations other than those held when asthma symptoms first developed may not correctly identify occupations with higher risk of asthma onset.

METHODS

To determine the occupation held when individuals first developed asthma symptoms, we examined 2010 National Health Interview Survey data for working adults with current asthma.

RESULTS

Overall 37.1% of working adults with current asthma developed asthma while employed. Of these, the highest proportions of individuals identified office and administrative support (13.3%), sales and related (9.4%), and management (8.5%) as the occupation held when asthma first developed; 37.8% had a different current occupation than at asthma onset, and estimates of a change in occupation were highest for those who developed asthma while working in business and financial operations (49.3%), sales and related (48.6%), and healthcare support (43.8%) occupations.

CONCLUSION

Future population-based studies should further examine associations between asthma and occupation held at time of asthma onset.

Occupational asthma incidence: findings from the behavioral risk factor surveillance system asthma call-back survey--United States, 2006-2009

BACKGROUND

Occupational asthma (OA) is new-onset asthma or the recurrence of previously quiescent asthma caused by workplace exposures.

OBJECTIVE

To estimate the incidence of population-based new-onset OA and the proportion of incident asthma that is work-related.

METHODS

Behavioral Risk Factor Surveillance System and Asthma Call-back Survey data collected from persons aged ≥18 years during 2006-2009 in 38 states and the District of Columbia were analyzed. Incident health professional-diagnosed new-onset OA cases were persons whose asthma was diagnosed for the first time within the past 12 months whose health professional indicated their asthma was related to their work. Incident potential new-onset OA cases were persons with asthma diagnosed within the past 12 months who did not have health professional-diagnosed work-related asthma but described their asthma as caused by workplace exposures. The proportion of incident asthma that is work-related was calculated using the 2006-2008 estimate of adult asthma incidence (3800 per million).

RESULTS

The estimated annual incidence of health professional-diagnosed new-onset OA was 179 (95% CI: 113-245) per million population. For combined health professional-diagnosed and potential new-onset OA the incidence was 692 (95% CI: 532-853) per million population. The proportion of incident asthma among adults that is work-related was 4.7% for health professional-diagnosed new-onset OA and 18.2% for combined health professional-diagnosed and potential new-onset OA.

CONCLUSIONS

New-onset asthma in as many as one of six adult patients might be associated with work. Clinicians should consider the role of occupational exposures when evaluating adults with incident asthma which may uncover opportunities for early intervention and reversal of an otherwise chronic disease.

Characteristics associated with health care professional diagnosis of work-related asthma among individuals who describe their asthma as being caused or made worse by workplace exposures

OBJECTIVE

To identify factors associated with health care professional-diagnosed work-related asthma (WRA) among adults who describe their asthma as being caused or made worse by workplace exposures (possible WRA).

METHODS

We calculated prevalence ratios adjusted for age and sex using data from the 2006 to 2008 Behavioral Risk Factor Surveillance System Asthma Call-Back Survey from 37 states and the District of Columbia for ever-employed adults with current asthma and possible WRA.

RESULTS

An estimated 17.6% of ever-employed adults with current asthma and possible WRA had health care professional-diagnosed WRA. Health care professional-diagnosed WRA was associated with age, income, employment status, asthma control level, asthma attack, emergency department visit, hospitalization, urgent treatment, and changing/quitting a job due to asthma.

CONCLUSIONS

Among ever-employed adults with possible WRA, health care professional-diagnosed WRA is associated with poorer asthma control and frequent unscheduled health care visits.

Physician-patient communication regarding asthma and work

BACKGROUND

Healthy People 2020-specific respiratory diseases objectives seek to increase the proportion of people with current asthma who receive appropriate asthma care. For adults, this includes a discussion of whether asthma is work-related.

PURPOSE

To establish a baseline measure of physician-patient communication regarding asthma and work.

METHODS

This study used data from 27,157 non-institutionalized U.S. adult respondents of the 2010 National Health Interview Survey (analyzed in 2011). Adults employed at any time in the 12 months prior to the interview with a health-professional diagnosis of current asthma who have been told by a health professional that their asthma was probably work-related or ever discussed the relatedness of asthma and work were identified. Weighted proportions and, using logistic regression analysis, prevalence ORs for factors that may have predicted communication with a health professional regarding an asthma-work relationship were calculated.

RESULTS

An estimated 6.6% (95% CI=5.1%, 8.2%) of employed adults with current asthma have been told that their asthma is work-related. Among those not so informed, 7.4% (95% CI=5.6%, 9.2%) ever discussed the topic. When responses to both questions were considered, the proportion was 13.5% (95% CI=11.3%, 15.8%). Employed adults aged ≥30 years, those reporting adverse asthma outcomes, and those of Hispanic ethnicity had higher odds of having communication with a health professional about the relation between their asthma and their work.

CONCLUSIONS

One in seven employed adults with asthma report communicating with their health professional about the role of workplace exposures in their asthma. Opportunities to increase this dialogue should be examined.

Is childhood asthma associated with educational level and longest-held occupation?

Children with asthma can experience chronic morbidity that may interfere with education and career progression. The authors investigated retrospectively whether a history of childhood asthma is associated with educational level and longest-held occupation, by gender. Cross-sectional analysis included a nationally representative sample of 10,452 adults aged ≥20 years who participated in the US National Health and Nutrition Examination Survey (2001-2004). Logistic regression was used to assess associations between a childhood-asthma history and educational level, employment, and longest-held occupation. An estimated 6.9% of men and 5.8% of women had a childhood-asthma history. Persons with a childhood-asthma history tended to have a higher educational level than those with no asthma history. Among those who ever worked, and after adjustment for age and race/ethnicity, men with a childhood-asthma history were more likely to work in health-diagnosing occupations, other professional occupations, and as cooks; women with a childhood-asthma history were more likely to work in management-related, entertainment-related, and health service occupations. Compared with those with no asthma history, persons with a childhood-asthma history tended to achieve a higher educational level and, if they worked, were more likely to work in particular occupations.

Role of infection in the development and exacerbation of asthma

Respiratory infections are associated with wheezing illnesses in all ages and may also impact the development and severity of asthma. Respiratory tract infections caused by viruses, Chlamydophila or Mycoplasma have been hypothesized to have significant roles in the pathogenesis of asthma. Progress is being made toward establishing the mechanisms by which these agents can cause acute wheezing and impact the pathophysiology of asthma. Host factors probably contribute to the risk of asthma inception and exacerbation, and these contributions may also vary with respect to early- versus adult-onset disease. This review discusses these various associations as they pertain to the development and exacerbation of asthma.

Occupational asthma: what can be done to prevent it?

Occupational asthma (OA) accounts for at least 10% of cases of adult asthma and presents as intermittent asthma occurring at the workplace and remitting on weekends and holidays, or persistent asthma, especially if the diagnosis and early intervention is delayed. OA is under-recognized, challenging and time-consuming to diagnose, difficult to confirm with currently available tests and complex in terms of legal implications of disability and impairment. Over 400 agents have been identified as causing OA with allergic triggers accounting for 80-90% of cases. Managing the worker with OA is demanding as it requires the most thorough evaluation with attention to detail to provide an accurate diagnosis and develop a thoughtful treatment recommendation. This frequently has to occur in the context of various competing entities including management, unions, insurance carriers and attorneys. The primary goal is excellent employee health through interventions that may allow the worker to continue in their occupation safely. Primary, secondary and tertiary prevention measures have been adopted for various types of OA with success. Novel approaches may become available and be beneficial to identify and treat OA early before severe, chronic, unremitting and irreversible changes occur.

Surveillance of work-related asthma in new york state

OBJECTIVE

The objective of this paper is to determine the percent of adults with asthma attributable to work and describe characteristics of the work-related asthma population in New York State. Sociodemographic and control characteristics of those with and without work-related asthma are compared.

METHODS

Data from three population-based surveys and one case-based surveillance system were analyzed. Work-relatedness of asthma was determined by self-report for the population-based surveys and by physician report for the case-based system. Self-reported sociodemographic and control characteristics were analyzed for the population-based surveys by work-relatedness.

RESULTS

The percent of work-relatedness among adults with current asthma in New York State ranged from 10.6% to 44.5%. Significantly more adults with work-related asthma had poorly controlled asthma than those without work-related asthma. More adults with work-related asthma also tended to be employed in the manufacturing, educational services, and public administration industries than the general population. The most frequently reported exposure was dust.

CONCLUSIONS

Adults with work-related asthma have decreased control and adverse socioeconomic impacts compared to those with asthma that is not work-related. Increased recognition and physician reporting is necessary to further prevent the impact of work-related exposures.

Prevalence of work-related asthma in Michigan, Minnesota, and Oregon

INTRODUCTION

Adults who have asthma that is caused or aggravated by triggers at work experience a reduced quality of life. In this study, the authors sought to estimate the proportion of asthma that is associated with work using a state-based survey of adults with asthma.

METHODS

In 2005, Michigan, Minnesota, and Oregon piloted the Behavioral Risk Factor Surveillance System Adult Asthma Call-Back Survey, with sample sizes of 867, 469, and 1072, respectively. Six questions addressing work-related asthma (WRA) were analyzed to generate estimates of the proportion of adult asthma that is work-related and compare those with and without WRA.

RESULTS

Over half of all adults with asthma (53%) reported that their asthma was caused or made worse by any job they ever had, and among these respondents reporting WRA, only 21.5% to 25.1% reported ever telling or being told by a health professional that their asthma was work-related. Additionally, adults with WRA consistently reported poorer asthma control and higher health care utilization than adults with non-WRA.

CONCLUSIONS

WRA is a common but frequently unrecognized health problem, and this lack of recognition might contribute to poorer asthma control among adults with WRA. Because early recognition, treatment, and management of WRA are crucial for improving long-term prognosis, clinicians need to include assessment of workplace triggers in both their diagnostic and treatment plans for adult patients with asthma.

Review: use of electronic medical records for health outcomes research: a literature review

This review assessed the use of electronic medical record (EMR) systems in outcomes research. We systematically searched PubMed to identify articles published from January 2000 to January 2007 involving EMR use for outpatient-based outcomes research in the United States. EMR-based outcomes research studies (n = 126) have increased sixfold since 2000. Although chronic conditions were most common, EMRs were also used to study less common diseases, highlighting the EMRs' flexibility to examine large cohorts as well as identify patients with rare diseases. Traditional multi-variate modeling techniques were the most commonly used technique to address confounding and potential selection bias. Data validation was a component in a quarter of studies, and many evaluated the EMR's ability to achieve similar results previously achieved using other data sources. Investigators using EMR data should aim for consistent terminology, focus on adequately describing their methods, and consider appropriate statistical methods to control for confounding and treatment-selection bias.

Asthma caused by occupational exposures is common - a systematic analysis of estimates of the population-attributable fraction

Background

The aim of this paper is to highlight emerging data on occupational attributable risk in asthma. Despite well documented outbreaks of disease and the recognition of numerous specific causal agents, occupational exposures previously had been relegated a fairly minor role relative to other causes of adult onset asthma. In recent years there has been a growing recognition of the potential importance of asthma induced by work-related exposures

Methods

We searched Pub Med from June 1999 through December 2007. We identified six longitudinal general population-based studies; three case-control studies and eight cross-sectional analyses from seven general population-based samples. For an integrated analysis we added ten estimates prior to 1999 included in a previous review.

Results

The longitudinal studies indicate that 16.3% of all adult-onset asthma is caused by occupational exposures. In an overall synthesis of all included studies the overall median PAR value was 17.6%.

Conclusion

Clinicians should consider the occupational history when evaluating patients in working age who have asthma. At a societal level, these findings underscore the need for further preventive action to reduce the occupational exposures to asthma-causing agents.

An overview of 9/11 experiences and respiratory and mental health conditions among World Trade Center Health Registry enrollees

To date, health effects of exposure to the September 11, 2001 disaster in New York City have been studied in specific groups, but no studies have estimated its impact across the different exposed populations. This report provides an overview of the World Trade Center Health Registry (WTCHR) enrollees, their exposures, and their respiratory and mental health outcomes 2-3 years post-9/11. Results are extrapolated to the estimated universe of people eligible to enroll in the WTCHR to determine magnitude of impact. Building occupants, persons on the street or in transit in lower Manhattan on 9/11, local residents, rescue and recovery workers/volunteers, and area school children and staff were interviewed and enrolled in the WTCHR between September 2003 and November 2004. A total of 71,437 people enrolled in the WTCHR, for 17.4% coverage of the estimated eligible exposed population (nearly 410,000); 30% were recruited from lists, and 70% were self-identified. Many reported being in the dust cloud from the collapsing WTC Towers (51%), witnessing traumatic events (70%), or sustaining an injury (13%). After 9/11, 67% of adult enrollees reported new or worsening respiratory symptoms, 3% reported newly diagnosed asthma, 16% screened positive for probable posttraumatic stress disorder (PTSD), and 8% for serious psychological distress (SPD). Newly diagnosed asthma was most common among rescue and recovery workers who worked on the debris pile (4.1%). PTSD was higher among those who reported Hispanic ethnicity (30%), household income < $25,000 (31%), or being injured (35%). Using previously published estimates of the total number of exposed people per WTCHR eligibility criteria, we estimate between 3,800 and 12,600 adults experienced newly diagnosed asthma and 34,600-70,200 adults experienced PTSD following the attacks, suggesting extensive adverse health impacts beyond the immediate deaths and injuries from the acute event.

A new method of assessing aerosolized bacteria generated during orthodontic debonding procedures

INTRODUCTION

The main objective of this study was to assess the efficacy of a new and innovative method of harvesting bacteria that are aerosolized during orthodontic debonding. Additionally, the protection efficacy of several commercially available masks from such aerosols was assessed in a pilot study.

METHODS

Twenty-six subjects were debonded during aerosol sampling, by using an innovative collection system to harvest bonding dust liberated during debonding. Dark-field microscopy, gram-stain microscopy, and chemical identification were used to determine speciation of the collected aerosol from 23 subjects. Three additional subjects were used to test 3 commercial dental or protective masks to determine whether they provide effective protection from the aerosol.

RESULTS

Twenty-one species of oral bacteria were identified by the new sampling technique. Two of the 3 masks that were tested offered no protection against the aerosolized bacteria.

CONCLUSIONS

A new and effective method for collecting airborne bacteria is presented. Some conventional dental masks offer no protection from aerosolized organisms liberated during debonding procedures. Further assessment of mask efficacy is ongoing.

Asthma incidence: data from the National Health Interview Survey, 1980-1996

OBJECTIVE

To obtain historical estimates of US asthma incidence from 17 years of health survey data.

METHODS

The 1980 through 1996 National Health Interview Survey contained a question asking about the time of asthma onset in persons with asthma. Annual past year incidence estimates were calculated from self-reports of asthma status.

RESULTS

Incidence increased from 2.5 per 1,000 (SE 0.37) in 1980 to 6.0 per 1,000 (SE 0.75) in 1996. Incidence increased faster in children than in adults and increased in females but not in males during this time.

CONCLUSION

These findings suggest that increasing asthma incidence contributed to the increasing prevalence during this time.

New insights into occupational asthma

PURPOSE OF REVIEW

To examine recent publications on the types of agents involved in occupational asthma, the mechanisms by which they induce asthma, and how best to evaluate and treat workers suspected of this respiratory condition.

RECENT FINDINGS

High rates of occupational asthma and inhalation accidents were found in workers in crafts and related occupations in the manufacturing industries, and in plant and machine operatives; cleaners and construction workers may also be at risk. Further data support a role for CD4 T cells in low-molecular-weight agent-induced asthma, such as with isocyanates, and neurogenic mechanisms may also be involved. The use of noninvasive measures of airway inflammation in the diagnosis and management of occupational asthma such as sputum eosinophils monitoring is promising, although this is less obvious for exhaled nitric oxide. Finally, the persistence of troublesome asthma even after withdrawal from relevant exposure has been re-emphasized and surveillance programs have been proposed.

SUMMARY

Further data have been gathered on the prevalence of occupational asthma in various working populations, its mechanisms of development, the contribution of noninvasive measures of airway inflammation in the diagnosis and management of this condition, and its management and prevention.

Overweight, obesity, and incident asthma: a meta-analysis of prospective epidemiologic studies

RATIONALE

Although obesity has been implicated as an asthma risk factor, there is heterogeneity in the published literature regarding its role in asthma incidence, particularly in men.

OBJECTIVES

To quantify the relationship between categories of body mass index (BMI) and incident asthma in adults and to evaluate the impact of sex on this relationship.

METHODS

Online bibliographic databases were searched for prospective studies evaluating BMI and incident asthma in adults. Independent observers extracted data regarding annualized asthma incidence from studies meeting predetermined criteria, within defined categories of normal weight (BMI < 25), overweight (BMI, 25-29.9), and obesity (BMI >or= 30). Data were analyzed by inverse-variance-weighted, random-effects meta-analysis. Stratified analysis between BMI categories and within sex was performed.

RESULTS

Seven studies (n=333,102 subjects) met inclusion criteria. Compared with normal weight, overweight and obesity (BMI >or= 25) conferred increased odds of incident asthma, with an odds ratio (OR) of 1.51 (95% confidence interval [CI], 1.27-1.80). A dose-response effect of elevated BMI on asthma incidence was observed; the OR for incident asthma for normal-weight versus overweight subjects was 1.38 (95% CI, 1.17-1.62) and was further elevated for normal weight versus obesity (OR, 1.92; 95% CI, 1.43-2.59; p<0.0001 for the trend). A similar increase in the OR of incident asthma due to overweight and obesity was observed in men (OR, 1.46; 95% CI, 1.05-2.02) and women (OR, 1.68; 95% CI, 1.45-1.94; p=0.232 for the comparison).

CONCLUSIONS

Overweight and obesity are associated with a dose-dependent increase in the odds of incident asthma in men and women, suggesting asthma incidence could be reduced by interventions targeting overweight and obesity.

Quality of occupational history assessments in working age adults with newly diagnosed asthma

BACKGROUND

Approximately 10 to 15% of new-onset asthma in adults is attributable to occupational exposure. The occupational history is the most important instrument in the diagnosis of occupational asthma (OA).

STUDY OBJECTIVES

To assess the quality of occupational histories obtained by health-care providers and to measure the prevalence of clinician-diagnosed OA in a population at elevated risk for OA.

SETTING

An academic US Department of Veteran Affairs medical center.

STUDY POPULATION

One hundred ninety-seven adults (age range, 18 to 55 years) with newly diagnosed asthma who had completed pulmonary function testing (PFT) and a structured respiratory health questionnaire.

MEASUREMENTS

We conducted a structured retrospective comparison of occupational respiratory health history documented by clinicians with data documented by patients on a structured questionnaire. We analyzed PFT results to assess physiologic impairment. We also conducted a structured examination of the actions taken by health-care providers based on their occupational history assessments.

RESULTS

Patient self-reports of respiratory exposures and symptoms were common. A job title was documented by one or more clinicians in 75% of patient medical records. Additional occupational history data were charted much less frequently. A diagnosis of OA was made in only 2% of patients. Clinical action to address OA was documented for only one patient.

CONCLUSIONS

Clinicians who manage adults with newly diagnosed asthma take incomplete occupational histories. We detected discordance between the occupational exposure histories documented by patients and those charted by clinicians. OA may go unrecognized and possibly undermanaged by clinicians.

Partial questionnaire designs, questionnaire non-response, and attributable fraction: applications to adult onset asthma

The attributable fraction (AF) is often used to explore the policy implications of an association between a disease and an exposure. To date, there have been no proposed estimators of AF in the context of partial questionnaire designs (PQD). The PQD, first proposed in a public health context by Wacholder is often used to enhance response rates in questionnaires. It involves eliciting responses from each subject on preassigned subsets of questions, thereby reducing the burden of response. We propose a computationally efficient method of estimating logistic (or more generally, binary) regression parameters from a PQD model where there is non-response to the questionnaire and the rates of non-response differ between sub-populations. Assuming a log-linear model for the distribution of missing covariates, we employ the methods of Wacholder to motivate consistent estimating equations, and weight each subject's contribution to the estimating function by the inverse probability of responding to the questionnaire. We also propose techniques for goodness-of-fit to assist in model selection. We then use the PQD regression estimates to derive an estimate of AF similar to that proposed by Bruzzi. Finally, we demonstrate our methods using data obtained from a study on adult occupational asthma, conducted within a Massachusetts HMO. Although we concentrate on a particular type of missing data mechanism, other missing data techniques can be incorporated into AF estimation in a similar manner.

The proportion of self-reported asthma associated with work in three States: California, Massachusetts, and Michigan, 2001

OBJECTIVES

To assess the proportion of adult asthma at the state level that may be related to work.

DESIGN

Work-related asthma questions were added to the 2001 Behavioral Risk Factor Surveillance System (BRFSS) questionnaire in California, Massachusetts, and Michigan.

RESULTS

Findings indicate 7.4-9.7% of those with current asthma reported that their asthma may be work related. These results estimate that approximately 137,000 adults in California, 39,000 in Massachusetts, and 63,000 in Michigan have asthma that may be work related.

CONCLUSIONS

These findings are unique in providing population-based estimates at the state level that illustrate that a substantial portion of adult asthma morbidity is due to exposures in the work environment.

Case-by-case assessment of adult-onset asthma attributable to occupational exposures among members of a health maintenance organization

OBJECTIVE

In a general population of employed persons with health insurance, what proportion of adult-onset asthma is caused by occupational exposures?

METHOD

We conducted a 2-year prospective study to identify adult-onset asthma among health maintenance organization (HMO) members. Telephone interviews regarding occupational exposures, symptoms, medication use, and triggers were used to assess likelihood of work-related asthma for each case. Weighted estimating equations were used to adjust the proportion of asthma attributable to workplace exposures for factors associated with interview participation.

RESULTS

Overall, 29% (95% confidence interval, 25-34%) of adult-onset asthma was attributable to workplace exposures; 26% (21-30%) and 22% (18-27%) of cases had asthma attributable to occupational irritant and sensitizer exposures, respectively.

CONCLUSIONS

Occupational exposures, including irritants, are important causes of adult-onset asthma.

The frequency of workplace exacerbation among health maintenance organisation members with asthma

OBJECTIVES

Workplace conditions can potentially contribute to the worsening of asthma, yet it is unclear what percentage of adults with asthma experience workplace exacerbation of symptoms. The objective of this investigation was to determine the prevalence of workplace exacerbation of asthma (WEA).

METHODS

Adults with asthma aged 18-44 were enrolled into the baseline survey of a longitudinal study. Members of a health maintenance organisation were considered candidates for participation if they fulfilled membership, diagnostic, and treatment criteria based on automated review of electronic billing, claims, and pharmacy records. Diagnosis and treatment were confirmed by manual review of medical records. A telephone questionnaire was administered. A work related symptom score was assigned to each participant based on responses to questions about work related asthma symptoms, medication use, and symptom triggers. Blinded to participants' answers to these questions, two researchers independently reviewed the self-reported work histories and assigned exposure ratings. A final exposure score was then calculated. Participants with sufficient evidence for work related symptoms and exposure were classified as having WEA.

RESULTS

Of the 598 participants with complete data, 557 (93%) were working, and 136 (23%) fulfilled the criteria for WEA. Those with WEA were more likely to be male and to report that they had been bothered by asthma symptoms during the past seven days.

CONCLUSIONS

Workplace exacerbation of asthma was common in this study population, occurring in over a fifth of these adults with asthma. Physicians should consider that work can contribute to the exacerbation of symptoms when treating adults with asthma.

Characteristics of work related asthma: results from a population based survey

OBJECTIVES

Many risk factors for asthma have been investigated, one of which is the workplace. Work related asthma is a frequently reported occupational respiratory disease yet the characteristics which distinguish it from non-work related asthma are not well understood. The purpose of this study was to examine differences between work related and non-work related asthma with respect to healthcare use and asthma control characteristics.

METHODS

Data from the Massachusetts Behavioral Risk Factor Surveillance System for 2001 and 2002 were used for this analysis. Work related status of asthma was determined by self-report of ever having been told by a physician that asthma was work related. Healthcare measures evaluated were emergency room visits and physician visits for worsening asthma and for routine care. Characteristics of asthma control evaluated were frequency of asthma symptoms, asthma attacks, difficulty sleeping, and asthma medication usage in the last 30 days and limited activity in the past 12 months.

RESULTS

The prevalence of lifetime and current asthma in Massachusetts were 13.0% and 9.2%, respectively. Approximately 6.0% (95% CI 4.8 to 7.3) of lifetime and 6.2% (95% CI 4.7 to 7.8) of current asthma cases were work related. In the past 12 months, individuals with work related current asthma were 4.8 times (95% CI 2.0 to 11.6) as likely to report having an asthma attack, 4.8 times (95% CI 1.8 to 13.1) as likely to visit the emergency room at least once, and 2.5 times (95% CI 1.1 to 6.0) as likely to visit the doctor at least once for worsening asthma compared to individuals with non-work related asthma.

CONCLUSIONS

Work related asthma is associated with increased frequency of asthma attacks and use of healthcare services. A better understanding of factors that contribute to differences in healthcare use and asthma control is needed to improve prevention and control strategies for individuals suffering from the disease.

Respiratory morbidity in office workers in a water-damaged building

We conducted a study on building-related respiratory disease and associated social impact in an office building with water incursions in the northeastern United States. An initial questionnaire had 67% participation (888/1,327). Compared with the U.S. adult population, prevalence ratios were 2.2-2.5 for wheezing, lifetime asthma, and current asthma, 3.3 for adult-onset asthma, and 3.4 for symptoms improving away from work (p < 0.05). Two-thirds (66/103) of the adult-onset asthma arose after occupancy, with an incidence rate of 1.9/1,000 person-years before building occupancy and 14.5/1,000 person-years after building occupancy. We conducted a second survey on 140 respiratory cases, 63 subjects with fewer symptoms, and 44 comparison subjects. Health-related quality of life decreased with increasing severity of respiratory symptoms and in those with work-related symptoms. Symptom status was not associated with job satisfaction or how often jobs required hard work. Respiratory health problems accounted for one-third of sick leave, and respiratory cases with work-related symptoms had more respiratory sick days than those without work-related symptoms (9.4 vs. 2.4 days/year; p < 0.01). Abnormal lung function and/or breathing medication use was found in 67% of respiratory cases, in 38% of participants with fewer symptoms, and in 11% of the comparison group (p < 0.01), with similar results in never-smokers. Postoccupancy-onset asthma was associated with less atopy than preoccupancy-onset asthma. Occupancy of the water-damaged building was associated with onset and exacerbation of respiratory conditions, confirmed by objective medical tests. The morbidity and lost work time burdened both employees and employers.