Socioeconomic outcomes in work-exacerbated asthma

Impact of Identification of Clinical Phenotypes in Occupational Asthma

Phenotypic differences and similarities in the spectrum of occupational asthma (OA) subtypes reflect the underlying mechanisms of the diverse forms of the disease, and these phenotypes provide information as to diagnostic steps and approaches to management. In large part, the phenotype reflects the existence of immunologic mechanisms and the presence or absence of a specific IgE-antibody response to a work sensitizer. However, further differences occur between OA from high- and low-molecular-weight sensitizers (chemical sensitizers), which potentially might be relevant for nonoccupational asthma. Chemical sensitizers cause a specific response that is more likely to be a late asthmatic response and specific IgE can be identified only in a minority. Irritant-induced asthma is most easily recognized when it occurs with 1 or more high-level respiratory irritant exposure(s) but is also possible with chronic low-level exposures as in cleaners, farmers, and woodworkers, as suggested from epidemiologic studies. OA chronic obstructive pulmonary disease overlap is more common in older patients and with OA from low-molecular-weight sensitizers. Removal from exposure to the causative agent is currently advised for those with OA from sensitization: further studies with omalizumab and other biologic agents are needed to determine whether these might allow return to the same exposure.

Development of an Asthma-Specific Job Exposure Matrix for Use in the United States

INTRODUCTION

Existing asthma-specific job-exposure matrices (JEMs) do not necessarily reflect current working conditions in the USA and do not directly function with occupational coding systems commonly used in the USA. We initiated a project to modify an existing JEM to address these limitations, and to apply the new JEM to the entire US employed population to estimate quantitatively the extent of probable work-related asthma exposures nationwide.

METHODS

We started with an asthma-specific JEM that was developed for northern Europe (the N-JEM) and modified it to function with the 2010 US Standard Occupational Classification (SOC-2010) codes and to reflect working conditions in the USA during the post-2000 period. This involved cross walking from the 1988 International Standard Classification of Occupations (ISCO-88) codes used in the N-JEM to the SOC-2010 codes, transferring the N-JEM exposure assignments to the SOC-2010 codes, and modifying those assignments to reflect working conditions in the USA. The new US asthma JEM (USA-JEM) assigns exposures to 19 agents organized into five categories. The USA-JEM and N-JEM were applied to the same sample of working adults with asthma to compare how they performed, and the USA-JEM was also applied to the entire 2015 US working population to estimate the extent of occupational asthma exposures nationally.

RESULTS

The USA-JEM assigns at least one asthma-related probable exposure to 47.5% and at least one possible exposure to 14.9% of the 840 SOC-2010 detailed occupations, and 9.0% of the occupations have both probable exposure to at least one agent and possible exposure to at least one other agent. The USA-JEM has greater sensitivity for cleaning products, highly reactive disinfectants and sterilants, and irritant peak exposures than the N-JEM. When applied to the entire 2015 US working population, the USA-JEM determined that 42.6% of workers had probable exposure to at least one type of occupational asthma agent.

DISCUSSION

A new asthma-specific JEM for application in the USA was developed. Additional work is needed to compare its performance to similar JEMs and, if possible, to exposure assessments generated on a case-by-case basis.

Update on the Management of Occupational Asthma and Work-Exacerbated Asthma

Work-related asthma is the most common occupational lung disease encountered in clinical practice. In adult asthmatics, work-relatedness can account for 15%-33% of cases, but delays in diagnosis remain common and lead to worse outcomes. Accurate diagnosis of asthma is the first step to managing occupational asthma, which can be sensitizer-induced or irritant-induced asthma. While latency has traditionally been recognized as a hallmark of sensitizer-induced asthma and rapid-onset a defining feature of irritant-induced asthma (as in Reactive Airway Dysfunction Syndrome), there is epidemiological evidence for irritant-induced asthma with latency from chronic moderate exposure. Diagnostic testing while the patient is still in the workplace significantly improves sensitivity. While specific inhalational challenges remain the gold-standard for the diagnosis of occupational asthma, they are not available outside of specialized centers. Commonly available tests including bronchoprovocation challenges and peak flow monitoring are important tools for practicing clinicians. Management of sensitizer-induced occupational asthma is notable for the central importance of removal from the causative agent: ideally, removal of the culprit agent; but if not feasible, this may require changes in the work process or ultimately, removal of the worker from the workplace. While workers' compensation programs may reduce income loss, these are not universal and there can be significant socio-economic impact from work-related asthma. Primary prevention remains the preferred method of reducing the burden of occupational asthma, which may include modification to work processes, better worker education and substitution of sensitizing agents from the workplace with safer compounds.

Employment status changes of workers after referral to an occupational disease clinic

Objective:

Occupational diseases (OD) are among the most significant issues of work life, with economic, medical, social, and ethical aspects. The majority of studies concerning OD focus on the causes or medical outcomes of OD. There are a limited number of studies investigating the social and economic impacts of being diagnosed with an OD. One of the important social aspects of OD is the employability of workers after an OD diagnosis. The aim of this study is to evaluate the changes in employment status after the OD diagnosis process.

Methods:

This is a cross sectional study. There were 204 eligible cases, and 198 (97%) completed the study. The study data were obtained from patient files, including OD Committee reports and questionnaires applied via telephone interview.

Results:

Among the 198 applicants, 170 (85.9%) were male and 146 (73.7%) were diagnosed with an OD. Of these workers, 106 (53.5%) had quit their current jobs. Of those workers, 89 out of 106 were in the OD group, and 17 were in the non-OD group. Diagnosis with OD (OR: 3.1 CI: 1.4-6.8) and non-union membership (OR: 11.1 CI: 5.2-23.5) increased the likelihood of quitting the job after an OD diagnosis.

Conclusion:

The short-term prognosis of OD was relatively poor. OD diagnosis or even referral to an outpatient clinic may cause quitting the job. Policies should account for the risk of unemployment after an OD diagnosis, and OD surveillance systems should obtain data on the employment status of workers following diagnosis.

Current and new challenges in occupational lung diseases

Occupational lung diseases are an important public health issue and are avoidable through preventive interventions in the workplace. Up-to-date knowledge about changes in exposure to occupational hazards as a result of technological and industrial developments is essential to the design and implementation of efficient and effective workplace preventive measures. New occupational agents with unknown respiratory health effects are constantly introduced to the market and require periodic health surveillance among exposed workers to detect early signs of adverse respiratory effects. In addition, the ageing workforce, many of whom have pre-existing respiratory conditions, poses new challenges in terms of the diagnosis and management of occupational lung diseases. Primary preventive interventions aimed to reduce exposure levels in the workplace remain pivotal for elimination of the occupational lung disease burden. To achieve this goal there is still a clear need for setting standard occupational exposure limits based on transparent evidence-based methodology, in particular for carcinogens and sensitising agents that expose large working populations to risk. The present overview, focused on the occupational lung disease burden in Europe, proposes directions for all parties involved in the prevention of occupational lung disease, from researchers and occupational and respiratory health professionals to workers and employers.

Occupational exposures associated with severe exacerbation of asthma

BACKGROUND

The exacerbation of asthma by workplace conditions is common, but little is known about which agents pose a risk.

OBJECTIVE

We used data from an existing survey of adults with asthma to identify occupational exposures associated with severe exacerbation of asthma.

DESIGN

Questionnaires were completed by 557 working adults with asthma. Severe exacerbation of asthma in the past 12 months was defined as asthma-related hospitalization, or reports of both unplanned asthma care and treatment with a short course of oral corticosteroids. Occupational exposures for the same time period were assessed using an asthma-specific job exposure matrix. We modeled severe exacerbation to yield prevalence ratios (PRs) for exposures while controlling for potential confounders.

RESULTS

A total of 164 participants (29%) were positive for severe exacerbation, and 227 (40.8%) were assessed as being exposed to asthma agents at work. Elevated PRs were observed for several specific agents, notably the irritant subcategories of environmental tobacco smoke (PR 1.84, 95%CI 1.34-2.51) among all participants, inorganic dusts (PR 2.53, 95%CI 1.37-4.67) among men, and the low molecular weight subcategory of other highly reactive agents (PR 1.97, 95%CI 1.08-3.60) among women.

CONCLUSION

Among working adults with asthma, severe exacerbation was associated with several occupational agents.

Work-related asthma and employment status--38 states and District of Columbia, 2006-2009

OBJECTIVES

To examine differences in current employment status between persons with health professional-diagnosed work-related asthma and non-work-related asthma and to examine factors associated with unemployment in these groups.

METHODS

We analyzed the 2006-2009 Behavioral Risk Factor Surveillance System Asthma Call-back Survey for ever-employed adults (excluding those who were retired, homemakers and students at the time of the interview) with current asthma in 38 states and District of Columbia (N = 25,680). We calculated prevalence ratios (PRs) adjusted for age, sex, race/ethnicity, education and income.

RESULTS

Among adults with current asthma, individuals with work-related asthma were less likely to be currently employed for wages (PR = 0.89; 95% confidence interval [CI] = 0.84-0.95) and more likely to be unable to work (PR = 1.44; 95% CI = 1.24-1.67) than those with non-work-related asthma. Among adults with current asthma who were unemployed at the time of the interview, adults with work-related asthma did not differ from those with non-work-related asthma in naming disability as reason for unemployment (PR = 1.09; 95% CI = 0.94-1.26). However, those with work-related asthma were more likely to be unable to work for health reasons other than disability (PR = 1.46; 95% CI = 1.01-2.12) than adults with non-work-related asthma.

CONCLUSIONS

Additional studies are needed to determine what health reasons prevent individuals with work-related asthma from working and if the health reasons are asthma-related.

Exacerbation of symptoms in agricultural pesticide applicators with asthma

PURPOSE

Exacerbation is a critical event in asthma management. We investigated whether exacerbation of symptoms is associated with farming exposures among agricultural pesticide applicators with asthma.

METHODS

Participants were pesticide applicators with active asthma (wheezing and breathing problems in past 12 months) who completed enrollment questionnaires for the Agricultural Health Study (AHS). Exacerbation of asthma was defined as having visited a hospital emergency room or doctor for an episode of wheezing or whistling in the past 12 months. Exposures of interest were using 36 specific pesticides in the past 12 months and conducting various agricultural activities. Adjusted odds ratios (ORs) were estimated by logistic regression while controlling for potential confounders.

RESULTS

The 926 AHS adult pesticide applicators with active asthma included 202 (22%) with exacerbation. Inverse associations with exacerbation were observed for two herbicides [glyphosate, odds ratio (OR) = 0.5, 95% confidence interval (CI) 0.3, 0.8, and paraquat, OR = 0.3, 95% CI 0.1, 0.9] and several agricultural activities (repairing engines, grinding metal, driving diesel tractors, and performing veterinary procedures). Only asthma cases with allergies (i.e., doctor-diagnosed hay fever or eczema, 46%) had positive exacerbation-pesticide associations, with OR = 2.1 (95% CI 1.1, 4.1) for the herbicide pendimethalin and OR = 10.2 (95% CI 1.9, 55) for the insecticide aldicarb.

CONCLUSIONS

The inverse associations with two pesticides and specific farm activities are consistent with the possibility that asthma cases prone to exacerbation may avoid exposures that trigger symptoms. Although limited by small sample size and a cross-sectional design, our study suggests that use of specific pesticides may contribute to exacerbation of asthma among individuals with allergies.

RADS and its variants: asthma by another name

This article describes the different clinical variants of irritant-induced asthma, specifically focusing on high-dose irritant-induced asthma and irritant-induced work-exacerbated asthma, as well as reviews known causes, addresses the often adverse medical and socioeconomic outcomes of this complex condition, and considers issues of causation from an occupational and environmental medicine perspective.

Definitions and classification of work-related asthma

The workplace can trigger or induce asthma and cause the onset of different types of work-related asthma (WRA). Based on current knowledge of clinical features, pathophysiologic mechanisms, and evidence supporting a causal relationship, the following conditions should be distinguished in the spectrum of WRA: (1) immunologic occupational asthma (OA), (2) nonimmunologic OA, (3) work-exacerbated asthma, and (4) variant syndromes, including eosinophilic bronchitis, potroom asthma, and asthmalike disorders caused by organic dusts. The rationale, issues, and controversies relating to this approach are critically reviewed to stimulate the development of a consensus on operational definitions of the various phenotypes of WRA.

Work-related asthma: a case-based approach to management

The management of work-related asthma has some differences from management of other asthma. Components of management include not only making as accurate a diagnosis as possible, identifying the causative agent or triggers at work, and managing the asthma with pharmacologic treatment as for other patients with asthma, but also advising on the appropriate work changes that may be needed, assisting the worker with appropriate compensation claims, and supporting protective measures for coworkers. This article discusses the approaches that may be taken for patients with different forms of work-related asthma.

Work-related asthma, financial barriers to asthma care, and adverse asthma outcomes: asthma call-back survey, 37 states and District of Columbia, 2006 to 2008

BACKGROUND

Proper asthma management and control depend on patients having affordable access to healthcare yet financial barriers to asthma care are common.

OBJECTIVE

To examine associations of work-related asthma (WRA) with financial barriers to asthma care and adverse asthma outcomes.

RESEARCH DESIGN

Cross-sectional, random-digit-dial survey conducted in 37 states and District of Columbia.

SUBJECTS

A total of 27,927 ever-employed adults aged ≥18 years with current asthma.

MEASURES

Prevalence ratios (PR) for the associations of WRA with financial barriers to asthma care and of WRA with adverse asthma outcomes stratified by financial barriers.

RESULTS

Persons with WRA were significantly more likely than those with non-WRA to have at least 1 financial barrier to asthma care [PR, 1.66; 95% confidence interval (CI), 1.43-1.92]. Individuals with WRA were more likely to experience adverse asthma outcomes such as asthma attack (PR, 1.31; 95% CI, 1.22-1.40), urgent treatment for worsening asthma (PR, 1.57; 95% CI, 1.39-1.78), asthma-related emergency room visit (PR, 1.69; 95% CI, 1.41-2.03), and very poorly controlled asthma (PR, 1.54; 95% CI: 1.36-1.75). After stratifying for financial barriers to asthma care, the associations did not change.

CONCLUSIONS

Financial barriers to asthma care should be considered in asthma management, and individuals with WRA are more likely to experience financial barriers. However, individuals with WRA are more likely to experience adverse asthma outcomes than individuals with non-WRA, regardless of financial barriers. Additional studies are needed to identify medical, behavioral, occupational, or environmental factors associated with adverse asthma outcomes among individuals with WRA.

Recent advances in the management of occupational asthma

Occupational asthma (OA) is the most common occupational lung disease in industrialized countries. This respiratory disorder remains poorly diagnosed and managed, and inadequately compensated for worldwide. The most appropriate treatment for OA remains early removal from exposure to ensure that the worker has no further exposure to the causal agent with preservation of income. However, various studies demonstrate that many workers with OA continue to remain exposed to the causative agent or suffer prolonged work disruption and discrimination, and may face unemployment. Despite removal from exposure, OA frequently turns into a chronic condition and requires intensive medical management, including appropriate pharmacotherapy and patient education and counseling. There are very few studies on allergen immunotherapy in OA. Subcutaneous immunotherapy with latex extract in healthcare workers and with wheat-flour extract in subjects with baker's asthma, at adequate doses, appears to be a useful treatment in reducing cutaneous and respiratory symptoms, but should be considered as a high-risk treatment due to the appearance of systemic reactions.

New-onset adult asthma in relation to damp and moldy workplaces

OBJECTIVE

Damp and moldy indoor environments aggravate pre-existing asthma. Recent meta-analyses suggest that exposure to such environments may also induce new-onset asthma. We assessed the probability of molds being the cause of asthma in a patient series examined because of respiratory symptoms in relation to workplace dampness and molds.

METHODS

Altogether 694 such patients had been clinically assessed between 1995 and 2004. According to their histories, they had all been exposed to molds at work and had suffered from work-related lower respiratory symptoms. The investigations had included specific inhalation challenge (SIC) tests with mold extracts and serial peak expiratory flow (PEF) recordings. Using internationally recommended diagnostic criteria for occupational asthma (OA), we categorized the patients into three groups: probable, possible, and unlikely OA (156, 45, and 475 patients, respectively). The clinical details of 258 patients were analyzed, and their levels of microbial exposure were evaluated.

RESULTS

The agreement between the serial PEF recordings and SIC tests (both being either positive or negative) was 56%. In the group of probable OA, mold sensitization was found in 20%. The level of exposure and sensitization to molds was associated with probable OA. At 6 months, the follow-up examinations of 136 patients with probable OA showed that the symptoms were persistent, and no improvement in spirometry was noted despite adequate treatment. Only 58% of the patients had returned to work.

CONCLUSIONS

Exposure to damp and moldy workplaces can induce new-onset adult asthma. IgE mediation is a rare mechanism, whereas other mechanisms are unknown.

More than meets the eye: social, economic, and emotional impacts of work-related injury and illness

The impact of an occupational illness or injury on an injured worker can be severe. This study assessed several dimensions of the impact on a group of 50 injured workers, all patients at an Occupational Health Center. The dimensions assessed included aspects of access to health care, support from treating physicians in obtaining Workers' Compensation benefits, financial impacts, the role of attorneys and "Independent Medical Examiners," and the impact on mental health. Many reported that their treating physician did not want to become involved in Workers' Compensation, despite indicating a belief that the health condition was work-related. The financial impacts of a work-related diagnosis were particularly striking, with respondents reporting that they were burdened both with costs directly related to the medical care of their condition, and with coping with ongoing general expenses on a reduced income. Many respondents reported depleting savings, borrowing money, taking out retirement funds, and declaring bankruptcy in efforts to cope. Emotionally, respondents almost universally reported their diagnosis and related issues were associated with depression, anxiety, and loss of identity and self-worth. This study demonstrates how a work-related injury or illness can extend far beyond the physical impact for injured workers. Existing systems fail to adequately compensate or rehabilitate injured workers, leaving them to their own devices to deal with their losses, medical or otherwise.