New developments in 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.

Non-invasive assessment of airway inflammation in ship-engine workers

Smoking is harmful for respiratory function. In young to middle-aged men the damage is insidious and difficult to demonstrate. The respiratory impairment could increase under specific stressful conditions in the professional environment. On the hypothesis that exhaled markers are useful for assessing airway susceptibility to inhaled irritants, we measured exhaled markers and lung function in smoking and non-smoking engine-driver military coastguards before and after a patrol at sea. Eighteen men, mean age 39 yrs (range 23-58 yrs), 8 smokers, underwent spirometry, exhaled and nasal nitric oxide (eNO, nNO), exhaled carbon monoxide (CO) and exhaled breath condensate (EBC) for measures of hydrogen peroxide (H2O2), leukotriene B4 (LTB4), proteins (Prots), 8-isoprostanes (8-IsoPs), nitrite (NO2-) and nitrosothiols (RS-NOs) at baseline and after an 8-hour patrol navigation on board small, high-speed diesel-powered ships. At baseline, the smokers showed higher middle flows and CO levels, lower eNO and nNO than non-smokers, but similar levels of EBC markers; geometric means (95% confidence interval), CO: 23.6 (14.5 to 38.3) vs. 3.5 (2.5 to 5.3) ppm; eNO: 7.9 (4.8 to 12.9) vs. 26.7 (15.7 to 45.5) ppb, p=0.000. After navigation, Prots, 8-IsoPs and RS-NOs (but not lung function variables or other markers) significantly increased only in smokers; baseline vs post-navigation RS-NOs: 0.27 (0.11 to 0.65) vs. 1.30 (0.58 to 2.89) micromol, p=0.012. The respiratory consequences of a stressing environment in engine-driver military coastguards who actively smoke are better assessed by measuring EBC markers than by eNO, nNO or lung function. By increasing airway inflammation from oxidative-stress, tobacco smoking appears to interact with other chemical or physical factors elicited during sea navigation. Precisely what these factors are deserves further investigation.

Chronic cough due to occupational factors

Within the large variety of subtypes of chronic cough, either defined by their clinical or pathogenetic causes, occupational chronic cough may be regarded as one of the most preventable forms of the disease. Next to obstructive airway diseases such as asthma or chronic obstructive pulmonary disease, which are sometimes concomitant with chronic cough, this chronic airway disease gains importance in the field of occupational medicine since classic fiber-related occupational airway diseases will decrease in the future.

Apart from acute accidents and incidental exposures which may lead to an acute form of cough, there are numerous sources for the development of chronic cough within the workplace. Over the last years, a large number of studies has focused on occupational causes of respiratory diseases and it has emerged that chronic cough is one of the most prevalent work-related airway diseases. Best-known examples of occupations related to the development of cough are coal miners, hard-rock miners, tunnel workers, or concrete manufacturing workers.

As chronic cough is often based on a variety of non-occupational factors such as tobacco smoke, a distinct separation into either occupational or personally -evoked can be difficult. However, revealing the occupational contribution to chronic cough and to the symptom cough in general, which is the commonest cause for the consultation of a physician, can significantly lead to a reduction of the socioeconomic burden of the disease.

Surveillance for isocyanate asthma: a model based cost effectiveness analysis

AIMS

Because logistical and financial obstacles impede using large prospective cohort studies, surveillance decisions in occupational settings must often be made without evidence of relative benefits and costs. Using the example of isocyanate induced asthma, the most commonly reported immune mediated occupational asthma, the authors developed a model based approach to evaluate the costs and benefits of surveillance from both an employer and a societal perspective.

METHODS

The authors used a mathematical simulation model of isocyanate asthma to compare annual surveillance to passive case finding. Outcome measures included symptom free days (SFD), quality adjusted life years (QALY), direct costs, productivity losses, and incremental cost effectiveness ratio (CER), measured from the employer and the societal perspectives. Input data were obtained from a variety of published sources.

RESULTS

For 100,000 exposed workers, surveillance resulted in 683 fewer cases of disability over 10 years. Surveillance conferred benefits at an incremental cost of 24,000 dollars/QALY (employer perspective; 13.33 dollars/SFD) and was cost saving from the societal perspective. Results were sensitive to assumptions about sensitisation rate, removal rates, and time to diagnosis, but not to assumptions about therapy costs and disability rates.

CONCLUSIONS

Baseline results placed the CER for surveillance for isocyanate asthma within the acceptable range. Costs from the societal and employer perspective differed substantially with a more attractive CER from the societal perspective, suggesting opportunities for employer/societal cost sharing. The analysis demonstrates the value of a model based approach to evaluate the cost effectiveness of surveillance programmes for isocyanate asthma, and to inform shared decision making among clinicians, patients, employers, and society. Such a modeling approach may be applicable to surveillance programmes for other work related conditions.