Publications

This review critically evaluates the recent scientific literature relevant to occupational risk factors for chronic obstructive pulmonary disease (COPD) and chronic bronchitis. The 2003 American Thoracic Society statement on the occupational contribution to the burden of airway disease synthesized relevant data on this topic through 1999. Since 2000, 14 separate studies have published values or provide data that allow estimation of the population attributable risk per cent (PAR%) for the proportion of chronic bronchitis or COPD due to work-related factors. Based on data since 2000, the median PAR% value for both chronic bronchitis and COPD is 15%. A number of additional studies have been published that underscore the association between specific occupational exposures and airflow obstruction. In addition, data are emerging that indicate the extent to which COPD is a cause of work disability; limited data raise the possibility that among those with occupational COPD, disability may be even more prominent. This review supports previous analyses concluding that there is a causal association between work-related exposures and COPD.

INTRODUCTION

As part of a larger study assessing the covariates and outcomes of GHB use, we developed a telephone-survey instrument for hospitalized GHB exposed patients identified through poison control center surveillance and for self-identified GHB users recruited from the general public.

METHODS

We used an iterative review process with an interdisciplinary team, including pharmacists, a physician, and a medical anthropologist. In designing the structured, telephone-survey instrument, we prioritized inclusion of validated, drug-specific, and generic questionnaire batteries or individual items related to GHB or to other drugs of abuse. Only one published survey instrument specific to GHB use was identified, which we extensively expanded and modified. We also developed a number of GHB-specific items new to this survey. Finally, we included items from the National Survey on Drug Use & Health, CAGE questionnaire items on alcohol abuse, the SF-12 instrument, and selected National Health Interview items.

RESULTS

The final questionnaire consisted of 272 content items, the majority of which required simple yes or no responses. The bulk of the items (74%) were GHB-specific. The questionnaire was easily administered using computer-assisted telephone interview (CATI) software. A total of 131 interviews were administered with a mean administration time of 33+/-10 minutes. The instrument can also be used in other interview formats.

CONCLUSION

Developing a successful questionnaire calls for a multidisciplinary and systematic process. Structured, telephone administered surveys are particularly suited to expand and explore the basic information obtained by poison centers for case management.

BACKGROUND

The combined effect of socioeconomic, organizational, psychosocial, and physical factors on work-related musculoskeletal disorders (WRMSDs) were studied in a heterogeneous, socioeconomically diverse sample (cases and their matched referents) of hospital workers.

METHODS

Cases were defined by a new acute or cumulative work-related musculoskeletal injury; referents were matched by job group, shift length, or at random. Information was obtained through telephone interviews and on-site ergonomics observation. Questionnaire items included sociodemographic variables, lost work time, work effectiveness, health status, pain/disability, and psychosocial working conditions using Effort Reward Imbalance (ERI) and Demand-Control (DC) models. Two multivariate models were tested: Model 1 included occupation as a predictor; Model 2 included education-income as a predictor.

RESULTS

Cases reported greater pain, disability, lost time, and decreased work effectiveness than the referents. Model 1 was statistically significant for neck/upper extremity injury (Chi-square = 19.3, P = 0.01), back/lower extremity injury (Chi-square = 14.0, P = 0.05), and all injuries combined (Chi-square = 25.4, P = 0.001). "Other Clinical" occupations (34% mental health workers) had the highest risk of injury (OR 4.5: 95%CI, 1.7-12.1) for all injuries. The ERI ratio was a significant predictor for neck and upper extremity (OR 1.5: 95%CI, 1.1-1.9) and all injuries (OR 1.3; 95%CI, 1.04-1.5), per SD change in score.

CONCLUSIONS

In this study, the risk of WRMSDs was more strongly influenced by specific psychosocial and physical job-related exposures than by broad socioeconomic factors such as education and income.

BACKGROUND

Current practice guidelines emphasize the importance of attaining asthma control. We sought to quantify the degree of quality-of-life impairment associated with different levels of asthma control.

METHODS

We analyzed prospective data for 987 adults in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. Asthma control was assessed by using the Asthma Therapy Assessment Questionnaire, a validated index of control problems ranging from 0 to 4. Disease-specific quality of life and preference-based health utilities were assessed after 12 months of follow-up by using the Mini-Asthma Quality of Life Questionnaire (AQLQ) and EuroQoL 5-D (EQ-5D). We used multiple linear regression to model the relationship between asthma control and the AQLQ and EQ-5D while controlling for severity classification and lung function.

RESULTS

Asthma control varied widely, even within a population with predominantly moderate-to-severe disease. An inverse relationship was observed between the number of asthma control problems and quality of life. Specifically, poorer control at baseline predicted worse AQLQ and EQ-5D scores at follow-up. Asthma control remained an independent predictor of disease-specific quality of life and general health in multivariate models and was a better longitudinal predictor of health status than asthma severity at baseline.

CONCLUSION

Poor asthma control is associated with a substantial degree of impairment and predicts quality of life at 12 months, even after taking baseline asthma severity into account.

CLINICAL IMPLICATIONS

Self-assessed measures of asthma control might help to identify and manage those patients at greatest risk for future health impairment.

BACKGROUND

The role of exposure to substances in the workplace in new-onset asthma is not well characterised in population-based studies. We therefore aimed to estimate the relative and attributable risks of new-onset asthma in relation to occupations, work-related exposures, and inhalation accidents.

METHODS

We studied prospectively 6837 participants from 13 countries who previously took part in the European Community Respiratory Health Survey (1990-95) and did not report respiratory symptoms or a history of asthma at the time of the first study. Asthma was assessed by methacholine challenge test and by questionnaire data on asthma symptoms. Exposures were defined by high-risk occupations, an asthma-specific job exposure matrix with additional expert judgment, and through self-report of acute inhalation events. Relative risks for new onset asthma were calculated with log-binomial models adjusted for age, sex, smoking, and study centre.

FINDINGS

A significant excess asthma risk was seen after exposure to substances known to cause occupational asthma (Relative risk=1.6, 95% CI 1.1-2.3, p=0.017). Risks were highest for asthma defined by bronchial hyper-reactivity in addition to symptoms (2.4, 1.3-4.6, p=0.008). Of common occupations, a significant excess risk of asthma was seen for nursing (2.2, 1.3-4.0, p=0.007). Asthma risk was also increased in participants who reported an acute symptomatic inhalation event such as fire, mixing cleaning products, or chemical spills (RR=3.3, 95% CI 1.0-11.1, p=0.051). The population-attributable risk for adult asthma due to occupational exposures ranged from 10% to 25%, equivalent to an incidence of new-onset occupational asthma of 250-300 cases per million people per year.

INTERPRETATION

Occupational exposures account for a substantial proportion of adult asthma incidence. The increased risk of asthma after inhalation accidents suggests that workers who have such accidents should be monitored closely.

We investigated whether perceived neighborhood problems (NP) predicted changes over a 2-year period in asthma-specific quality of life (QOL), physical functioning (PF), and depressive symptomology (DEP) in a longitudinal cohort of 340 adults with asthma. There is a threshold and plateau effect between NP and PF, such that NP do not affect changes in PF until the problems reach the level of Quartile 3. People who had NP scores in Quartile 3 had lower PF compared to people who reported NP in Quartiles 1 or 2 (mean difference -3.09). High NP also predicted over two-fold odds of high DEP (Center for Epidemiological Studies Depression [CES-D] score > or = 16) at follow-up (odds ratio=2.34; 95% confidence interval: 1.09-5.00). NP did not predict decline in QOL. Analyses adjusted for demographics, asthma severity, and baseline value of the health outcome.

BACKGROUND

Morbidity from asthma disproportionately affects black people. Whether this excess morbidity is fully explained by differences in asthma severity, access to care, or socioeconomic status (SES) is unknown.

METHODS

We assessed whether there were racial disparities in asthma management and outcomes in a managed care organization that provides uniform access to health care and then determined to what degree these disparities were explained by differences in SES, asthma severity, and asthma management. We prospectively studied 678 patients from a large, integrated health care delivery system. Patients who had been hospitalized for asthma were interviewed after discharge to ascertain information about asthma history, health status, and SES. Small-area socioeconomic data were ascertained by means of geocoding and linkage to the US Census 2000. Patients were followed up for subsequent emergency department (ED) visits or hospitalizations (median follow-up, 1.9 years).

RESULTS

Black race was associated with a higher risk of ED visits (hazard ratio [HR], 1.93; 95% confidence interval [CI], 1.39-2.66) and hospitalizations (HR, 1.89; 95% CI, 1.30-2.76). This finding persisted after adjusting for SES and differences in asthma therapy (adjusted HR for ED visits, 1.73; 95% CI, 1.07-2.81; and adjusted HR for hospitalizations, 2.01; 95% CI, 1.33-3.02).

CONCLUSIONS

Even in a health care setting that provides uniform access to care, black race was associated with worse asthma outcomes, including a greater risk of ED visits and hospitalizations. This association was not explained by differences in SES, asthma severity, or asthma therapy. These findings suggest that genetic differences may underlie these racial disparities.

BACKGROUND

Inequalities in the use of new medications may contribute to health disparities. We analyzed socioeconomic gradients in the use of tiotropium for chronic obstructive pulmonary disease (COPD).

METHODS

In a cohort of adults with COPD aged > or = 55 years identified through population-based sampling, we elicited questionnaire responses on demographics, socioeconomic status (SES; lower SES defined as high school education or less or annual household income < US $20,000), and medication use and other clinical variables. In a subset we obtained pulmonary function testing. We used multiple logistic regression analysis to estimate the associations between SES and tiotropium use in COPD, adjusting for disease severity measured by a COPD Severity Score.

RESULTS

Of 427 subjects, 44 (10.3%) reported using tiotropium in 2006. Adjusting for COPD severity, lower SES was associated with reduced odds of tiotropium use (OR 0.3; 95% CI 0.1-0.7; p = 0.005). Among the subset with lung function data (n = 95), after including COPD Global Obstructive Lung Disease (GOLD) Stage > or = 2 in the model, lower SES remained associated with reduced odds oftiotropium use (OR 0.03; 95% CI < 0.001-0.7; p = 0.03). Including forced expiratory volume in one second in the model as a continuous variable instead of GOLD Stage > or = 2 yielded similar results for lower SES (OR 0.1; 95% CI < 0.001-0.5; p = 0.02).

CONCLUSION

There was a strong SES gradient in tiotropium use such that there was less use with lower SES. To the extent that this is an efficacious medication for COPD, this gradient represents a potential source of health disparities.

OBJECTIVES

Asthma can be associated with substantial productivity loss and activity impairment, particularly among those with the most severe disease. We sought to assess the performance characteristics of an asthma-specific adaptation of the Work Productivity and Activity Impairment Questionnaire (WPAI:Asthma) in patients with either severe or difficult-to-treat asthma.

METHODS

We analyzed 2529 subjects from The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. The WPAI:Asthma was administered at baseline and at 12 months. Asthma control and quality-of-life were simultaneously assessed using the Asthma Therapy Assessment Questionnaire and Mini-Asthma Quality-of-Life Questionnaire, respectively.

RESULTS

Severe versus mild-to-moderate asthma was associated with a greater percentage of impairment at work (28% vs. 14%), at school (32% vs. 18%), and in daily activities (41% vs. 21%). At baseline, greater asthma control problems correlated with higher levels of impairment as measured by the WPAI (work: r = 0.54, school: r = 0.37, activity: r = 0.55). Over the 12-month follow-up period, improved quality-of-life correlated with decreased levels of impairment (work: r = -0.42, school: r = -0.36, activity: r = -0.48). In multivariate analyses, greater than 10% overall work impairment at baseline predicted emergency visits (OR 2.6 [1.6, 4.0]) and hospitalization (OR 4.9 [1.8, 13.1]) at 12 months.

CONCLUSIONS

The WPAI:Asthma correlates with other self-reported asthma outcomes in the expected manner and predicts health-care utilization at 12 months when administered to patients with severe or difficult-to-treat asthma.