Publications

BACKGROUND

Professional use of hypochlorite (bleach) has been associated with respiratory symptoms. Bleach is capable of inactivating allergens, and there are indications that its domestic use may reduce the risk of allergies in children.

OBJECTIVE

To study the associations between household use of bleach and atopic sensitization, allergic diseases, and respiratory health status in adults.

METHODS

We identified 3626 participants of the European Community Respiratory Health Survey II in 10 countries who did the cleaning in their homes and for whom data on specific serum IgE to 4 environmental allergens were available. Frequency of bleach use and information on respiratory symptoms were obtained in face-to-face interviews. House dust mite and cat allergens in mattress dust were measured in a subsample. Associations between the frequency of bleach use and health outcomes were evaluated by using multivariable mixed logistic regression analyses.

RESULTS

The use of bleach was associated with less atopic sensitization (odds ratio [OR], 0.75; 95% CI, 0.63-0.89). This association was apparent for specific IgE to both indoor (cat) and outdoor (grass) allergens, and was consistent in various subgroups, including those without any history of respiratory problems (OR, 0.85). Dose-response relationships (P < .05) were apparent for the frequency of bleach use and sensitization rates. Lower respiratory tract symptoms, but not allergic symptoms, were more prevalent among those using bleach 4 or more days per week (OR, 1.24-1.49). The use of bleach was not associated with indoor allergen concentrations.

CONCLUSION

People who clean their homes with hypochlorite bleach are less likely to be atopic but more likely to have respiratory symptoms.

Work-related asthma is common among adult asthmatics, either asthma initially caused by work (occupational asthma) or pre-existing asthma worsened by work factors (work-exacerbated asthma). Appropriate management depends on both correct diagnosis and on recognition of etiology. Following a systematic literature review, the American College of Chest Physicians enpaneled a group of experts that reviewed this material, extended the literature review, and developed a "Consensus Statement on the Diagnosis, and Management of Work-Related Asthma", published in 2008. This article addresses the main practical aspects of that Consensus Statement, including clinical clues to diagnosis of work-related asthma from the medical history, exposure assessment, targeted diagnostic tests, and directed patient management. The range and importance of preventive measures are also addressed.

BACKGROUND

Psychologic factors affect how patients with COPD respond to attempts to improve their self-management skills. Learned helplessness may be one such factor, but there is no validated measure of helplessness in COPD.

METHODS

We administered a new COPD Helplessness Index (CHI) to 1,202 patients with COPD. Concurrent validity was assessed through association of the CHI with established psychosocial measures and COPD severity. The association of helplessness with incident COPD exacerbations was then examined by following subjects over a median 2.1 years, defining COPD exacerbations as COPD-related hospitalizations or ED visits.

RESULTS

The CHI demonstrated internal consistency (Cronbach alpha = 0.75); factor analysis was consistent with the CHI representing a single construct. Greater CHI-measured helplessness correlated with greater COPD severity assessed by the BODE (Body-mass, Obstruction, Dyspnea, Exercise) Index (r = 0.34; P < .001). Higher CHI scores were associated with worse generic (Short Form-12, Physical Component Summary Score) and respiratory-specific (Airways Questionnaire 20) health-related quality of life, greater depressive symptoms, and higher anxiety (all P < .001). Controlling for sociodemographics and smoking status, helplessness was prospectively associated with incident COPD exacerbations (hazard ratio = 1.31; P < .001). After also controlling for the BODE Index, helplessness remained predictive of COPD exacerbations among subjects with BODE Index

CONCLUSIONS

The CHI is an internally consistent and valid measure, concurrently associated with health status and predictively associated with COPD exacerbations. The CHI may prove a useful tool in analyzing differential clinical responses mediated by patient-centered attributes.

BACKGROUND

Although chronic obstructive pulmonary disease (COPD) is a common cause of death and disability, little is known about the effects of socioeconomic status (SES) and race-ethnicity on health outcomes.

METHODS

The aim of this study is to determine the independent impacts of SES and race-ethnicity on COPD severity status, functional limitations and acute exacerbations of COPD among patients with access to healthcare. Data were used from the Function, Living, Outcomes and Work cohort study of 1202 Kaiser Permanente Northern California Medical Care Plan members with COPD.

RESULTS

Lower educational attainment and household income were consistently related to greater disease severity, poorer lung function and greater physical functional limitations in cross-sectional analysis. Black race was associated with greater COPD severity, but these differences were no longer apparent after controlling for SES variables and other covariates (comorbidities, smoking, body mass index and occupational exposures). Lower education and lower income were independently related to a greater prospective risk of acute COPD exacerbation (HR 1.5; 95% CI 1.01 to 2.1; and HR 2.1; 95% CI 1.4 to 3.4, respectively).

CONCLUSION

Low SES is a risk factor for a broad array of adverse COPD health outcomes. Clinicians and disease management programs should consider SES as a key patient-level marker of risk for poor outcomes.

BACKGROUND

Both disability and depression are common in COPD, but limited information is available on the time-ordered relationship between increases in disability and depression onset.

METHODS

Subjects were members of a longitudinal cohort with self-reported physician-diagnosed COPD, emphysema, or chronic bronchitis. Data were collected through three annual structured telephone interviews (T1, T2, and T3). Depression was defined as a score >/= 4 on the Geriatric Depression Scale Short Form (S-GDS). Disability was measured with the Valued Life Activities (VLA) scale; three disability scores were calculated: percent of VLAs unable to perform, percent of VLAs affected (unable to perform or with some degree of difficulty), and mean VLA difficulty rating. Disability increases were defined as a 0.5 SD increase in disability score between T1 and T2. Multiple logistic regression analyses estimated the risk of T3 depression following a T1 to T2 disability increase for the total cohort and then excluding individuals who met the depression criterion at T1 or T2.

RESULTS

Approximately 30% of subjects met the depression criterion each year. Eight percent to 19% experienced a T1 to T2 disability increase, depending on the disability measure. Including all cohort members and controlling for baseline S-GDS scores, T1 to T2 increases in disability yielded a significantly elevated risk of T3 depression (% affected odds ratio [OR] =3.6; 95% CI, [1.7, 7.7]; % unable OR = 6.1 [17, 21.8]; mean difficulty OR= 3.6 [1.7, 8.0]). Omitting individuals depressed at T1 or T2 yielded even stronger risk estimates for % unable (OR = 13.4 [2.0, 91.4]) and mean difficulty (OR = 3.9 [1.3, 11.8]).

CONCLUSIONS

Increases in VLA disability are strongly predictive of the onset of depression.

Depression and chronic obstructive pulmonary disease (COPD) are major causes of disability. Identifying COPD patients at risk for depression would facilitate the alleviation of an important comorbidity conferring additional risk for poor outcomes. The purpose of this study was to determine the utility of a brief screening measure, the 15-item Geriatric Depression Scale (GDS-15), in detecting the mood disorders in persons with COPD. This is a cross-sectional study of 188 persons with COPD, stratified by age (65 and older versus less than 65) and COPD severity using Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging. Screening cut-points were empirically derived using threshold selection methods and receiver operating characteristic (ROC) curves were estimated. The GDS-15 was used as a screening measure and diagnoses of Major Depressive Disorder (MDD) or other mood disorders were determined using a "gold standard" standardized structured clinical interview. Of the 188 persons with COPD, 25% met criteria for any mood disorder and 11% met criteria for MDD. Optimal threshold estimations suggested a GDS cut score of 5, which yielded adequate sensitivity and specificity in detecting MDD (81% and 87%, respectively) and correctly classified 86% of participants. To detect the presence of any mood disorder, a cut score of 4 was suggested yielding sensitivity and specificity of 67% and 82%, respectively; correctly classifying 79%. These results suggest that mood disorders are relatively common among persons with COPD. The GDS-15 is a useful screening measure to identify patients at risk for depression.

BACKGROUND

A comprehensive survey-based COPD severity score has usefulness for epidemiologic and health outcomes research. We previously developed and validated the survey-based COPD Severity Score without using lung function or other physiologic measurements. In this study, we aimed to further validate the severity score in a different COPD cohort and using a combination of patient-reported and objective physiologic measurements.

METHODS

Using data from the Function, Living, Outcomes, and Work cohort study of COPD, we evaluated the concurrent and predictive validity of the COPD Severity Score among 1,202 subjects. The survey instrument is a 35-point score based on symptoms, medication and oxygen use, and prior hospitalization or intubation for COPD. Subjects were systemically assessed using structured telephone survey, spirometry, and 6-min walk testing.

RESULTS

We found evidence to support concurrent validity of the score. Higher COPD Severity Score values were associated with poorer FEV(1) (r = -0.38), FEV(1)% predicted (r = -0.40), Body mass, Obstruction, Dyspnea, Exercise Index (r = 0.57), and distance walked in 6 min (r = -0.43) (P < .0001 in all cases). Greater COPD severity was also related to poorer generic physical health status (r = -0.49) and disease-specific health-related quality of life (r = 0.57) (P < .0001). The score also demonstrated predictive validity. It was also associated with a greater prospective risk of acute exacerbation of COPD defined as ED visits (hazard ratio [HR], 1.31; 95% CI, 1.24-1.39), hospitalizations (HR, 1.59; 95% CI, 1.44-1.75), and either measure of hospital-based care for COPD (HR, 1.34; 95% CI, 1.26-1.41) (P < .0001 in all cases).

CONCLUSION

The COPD Severity Score is a valid survey-based measure of disease-specific severity, both in terms of concurrent and predictive validity. The score is a psychometrically sound instrument for use in epidemiologic and outcomes research in COPD.

BACKGROUND

Psychological functioning is an important determinant of health outcomes in chronic lung disease. To better define the role of anxiety in chronic obstructive pulmonary disease (COPD), a study was conducted of the inter-relations between anxiety and COPD in a large cohort of subjects with COPD and a matched control group.

METHODS

Data were used from the FLOW (Function, Living, Outcomes, and Work) cohort of patients with COPD (n=1202) and matched controls without COPD (n=302). Anxiety was measured using the Anxiety subscale of the Hospital Anxiety and Depression Scale.

RESULTS

COPD was associated with a greater risk of anxiety in multivariable analysis (OR 1.85; 95% CI 1.072 to 3.18). Among patients with COPD, anxiety was related to poorer health outcomes including worse submaximal exercise performance (less distance walked during the 6-min walk test: -66.3 feet for anxious vs non-anxious groups; 95% CI -127.3 to -5.36) and a greater risk of self-reported functional limitations (OR 2.41; 95% CI 1.71 to 3.41). Subjects with COPD with anxiety had a higher longitudinal risk of COPD exacerbation in Cox proportional hazards analysis after controlling for covariates (HR 1.39; 95% CI 1.007 to 1.90).

CONCLUSION

COPD is associated with a higher risk of anxiety. Once anxiety develops among patients with COPD, it is related to poorer health outcomes. Further research is needed to determine whether systematic screening and treatment of anxiety in COPD will improve health outcomes and prevent functional decline and disability.

PURPOSE

The purpose of this study was to delineate the effect of chronic obstructive pulmonary disease (COPD) on a broad range of valued life activities (VLAs) and make comparisons to effects of other airways conditions.

METHODS

We used cross-sectional data from a population-based, longitudinal study of US adults with airways disease. Data were collected by telephone interview. VLA disability was compared among 3 groups defined by reported physician diagnoses: COPD/emphysema, chronic bronchitis, and asthma. Multiple regression analyses were conducted to identify independent predictors of VLA disability.

RESULTS

About half of individuals with COPD were unable to perform at least 1 VLA; almost all reported at least 1 VLA affected. The impact among individuals with chronic bronchitis and asthma was less but still notable: 74%-84% reported at least 1 activity affected, and about 15% were unable to perform at least 1 activity. In general, obligatory activities were the least affected. Symptom measures and functional limitations were the strongest predictors of disability, independent of respiratory condition.

CONCLUSION

VLA disability is common among individuals with COPD. Obligatory activities are less affected than committed and discretionary activities. A focus on obligatory activities, as is common in disability studies, would miss a great deal of the impact of these conditions. Because individuals are often referred to pulmonary rehabilitation as a result of dissatisfaction with ability to perform daily activities, VLA disability may be an especially relevant outcome for rehabilitation.

BACKGROUND

Diverse environmental exposures, studied separately, have been linked to health outcomes in adult asthma, but integrated multi-factorial effects have not been modeled. We sought to evaluate the contribution of combined social and physical environmental exposures to adult asthma lung function and disease severity.

METHODS

Data on 176 subjects with asthma and/or rhinitis were collected via telephone interviews for sociodemographic factors and asthma severity (scored on a 0-28 point range). Dust, indoor air quality, antigen-specific IgE antibodies, and lung function (percent predicted FEV1) were assessed through home visits. Neighborhood socioeconomic status, proximity to traffic, land use, and ambient air quality data were linked to the individual-level data via residential geocoding. Multiple linear regression separately tested the explanatory power of five groups of environmental factors for the outcomes, percent predicted FEV1 and asthma severity. Final models retained all variables statistically associated (p < 0.20) with each of the two outcomes.

RESULTS

Mean FEV1 was 85.0 +/- 18.6%; mean asthma severity score was 6.9 +/- 5.6. Of 29 variables screened, 13 were retained in the final model of FEV1 (R2 = 0.30; p < 0.001) and 15 for severity (R2 = 0.16; p < 0.001), including factors from each of the five groups. Adding FEV1 as an independent variable to the severity model further increased its explanatory power (R2 = 0.25).

CONCLUSIONS

Multivariate models covering a range of individual and environmental factors explained nearly a third of FEV1 variability and, taking into account lung function, one quarter of variability in asthma severity. These data support an integrated approach to modeling adult asthma outcomes, including both the physical and the social environment.