Publications

STUDY OBJECTIVES

To compare kinds and amounts of health care used by adults with asthma in managed care and fee-for-service settings.

DESIGN

Cross-sectional structured telephone survey of Northern California adults with asthma from random samples of pulmonologists, allergist-immunologists, family practitioners, and from a random sample of the non-institutionalized population.

MEASUREMENTS

Validated measures of kind of health insurance plans, kinds and amounts of services used for asthma and other reasons, demographic characteristics, severity of asthma, comorbidity, and overall health and functional status.

RESULTS

Eighty one percent of the 416 adults with asthma studied were in some form of managed care (75% in HMOs and 6% in PPOs). Those in managed care (MC) and fee-for-service (FFS) did not differ substantively in the proportion with a regular source or principal provider of asthma care, with a peak flow meter or action plan, having received instructions in the use of an inhaler, reporting current use of inhaled beta-agonists, home nebulized beta-agonists, or inhaled steroids, or reporting ER visits or flu shots in the year prior to interview. Persons with asthma in MC reported significantly fewer total physician visits (after adjustment, 4.3 MC, 7.1 FFS, difference = 2.8, 95% CI -5.4, -0.1), principally because those in MC had many fewer visits to allergist-immunologists (after adjustment 4.9 MC, 21.4 FFS, difference = -16.5, 95% CI -27.8, -5.3). The two groups did not differ significantly in the proportion with asthma-related or nonasthma hospital admissions.

CONCLUSIONS

Persons with asthma in fee-for-service settings reported a greater number of certain kinds of ambulatory visits, particularly visits to allergist-immunologists, for their asthma than those in managed care, but did not differ in the use of the hospital for their asthma and in nonasthma care.

BACKGROUND

Psychosocial working conditions are likely to contribute to work-related musculoskeletal disorders (WRMSDs), but a lack of standardized measurement tools reflects both the theoretical and methodological limitations of current research.

METHODS

An interdisciplinary team including biomedical, behavioral, and social science researchers used an iterative process to adapt existing instruments for an interviewer-administered questionnaire assessing psychosocial workplace exposure related to musculoskeletal disorders.

RESULTS

The resulting questionnaire included measures of psychosocial workplace factors based on two theoretical models (the demand-control-support and the effort-reward imbalance models), supplemented by the additional constructs of "emotional demands," and "experiences of discrimination." Other psychosocial and physical measures selected for questionnaire inclusion address physical workload, sociodemographic and anthropometric characteristics, social relations and life events, health behaviors, and physical and psychological health.

CONCLUSION

Using an interdisciplinary approach facilitated the development of a comprehensive questionnaire inclusive of key measures of psychosocial factors that may play a role in the complex mechanisms leading to WRMSDs.

BACKGROUND AND AIMS

Despite recognition that occupational exposures may make a substantive contribution to the aetiology of COPD, little is known about the potential role of work related factors in COPD related health outcomes.

METHODS

Prospective cohort study using structured telephone interviews among a random sample of adults aged 55-75 reporting a COPD condition (emphysema, chronic bronchitis, or COPD). Using multivariate models adjusting for smoking and demographic factors, the separate and combined associations were estimated between occupational exposure to vapours, gas, dust, or fumes (VGDF) and leaving work due to lung disease (respiratory related work disability) with health outcomes and utilisation ascertained at one year follow up.

RESULTS

Of 234 subjects, 128 (55%) reported exposure to VGDF on their longest held jobs, 58 (25%) reported respiratory related work disability, and 38 (16%) subjects reported both. Combined exposure to VGDF and respiratory related work disability (rather than either factor alone) was associated with the greatest risk at follow up of frequent (everyday) restricted activity days attributed to a breathing or lung condition (OR 3.8; 95% CI 1.4 to 10.1), emergency department (ED) visit (OR 3.9; 95% CI 1.4 to 10.5), and hospitalisation (OR 7.6; 95% CI 1.8 to 32).

CONCLUSIONS

Among persons with COPD, past occupational exposures and work disability attributed to lung disease, particularly in combination, appear to be risk factors for adverse health related outcomes.

BACKGROUND

Factors affecting health-related quality of life (HRQOL) in adult rhinitis have not been well described.

OBJECTIVE

To understand how symptom severity, physical functioning, psychological distress, and perceived control of disease relate to HRQOL in a population-based sample of adults with rhinitis.

METHODS

We conducted telephone interviews in 109 adults with rhinitis recruited via random digit dialing. We assessed HRQOL by using the Rhinosinusitis Disability Index, physical functioning by using the physical component score of the Short Form-12, and psychological distress by using the Center for Epidemiologic Studies Depression Scale. To evaluate the role of patient-perceived control of disease in rhinitis, we developed a new 8-item instrument, the Perceived Control of Rhinitis Questionnaire.

RESULTS

Lower HRQOL correlated with greater symptom severity ( r=0.57), poorer physical functioning ( r=-0.41), greater psychological distress ( r=0.44), and less perceived control ( r=-0.53). In a multivariate model, symptom severity ( P < .001), psychological distress ( P <.001), and perceived control ( P <.001) were all independent predictors of HRQOL. Adding functional and psychosocial measures to a base model with demographics and disease severity explained an additional 26% of variance in HRQOL.

CONCLUSIONS

Although disease severity is an important factor in HRQOL, psychosocial factors, such as perceived control of disease, explain a substantial amount of the variability in HRQOL among adults with rhinitis.

OBJECTIVE

We sought to better use qualitative approaches in occupational health research and integrate them with quantitative methods.

METHODS

We systematically reviewed, selected, and adapted qualitative research methods as part of a multisite study of the predictors and outcomes of work-related musculoskeletal disorders among hospital workers in two large urban tertiary hospitals.

RESULTS

The methods selected included participant observation; informal, open-ended, and semistructured interviews with individuals or small groups; and archival study. The nature of the work and social life of the hospitals and the foci of the study all favored using more participant observation methods in the case study than initially anticipated.

CONCLUSIONS

Exploiting the full methodological spectrum of qualitative methods in occupational health is increasingly relevant. Although labor-intensive, these approaches may increase the yield of established quantitative approaches otherwise used in isolation.

OBJECTIVE

We sought to study the combined effects of multiple home indoor environmental exposures in adult asthma and rhinitis.

METHODS

We studied 226 adults with asthma and rhinitis by structured interviews and home assessments. Environmental factors included dust allergen, endotoxin and glucan concentrations, and indoor air quality (IAQ) variables. Outcomes included forced expiratory volume in 1 second (FEV1) percent predicted, Severity of Asthma Score (SAS), Short-Form (SF)-12 Physical Component Scale (PCS), and asthma Quality of Life (QOL) score.

RESULTS

House dust-associated exposures together with limited IAQ variables were related to FEV1 % predicted (R = 0.24; P = 0.0001) and SAS (R = 0.18; P = 0.007). IAQ and limited dust variables were associated with SF-12 PCS (R = 0.15; P = 0.02), but not QOL (R = 0.13; P = 0.16).

CONCLUSIONS

The home environment is strongly linked to lung function, health status, and disease severity in adult asthma and rhinitis.

The diurnal rhythm of cortisol secretion in chronic disease can reflect the interactions between exogenous and endogenous factors. Exogenous glucocorticoid use may impact salivary cortisol measurements, but this has not been well-studied in ambulatory settings. In this report salivary cortisol levels were used to evaluate aspects of the diurnal rhythm of cortisol secretion within an ambulatory population of patients with asthma and allergic rhinitis. 183 persons with asthma with or without concomitant rhinitis and 34 persons with rhinitis alone were asked to collect at home, two saliva samples, 30 min after awakening and 12h later. The salivary cortisol levels were quantified by enzyme immunoassay. The recent use of glucocorticoids in the study group was determined by interview and direct examination of medications. We report that the median salivary cortisol levels 30 min post-awakening significantly differed by exogenous steroid status: no glucocorticoid use (n = 91), 10.1 nmol/l; nasal gluco-corticoid use alone (n = 25), 11.4 nmol/l; inhaled glucocorticoids (with or without concomitant nasal glucocorticoids; n = 76), 9.0 nmol/l; systemic glucocorticoids (n = 17), 4.0 nmol/l; (P = 0.02). 12-h post-awakening salivary cortisol values among the groups were similar (P = 0.85). The median 30-min post-awakening cortisol differed significantly by type and amount of inhaled steroid used: non-fluticasone users (n = 21), 11.5 nmol/l; lower dose fluticasone (<800 microg per day, n = 35); 9.2 nmol/l; and higher dose fluticasone (> or =800 microg, n=20), 5 nmol/l; (P=0.01). We conclude that in an ambulatory setting, exogenous glucocorticoid use can decrease the 30 min post-awakening but not the 12-h post-awakening salivary cortisol levels, an effect that should be taken into account in assessing the effects of other potential determinants on cortisol secretion.

BACKGROUND

Exposure to environmental tobacco smoke (ETS), which contains potent respiratory irritants, may lead to chronic airway inflammation and obstruction. Although ETS exposure appears to cause asthma in children and adults, its role in causing COPD has received limited attention in epidemiologic studies.

METHODS

Using data from a population-based sample of 2,113 U.S. adults aged 55 to 75 years, we examined the association between lifetime ETS exposure and the risk of developing COPD. Participants were recruited from all 48 contiguous U.S. states by random digit dialing. Lifetime ETS exposure was ascertained by structured telephone interview. We used a standard epidemiologic approach to define COPD based on a self-reported physician diagnosis of chronic bronchitis, emphysema, or COPD.

RESULTS

Higher cumulative lifetime home and work exposure were associated with a greater risk of COPD. The highest quartile of lifetime home ETS exposure was associated with a greater risk of COPD, controlling for age, sex, race, personal smoking history, educational attainment, marital status, and occupational exposure to vapors, gas, dusts, or fumes during the longest held job (OR 1.55; 95% CI 1.09 to 2.21). The highest quartile of lifetime workplace ETS exposure was also related to a greater risk of COPD (OR 1.36; 95% CI 1.002 to 1.84). The population attributable fraction was 11% for the highest quartile of home ETS exposure and 7% for work exposure.

CONCLUSION

ETS exposure may be an important cause of COPD. Consequently, public policies aimed at preventing public smoking may reduce the burden of COPD-related death and disability, both by reducing direct smoking and ETS exposure.

OBJECTIVE

To develop a comprehensive disease-specific COPD severity instrument for survey-based epidemiologic research.

STUDY DESIGN AND SETTING

Using a population-based sample of 383 US adults with self-reported physician-diagnosed COPD, we developed a disease-specific COPD severity instrument. The severity score was based on structured telephone interview responses and included five overall aspects of COPD severity: respiratory symptoms, systemic corticosteroid use, other COPD medication use, previous hospitalization or intubation, and home oxygen use. We evaluated concurrent validity by examining the association between the COPD severity score and three health status domains: pulmonary function, physical health-related quality of life (HRQL), and physical disability. Pulmonary function was available for a subgroup of the sample (FEV1, n = 49; peak expiratory flow rate [PEFR], n = 93).

RESULTS

The COPD severity score had high internal consistency reliability (Cronbach alpha = 0.80). Among the 49 subjects with FEV1 data, higher COPD severity scores were associated with poorer percentage of predicted FEV1 (r = - 0.40, p = 0.005). In the 93 subjects with available PEFR measurements, greater COPD severity was also related to worse percentage of predicted PEFR (r = - 0.35, p < 0.001). Higher COPD severity scores were strongly associated with poorer physical HRQL (r = - 0.58, p < 0.0001) and greater restricted activity attributed to a respiratory condition (r = 0.59, p < 0.0001). Higher COPD severity scores were also associated with a greater risk of difficulty with activities of daily living (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.8 to 3.0) and inability to work (OR, 4.2; 95% CI, 3.0 to 5.8).

CONCLUSION

The COPD severity score is a reliable and valid measure of disease severity, making it a useful research tool. The severity score, which does not require pulmonary function measurement, can be used as a study outcome or to adjust for disease severity.