STUDY OBJECTIVE

To analyze changes in gamma-hydroxybutyrate (GHB) case reporting, we review GHB or congener drug cases reported to the California Poison Control System, comparing these to other data sets.

METHODS

We identified cases from the California Poison Control System computerized database using standardized codes and key terms for GHB and congener drugs ("gamma butyrolactone," "1,4-butanediol," "gamma valerolactone"). We noted California Poison Control System date, caller and exposure site, patient age and sex, reported coingestions, and outcomes. We compared California Poison Control System data to case incidence from American Association of Poison Control Centers and Drug Abuse Warning Network data and drug use prevalence from National Institute for Drug Abuse survey data.

RESULTS

A total of 1,331 patients were included over the 5-year period (1999-2003). California Poison Control System-reported GHB exposures decreased by 76% from baseline (n=426) to the final study year (n=101). The absolute decrease was present across all case types, although there was a significant proportional decrease in routine drug abuse cases and an increase in malicious events, including GHB-facilitated sexual assault (P=.002). American Association of Poison Control Centers data showed a similar decrease from 2001 to 2003. Drug Abuse Warning Network incidence flattened from 2001 to 2002 and decreased sharply in 2003. National Institute for Drug Abuse survey time trends were inconsistent across age groups.

CONCLUSION

Based on the precipitous decrease in California Poison Control System case incidence for GHB during 5 years, the parallel trend in American Association of Poison Control Centers data, and a more recent decrease in Drug Abuse Warning Network cases, a true decrease in case incidence is likely. This could be due to decreased abuse rates or because fewer abusers seek emergency medical care. Case reporting may account for part of the decrease in the incidence of poison center contacts involving GHB.

Socio-economic status (SES) may affect health status in airway disease at the individual and area level. In a cohort of adults with asthma, rhinitis or both conditions, questionnaire-derived individual-level SES and principal components analysis (PCA) of census data for area-level SES factors were used. Regression analysis was utilised to study the associations among individual- and area-level SES for the following four health status measures: severity of asthma scores and the Short Form-12 Physical Component Scale (SF-12 PCS) (n = 404); asthma-specific quality of life (QoL) scores (n = 340); and forced expiratory volume in one second (FEV1) per cent predicted (n = 218). PCA yielded a two-factor solution for area-level SES. Factor 1 (lower area-level SES) was significantly associated with poorer SF-12 PCS and worse asthma QoL. These associations remained significant after adding individual-level SES. Factor 1 was also significantly associated with severity of asthma scores, but not after addition of the individual-level SES. Factor 2 (suburban area-level SES) was associated with lower FEV1 per cent predicted in combined area-level and individual SES models. In conclusion, area-level socio-economic status is linked to some, but not all, of the studied health status measures after taking into account individual-level socio-economic status.

OBJECTIVE

To estimate the duration of work life among persons reporting a physician's diagnosis of COPD, asthma, or rhinitis compared to those with select non-respiratory conditions or none and to delineate the factors associated with continuance of employment.

METHODS

Persons ages 55 to 75 reporting a physician's diagnosis of COPD, asthma, or rhinitis as well as those without any of these conditions were identified by random-digit dialing (RDD) in the continental U.S and administered a structured survey. We used Kaplan-Meier life table analysis to estimate the duration of work life among persons with and without the three conditions and Cox proportional hazard regression to examine the role of demographic and work characteristics in the proportion leaving employment in each time interval.

RESULTS

Persons with COPD, asthma, and rhinitis were no less likely than the remainder of the population to have ever worked, but those with COPD were less likely to be working when interviewed or as of age 65, whichever came first. As of age 55, only 62 percent of persons with COPD continued to work versus 72 and 78 percent of persons with asthma and rhinitis, respectively. Persons with COPD, asthma, and rhinitis all had an elevated risk of leaving work prior to age 65 relative to those without chronic conditions, with and without adjustment for demographic and work characteristics.

CONCLUSION

COPD and to a lesser extent asthma and rhinitis were associated with a substantially shortened work life, an effect not due to demographic and work characteristics.

OBJECTIVES

We investigated associations between perceived neighborhood problems and quality of life (QOL), physical functioning, and depressive symptoms among adults with asthma.

METHODS

Using cross-sectional data from adults with asthma in northern California (n=435), we examined associations between 5 types of perceived neighborhood problems (traffic, noise, trash, smells, and fires) and asthma-specific QOL (Marks instrument), physical functioning (Short Form-12 physical component summary), and depressive symptoms (Center for Epidemiological Studies-Depression). We used multivariate regression analysis.

RESULTS

When asthma severity and sociodemographics were taken into account, people reporting a score of 8 or higher on a scale of 0 to 25 for serious problems (the top quartile of seriousness) in their neighborhoods had significantly poorer QOL scores (mean difference=5.91; standard error [SE]=1.63), poorer physical functioning (mean difference=-3.04; SE=1.27), and almost a fivefold increase in depressive symptoms (odds ratio=4.79; 95% confidence interval=2.41, 9.52).

CONCLUSIONS

A high level of perceived neighborhood problems was associated with poorer QOL, poorer physical functioning, and increased depressive symptoms among people with asthma when disease severity and sociodemographic factors were taken into account.

BACKGROUND

The Airways Questionnaire 20 (AQ20) is a concise measure of health-related quality of life (HRQL) in obstructive airway disease; however, its original format may underestimate impairment due to the complete cessation of certain activities.

METHODS

We revised seven items of the original AQ20 (revised AQ20 [AQ20-R]), adding response options for inability to perform certain activities. We assessed the performance of the AQ20-R among 352 adults with various airway conditions identified through a random telephone sample. Concurrent validity of the AQ20-R was assessed relative to the Short Form-12 (SF-12) physical component summary (PCS), FEV(1), and medication use. Predictive validity was assessed relative to health-care utilization among 278 subjects studied longitudinally.

RESULTS

Twenty-one of 352 subjects were unable to perform at least one activity. These subjects demonstrated higher AQ20-R scores (p < 0.001) indicating worse HRQL. Mean (+/- SD) AQ20-R scores differed significantly (p < 0.001) among subjects with COPD (8.9 +/- 5.2), asthma (6.7 +/- 5.0), and chronic bronchitis (4.7 +/- 4.2). At baseline, the AQ20-R correlated with the SF-12 PCS (r = - 0.55, p < 0.001) and FEV(1) (r = - 0.43, p < 0.001), and was associated with the use of respiratory-specific therapies (p

CONCLUSIONS

The AQ20-R is a valid respiratory-specific HRQL measure that accounts for activity cessation among the most impaired and can be used across various airway conditions.

BACKGROUND

Although personal cigarette smoking is the most important cause and modulator of chronic obstructive pulmonary disease (COPD), secondhand smoke (SHS) exposure could influence the course of the disease. Despite the importance of this question, the impact of SHS exposure on COPD health outcomes remains unknown.

METHODS

We used data from two waves of a population-based multiwave U.S. cohort study of adults with COPD. 77 non-smoking respondents with a diagnosis of COPD completed direct SHS monitoring based on urine cotinine and a personal badge that measures nicotine. We evaluated the longitudinal impact of SHS exposure on validated measures of COPD severity, physical health status, quality of life (QOL), and dyspnea measured at one year follow-up.

RESULTS

The highest level of SHS exposure, as measured by urine cotinine, was cross-sectionally associated with poorer COPD severity (mean score increment 4.7 pts; 95% CI 0.6 to 8.9) and dyspnea (1.0 pts; 95% CI 0.4 to 1.7) after controlling for covariates. In longitudinal analysis, the highest level of baseline cotinine was associated with worse COPD severity (4.7 points; 95% CI -0.1 to 9.4; p = 0.054), disease-specific QOL (2.9 pts; -0.16 to 5.9; p = 0.063), and dyspnea (0.9 pts; 95% CI 0.2 to 1.6 pts; p < 0.05), although the confidence intervals did not always exclude the no effect level.

CONCLUSION

Directly measured SHS exposure appears to adversely influence health outcomes in COPD, independent of personal smoking. Because SHS is a modifiable risk factor, clinicians should assess SHS exposure in their patients and counsel its avoidance. In public health terms, the effects of SHS exposure on this vulnerable subpopulation provide a further rationale for laws prohibiting public smoking.

The aim of the present study was to predict which patients with severe or difficult-to-treat asthma are at highest risk for healthcare utilisation can be predicted so as to optimise clinical management. Data were derived from 2,821 adults with asthma enrolled in The Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens (TENOR) study. Multiple potential predictors were assessed at baseline using a systematic algorithm employing stepwise logistic regression. Outcomes were asthma-related hospitalisations or emergency department (ED) visits within 6 months following baseline. Overall, 239 subjects (8.5%) reported hospitalisation or ED visits at follow-up. Predictors retained after multivariate analysis were as follows: younger age; female sex; non-white race; body mass index > or =35 kg x m(-2); post-bronchodilator per cent predicted forced vital capacity <70%; history of pneumonia; diabetes; cataracts; intubation for asthma; and three or more steroid bursts in the prior 3 months. A final risk score derived from the logistic regression model ranged from 0-18 and was highly predictive (c-index: 0.78) of hospitalisation or ED visits. This tool was re-tested in a prospective validation using outcomes at 12- to 18-months follow-up among the same cohort (c-index: 0.77). The risk score derived is a clinically useful tool for assessing the likelihood of asthma-related hospitalisation or emergency department visits in adults with severe and difficult-to-treat asthma.

BACKGROUND

The relationship between stress and quality of life in adults with asthma has not been well studied. Stress, quantified by negative life events, may be linked to quality of life in asthma through multiple pathways, including increase in disease severity and adverse effects on socioeconomic status (SES).

METHODS

The responses to a self-completed questionnaire assessing negative life events (NLEs) in the previous 12 months (from a 24-item checklist) among 189 adults with asthma from a well-characterised cohort were analysed. The relationship between the number of NLEs reported and asthma-specific quality of life (AQOL) was measured with the Marks instrument. General linear modelling was used to test the conjoint effects of NLEs, SES and disease severity based on the Severity of Asthma Score, a validated acute and chronic disease measure.

RESULTS

Those with annual family incomes < 60,000 dollars reported significantly more NLEs than those with higher incomes (p = 0.03). The number of NLEs did not differ significantly between those with forced expiratory volume in 1 s <80% predicted and those with >80% predicted, nor among those with lower compared with higher Severity of Asthma Score. The frequency of NLEs was associated with poorer (higher numerical score) AQOL (p = 0.002). When studied together in the same model, combinations of income level and asthma severity (greater or lesser Severity of Asthma Score; p < 0.001) and number of NLEs (p = 0.03) were both significantly associated with AQOL.

CONCLUSION

NLEs are associated with quality of life among adults with asthma, especially among those of lower SES. Clinicians should be aware of this relationship, especially in vulnerable patient subsets.

PURPOSE

We aimed to elucidate the prevalence of and risk factors for work disability in severe adult asthma and to evaluate the impact of work disability on downstream health outcomes.

METHODS

We used data from a prospective cohort study of 465 adults with severe asthma. Structured telephone interviews ascertained asthma status and employment history. A job exposure matrix (JEM) was used to characterize the likelihood of workplace exposure to "asthmagens."

RESULTS

The prevalence of asthma-related complete work disability was 14% among working-age adults with severe asthma (95% confidence interval, 11%-18%). Among those who were currently employed, the prevalence of partial work disability was 38% (95% confidence interval, 31%-45%). Sociodemographic (P = .027) and medical factors (P = .020) were related to the risk of complete work disability. Both sociodemographic characteristics (P = .06) and work exposures based on the JEM (P = .012) were related to partial work disability. In additional models, poorer asthma severity, physical health status, and mental health status were all associated with a higher risk of complete and partial work disability.

CONCLUSIONS

Work disability is common among adults with severe asthma. There are three sets of risk factors for work disability that are potentially modifiable: smoking, workplace exposures, and asthma severity.