Acknowledgement and corrections for flawed data.
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Asthma↗
Biomedical subjects
P D Blanc
Publications and source records attributed to P D Blanc.
The work impact of asthma and rhinitis: findings from a population-based survey.
Asthma and rhinitis are common chronic conditions that affect adults of working age. Little is known about their relative impacts on work loss and decreased productivity. Using random digit telephone dialing, we carried out a population-survey of adults in Northern California aged 18-50 years. We interviewed 125 persons with asthma (with or without concomitant rhinitis) and 175 persons with rhinitis alone. Study eligibility was based on subject report of a physician's diagnosis of asthma and/or a rhinitis-related condition. Any adult labor force participation since condition onset was lower among those with asthma (88%) than among those with rhinitis alone (97%) (P = 0.002). In contrast, among those still employed, decreased job effectiveness was more frequently reported in the rhinitis group (43 of 121; 36%) compared to those with asthma (14 of 72; 19%) (P = 0.02). Condition-attributed lost work was common in both groups, with more than 20% reporting one or more complete or partial work days lost in the 4 weeks previous to interview. Taking into account age, gender, race, and smoking status, those with asthma were more likely to have no labor force participation after diagnosis (OR = 3.0; 95% CI 1.1-7.7) and less likely to report decreased job effectiveness among those remaining employed (OR = 0.4; 95% CI 0.2-0.9). Excluding subjects from the rhinitis group most likely to have unreported asthma based on past medication use had little impact on these associations. Both asthma and rhinitis negatively affect work productivity. Those with asthma are less likely to be employed at all, while among those remaining on the job, rhinitis is a more potent cause of decreased work effectiveness. The economic impact of asthma and rhinitis and related conditions may be under-appreciated.
Absenteeism↗
Beta agonists, inhaled steroids, and the risk of intensive care unit admission for asthma.
Although inhaled corticosteroid (ICS) use is associated with a decreased risk of hospitalization for asthma, the impact of ICS on the risk of life-threatening asthma exacerbation is less clear. The effect of ICS and inhaled beta agonist (IBA) dispensing on the risk of intensive care unit admission for asthma, a surrogate for life-threatening exacerbation, is evaluated. Using computerized International classification of diseases (ICD)-9 discharge diagnoses, a cohort of all 2,344 adult Northern California members of a health maintenance organization hospitalized for asthma over a 2-yr period were identified. Computerized pharmacy data was used to ascertain asthma medications dispensed during the 3-,6-, and 12-month intervals preceding index hospitalization for asthma. During the 3-months preceding hospitalization, a minority of subjects had no IBA units dispensed (34%), with 14% receiving low level (1 unit), 20% medium level (2-3 units), and 32% high level (> or = 4 units) therapy. A substantial proportion received no ICS units (55%), whereas 13% had low, 16% medium, and 15% high level therapy. In multiple logistic regression analysis, high level IBA use was associated with a greater risk of intensive care unit (ICU) admission for asthma after controlling for asthma severity. There was no relationship, however, between low or medium level IBA use and ICU admission. Conversely, medium level and high level ICS use were associated with a reduced risk of ICU admission. Analysing 6- and 12-month medication dispensing data, similar risk patterns were observed. Inhaled corticosteroid dispensing was associated with reduced risk of intensive care unit admission among adults hospitalized for asthma, whereas the opposite applied for high dose beta agonist usage. This suggests that ICS prescription to adults with moderate-to-severe asthma could reduce the risk of life-threatening exacerbation.
Administration, Inhalation↗
Measurement of environmental tobacco smoke exposure among adults with asthma.
Because the morbidity and mortality from adult asthma have been increasing, the identification of modifiable environmental exposures that exacerbate asthma has become a priority. Limited evidence suggests that exposure to environmental tobacco smoke (ETS) may adversely affect adults with asthma. To study the effects of ETS better, we developed a survey instrument to measure ETS exposure in a cohort of adults with asthma living in northern California, where public indoor smoking is limited. To validate this survey instrument, we used a passive badge monitor that measures actual exposure to ambient nicotine, a direct and specific measure of ETS. In this validation study, we recruited 50 subjects from an ongoing longitudinal asthma cohort study who had a positive screening question for ETS exposure or potential exposure. Each subject wore a passive nicotine badge monitor for 7 days. After the personal monitoring period, we readministered the ETS exposure survey instrument. Based on the survey, self-reported total ETS exposure duration ranged from 0 to 70 hr during the previous 7 days. Based on the upper-range boundary, bars or nightclubs (55 hr) and the home (50 hr) were the sites associated with greatest maximal self-reported exposure. As measured by the personal nicotine badge monitors, the overall median 7-day nicotine concentration was 0.03 microg/m(3) (25th-75th interquartile range 0-3.69 microg/m(3)). Measured nicotine concentrations were highest among persons who reported home exposure (median 0.61 microg/m(3)), followed by work exposure (0.03 microg/m(3)), other (outdoor) exposure (0.025 microg/m(3)), and no exposure (0 microg/m(3); p = 0.03). The Spearman rank correlation coefficient between self-reported ETS exposure duration and directly measured personal nicotine concentration during the same 7-day period was 0.47, supporting the survey's validity (p = 0.0006). Compared to persons with no measured exposure, lower-level [odds ratio (OR) 1.9; 95% confidence interval (CI), 0.4-8.8] and higher-level ETS exposures (OR 6.8; 95% CI, 1.4-32.3) were associated with increased risk of respiratory symptoms. A brief, validated survey instrument can be used to assess ETS exposure among adults with asthma, even with low levels of exposure. This instrument could be a valuable tool for studying the effect of ETS exposure on adult asthma health outcomes.
Adult↗
Risk factors for hospitalization among adults with asthma: the influence of sociodemographic factors and asthma severity.
BACKGROUND: The morbidity and mortality from asthma have markedly increased since the late 1970s. The hospitalization rate, an important marker of asthma severity, remains substantial. METHODS: In adults with health care access, we prospectively studied 242 with asthma, aged 18-50 years, recruited from a random sample of allergy and pulmonary physician practices in Northern California to identify risk factors for subsequent hospitalization. RESULTS: Thirty-nine subjects (16%) reported hospitalization for asthma during the 18-month follow-up period. On controlling for asthma severity in multiple logistic regression analysis, non-white race (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.1-8.8) and lower income (OR, 1.1 per $10,000 decrement; 95% CI, 0.9-1.3) were associated with a higher risk of asthma hospitalization. The severity-of-asthma score (OR, 3.4 per 5 points; 95%, CI 1.7-6.8) and recent asthma hospitalization (OR, 8.3; 95%, CI, 2.1-33.4) were also related to higher risk, after adjusting for demographic characteristics. Reliance on emergency department services for urgent asthma care was also associated with a greater likelihood of hospitalization (OR, 3.2; 95% CI, 1.0-9.8). In multivariate analysis not controlling for asthma severity, low income was even more strongly related to hospitalization (OR, 1.2 per $10,000 decrement; 95% CI, 1.02-1.4). CONCLUSION: In adult asthmatics with access to health care, non-white race, low income, and greater asthma severity were associated with a higher risk of hospitalization. Targeted interventions applied to high-risk asthma patients may reduce asthma morbidity and mortality.
Adult↗
Elevated liver enzymes in asymptomatic patients.
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Chemical and Drug Induced Liver Injury↗
Asthma on the job: work-related factors in new-onset asthma and in exacerbations of pre-existing asthma.
Occupational asthma (OA) can be defined as variable airways narrowing causally related to exposure in the working environment to airborne dusts, gases, vapours or fumes. There are many agents in the work-place that can induce asthma or cause substantial deterioration in pre-existing asthma. It has been estimated that 5-15% of adult-onset asthma can be attributed to occupational exposures. Hence adult patients, especially those with new-onset asthma, must be investigated with regard to occupational risk factors for disease. The prognosis for OA is improved if the causal exposure is controlled either by controlling the exposure at the workplace or by moving the patient out of the workplace.
Acrylates↗
Reanalysis of Blanc PD et al, "Use of herbal products, coffee or black tea, and over-the-counter medications as self treatments among adults with asthma".
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Adolescent↗
Predictors of cigarette smoking and smoking cessation among adults with asthma.
OBJECTIVES: This study sought to determine the predictors of smoking and time until smoking cessation in a cohort of adults with asthma. METHODS: Adults with asthma (n = 374) in northern California completed structured telephone interviews at baseline and 18-month follow-up. RESULTS: Of the 374 subjects, 156 reported ever having smoked, and 39 indicated that they currently smoked. Earlier birth cohort, lower educational attainment. White race, and presence in childhood residence of an adult who smoked were associated with a greater risk of ever smoking. Lower educational attainment, early smoking initiation, higher daily cigarette consumption, and late-childhood-onset asthma were associated with a longer interval until smoking cessation. CONCLUSIONS: Persons with asthma at high risk of cigarette smoking and delayed quitting can be identified on the basis of clinical and demographic characteristics.
Adult↗
Work dynamics of adults with asthma.
BACKGROUND: Asthma has been found to be among the most common conditions in the working age population and is among the most common causes of work limitation, but we could find no longitudinal studies of employment among persons with this condition. METHODS: A panel of 601 persons with a diagnosis of asthma from random samples of northern California pulmonologists and allergy-immunologists were interviewed as many as three times at 18-month intervals by a trained survey worker to report on the severity of disease, demographic characteristics, and the extent of their employment. Their employment was then compared to that of a matched sample from the U.S. Bureau of the Census Current Population Survey. RESULTS: Ninety-two percent of the persons with asthma had worked at some point prior to study enrollment. Among persons with onset during adulthood, only 29% of those who were not employed at disease onset were working at study enrollment, compared to 68% among those who were employed. Among the 420 persons interviewed three times, 75, 81, and 75%, respectively, were employed as of the three interviews. Among these 420, 66% were continuously employed and 15% were continuously not employed. The principal determinants of continuity of employment were demographic and employment characteristics, not medical ones. The employment rate and hours of work per week and per year of the persons with asthma were similar to the matched sample. CONCLUSIONS: Asthma has not substantially impeded the employment of the persons with asthma we studied, with the exception that those who were not employed at disease onset continued to have low employment rates.
Adolescent↗
The legacy of war gas.
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Airway Obstruction↗
How much adult asthma can be attributed to occupational factors?
PURPOSE: Many occupational factors can cause asthma or reactivate preexisting disease. We carried out a critical review and synthesis of the available literature to estimate the proportion of adult asthma that is attributable to workplace factors. METHODS: We reviewed published citations from 1966 through May 1999 as well as recent abstracts of studies providing risk estimates for asthma among various occupations. We extracted published attributable risk estimates, derived others from published data, and extrapolated estimates from the incidence rates of occupational asthma. We used a semiquantitative score to rank studies based on their characteristics. RESULTS: We obtained 43 attributable risk estimates from 19 different countries: 23 were published estimates, 8 were derived from published data, and 12 were extrapolated from incidence data. The median value for the attributable risk of occupationally associated asthma was 9%(25th to 75th interquartile range: 5% to 19%). The derived estimates (median attributable risk = 25%) were significantly greater than published values (median = 9%, P = 0.002), whereas the extrapolated estimates were significantly lower (median = 5%, P = 0.04). The 12 highest scored studies based on their characteristics yielded a median risk estimate of 15%. CONCLUSION: Occupational factors are associated with about 1 in 10 cases of adult asthma, including new onset disease and reactivation of preexisting asthma.
Adult↗
The Marks Asthma Quality of Life Questionnaire: further validation and examination of responsiveness to change.
We performed analyses to examine the structure, validity, and responsiveness to change of the Marks Asthma Quality of Life Questionnaire (AQLQ), originally validated in Australia in a self-administered format, among 539 U.S. subjects with asthma. Subjects were interviewed twice by telephone over an 18-month period. Based on factor analyses, the subscale structure of the AQLQ was modified slightly to eliminate item overlap among subscale scores. Cross-sectionally, total AQLQ scores were significantly correlated in expected directions with baseline asthma severity scores (r = 0.58), SF-36 physical (r = -0.66) and mental (r = -0.40) health status scores, and pulmonary function (FEV1% predicted, r = -0.14). Longitudinally, changes in AQLQ total and subscale scores were significantly (P<0.01) associated with changes in asthma severity and both physical and mental status. The AQLQ, administered by telephone, appears to be useful for assessing changes in the impact of adult asthma.
Adult↗
Measurement of fibroblast proliferative activity in bronchoalveolar lavage fluid in the analysis of obliterative bronchiolitis among lung transplant recipients.
BACKGROUND: Bronchiolitis obliterans occurs in 30% to 80% of lung-transplant recipients and is a direct cause of death in more than 40% of patients with this complication. This study assessed the potential utility of measuring fibroblast-proliferative activity in bronchoalveolar lavage fluid from lung-transplant recipients to better understand the pathogenesis of this process. METHODS: The capacity of bronchoalveolar lavage fluid obtained from transplant recipients, during routine surveillance bronchoscopy, to stimulate the proliferation of human lung fibroblasts in vitro was assessed retrospectively and compared to that of control subjects. For each recipient, a correlation was made between the fibroblast-proliferative activity in serial lavage samples over time and the other modalities employed for detecting post-transplant complications including spirometry, transbronchial lung biopsy, and high-resolution computed tomography. RESULTS: There was a significant difference in fibroblast-proliferative activity between volunteer and transplant recipient groups (p = 0.002). Further, for each transplant recipient, the decline in the forced expired flow rate between 25% and 75% of expired volume (FEF(25%-75%)) was correlated with the mean fibroblast-proliferative activity during the period of this study (r = 0.83; p = 0.04). CONCLUSIONS: A sustained increase in fibroblast-proliferative activity in lavage supernatant precedes both histologic and physiologic evidence of bronchiolitis obliterans. Relative to an increase in fibroblast-proliferative activity or abnormalities in FEF25%-75%, a decrease in forced expiratory volume in 1 second is a late finding.
Biopsy↗
Asthma-related work disability in Sweden. The impact of workplace exposures.
Work disability due to respiratory disease, especially asthma, is common and costly among working age adults. The goal of this analysis was to characterize the risk factors for such disability. We analyzed data from the Swedish part of the European Community Respiratory Health Survey (ECRHS), a random population-based sample of adults age 20 to 44, enriched with symptomatic subjects at increased likelihood of having asthma. We analyzed structured interview data available for 2,065 subjects and further analyzed methacholine challenge and skin prick test data for 1,562 of these. We defined respiratory work disability as reported job change or work loss due to breathing affected by a job. We used binary generalized linear modeling with a log link to estimate disability risk. Eighty-four subjects (4%) reported such work disability. This increased to 13% among those with asthma (45 of 350 subjects). Adjusting for covariates, occupations at high risk for asthma were associated with disability (prevalence ratio [PR] 1.8; 95% confidence interval [CI] 1.1 to 3.0), as was self-reported regular exposure to environmental tobacco smoke (ETS) at work (PR 1.8; 95% CI 1.1 to 3.1) and self- reported job exposure to vapors, gases, dust, or fumes (VGDF) (PR 4.3; 95% CI 2.2 to 8.6). Workplace ETS exposure was also associated with methacholine challenge-positive asthma reported to be symptomatic at work among male subjects (PR 4. 2; 95% CI 1.8 to 9.8), whereas high asthma-risk occupations were associated with this outcome among female subjects (PR 2.7; 95% CI 1. 05 to 7.1). Respiratory work disability, defined as breathing-related job change due to work loss, was associated with workplace exposures themselves, even after taking into account other covariates. Better control of workplace exposures, including workplace ETS, may reduce work disability caused by respiratory conditions, especially adult asthma.
Adult↗
Persistent increases of BAL neutrophils as a predictor of mortality following lung transplant.
STUDY OBJECTIVES: To evaluate whether findings from surveillance bronchoscopy predict survival following lung transplantation. DESIGN: Retrospective review and analysis of 498 bronchoscopies with transbronchial biopsy (TBB) and BAL performed in 34 patients after lung transplantation. SETTING: University-based, tertiary referral medical center. PATIENTS: Thirty-four patients after lung transplantation. The mean age at transplantation was 49+/-9 years; 20 (59%) were female. Twenty-four (71%) underwent single and 10 (29%) underwent bilateral lung transplantation. The most common pretransplantation diagnostic groups were emphysema/COPD without concomitant alpha1-antiprotease deficiency (n = 13) and other obstructive disease processes (n = 10). INTERVENTIONS: Over follow-up, subjects underwent multiple bronchoscopies with TBB and BAL. The median number per subject was 15 (25 to 75% range 13 to 17). MEASUREMENTS AND RESULTS: We calculated the overall median BAL WBCs and median percent neutrophils (polymorphonuclear leukocytes [PMNs]) among all of the BALs performed for each subject. We then calculated the mean +/- SD of those median values. We used Cox proportionate hazards to assess mortality risk. The median overall follow-up observation period for the cohort was 560 days. There were 11 deaths during this period. Twenty-four subjects (71%) had acute rejection (AR) grades 2 to 4 (mild to severe), and nine (27%) had obliterative bronchiolitis (OB) diagnosed by TBB at any point. The mean value for BAL WBCs was 366+/-145 x 10(3) per milliliter; for percentage PMNs, the mean was 7+/-10%. Adjusting for age, gender, single vs bilateral lung transplantation, pretransplantation diagnostic group, presence of AR, presence of OB, BAL WBC concentration, and lymphocyte CD4/CD8 ratio, PMN percent was a significant predictor of mortality (p = 0.02). CONCLUSIONS: Ongoing inflammation manifested by an increased percentage PMNs over repeated bronchoscopies predicts mortality following lung transplantation. Biopsy data alone may be insufficient to identify posttransplantation patients at risk of poor outcome.
Adult↗