A longitudinal study of adult-onset asthma incidence among HMO members

BACKGROUND: HMO databases offer an opportunity for community based epidemiologic studies of asthma incidence, etiology and treatment. The incidence of asthma in HMO populations and the utility of HMO data, including use of computerized algorithms and manual review of medical charts for determining etiologic factors has not been fully explored. METHODS: We identified adult-onset asthma, using computerized record searches in a New England HMO. Monthly, our software applied exclusion and inclusion criteria to identify an "at-risk" population and "potential cases". Electronic and paper medical records from the past year were then reviewed for each potential case. Persons with other respiratory diseases or insignificant treatment for asthma were excluded. Confirmed adult-onset asthma (AOA) cases were defined as those potential cases with either new-onset asthma or reactivated mild intermittent asthma that had been quiescent for at least one year. We validated the methods by reviewing charts of selected subjects rejected by the algorithm. RESULTS: The algorithm was 93 to 99.3% sensitive and 99.6% specific. Sixty-three percent (n = 469) of potential cases were confirmed as AOA. Two thirds of confirmed cases were women with an average age of 34.8 (SD 11.8), and 45% had no evidence of previous asthma diagnosis. The annualized monthly rate of AOA ranged from 4.1 to 11.4 per 1000 at-risk members. Physicians most commonly attribute asthma to infection (59%) and allergy (14%). New-onset cases were more likely attributed to infection, while reactivated cases were more associated with allergies. Medical charts included a discussion of work exposures in relation to asthma in only 32 (7%) cases. Twenty-three of these (72%) indicated there was an association between asthma and workplace exposures for an overall rate of work-related asthma of 4.9%. CONCLUSION: Computerized HMO records can be successfully used to identify AOA. Manual review of these records is important to confirm case status and is useful in evaluation of provider consideration of etiologies. We demonstrated that clinicians attribute most AOA to infection and tend to ignore the contribution of environmental and occupational exposures

Greater risk of incident asthma cases in adults with Allergic Rhinitis and Effect of Allergen Immunotherapy: A Retrospective Cohort Study

Asthma and rhinitis are often co-morbid conditions. As rhinitis often precedes asthma it is possible that effective treatment of allergic rhinitis may reduce asthma progression. The aim of our study is to investigate history of allergic rhinitis as a risk factor for asthma and the potential effect of allergen immunotherapy in attenuating the incidence of asthma. Hospital-referred non-asthmatic adults, aged 18–40 years between 1990 and 1991, were retrospectively followed up until January and April 2000. At the end of follow up, available subjects were clinically examined for asthma diagnosis and history of allergen specific immunotherapy, second-hand smoking and the presence of pets in the household. A total of 436 non-asthmatic adults (332 subjects with allergic rhinitis and 104 with no allergic rhinitis nor history of atopy) were available for final analyses. The highest OR (odds ratio) associated with a diagnosis of asthma at the end of follow-up was for the diagnosis of allergic rhinitis at baseline (OR, 7.8; 95%CI, 3.1–20.0 in the model containing the covariates of rhinitis diagnosis, sex, second-hand smoke exposure, presence of pets at home, family history of allergic disorders, sensitization to Parietaria judaica; grass pollen; house dust mites; Olea europea: orchard; perennial rye; and cat allergens). Female sex, sensitization to Parietaria judaica and the presence of pets in the home were also significantly predictive of new onset asthma in the same model. Treatment with allergen immunotherapy was significantly and inversely related to the development of new onset asthma (OR, 0.53; 95%CI, 0.32–0.86). In the present study we found that allergic rhinitis is an important independent risk factor for asthma. Moreover, treatment with allergen immunotherapy lowers the risk of the development of new asthma cases in adults with allergic rhinitis

Higher body mass index may induce asthma among adolescents with pre-asthmatic symptoms: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Limited studies have prospectively examined the role of body mass index (BMI) as a major risk factor for asthma during adolescence. This study investigates whether BMI is associated with increased risk of developing physician-diagnosed asthma during 12-month follow-up among adolescents with undiagnosed asthma-like symptoms at baseline.</p> <p>Methods</p> <p>A total of 4,052 adolescents with undiagnosed asthma-like symptoms at baseline were re-examined after a 12-month follow-up. Asthma cases were considered confirmed only after diagnosis by a physician based on the New England core and International Study of Asthma and Allergies in Childhood (ISAAC) criteria video questionnaires, and accompanying pulmonary function tests. Logistic regression analyses were used to evaluate the relationship of BMI and the risk of acquiring asthma.</p> <p>Results</p> <p>The results indicated that girls with higher BMI were at an increased risk of developing asthma during the 12-month follow-up. The odds ratios for girls developing physician-diagnosed asthma were 1.75 (95% CI = 1.18-2.61) and 1.12 (95% CI = 0.76-1.67), respectively, for overweight and obesity as compared to the normal weight reference group after adjustment for other covariates. A similar relationship was not observed for overweight and obese boys who were also significantly more active than their female counterparts.</p> <p>Conclusions</p> <p>Increased BMI exaggerates the risk of acquiring asthma in symptomatic adolescent females but not in adolescent males. Thus, gender is an important modifier of BMI-related asthma risk. Additional research will be required to determine whether the increased asthma risk results from genetic, physiological or behavioural differences.</p

Characterization of regulatory T cells in urban newborns

© 2009 Ly et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Long-Term Exposure to Ambient Air Pollution and Mortality Due to Cardiovascular Disease and Cerebrovascular Disease in Shenyang, China

BACKGROUND: The relationship between ambient air pollution exposure and mortality of cardiovascular and cerebrovascular diseases in human is controversial, and there is little information about how exposures to ambient air pollution contribution to the mortality of cardiovascular and cerebrovascular diseases among Chinese. The aim of the present study was to examine whether exposure to ambient-air pollution increases the risk for cardiovascular and cerebrovascular disease. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a retrospective cohort study among humans to examine the association between compound-air pollutants [particulate matter <10 µm in aerodynamic diameter (PM(10)), sulfur dioxide (SO(2)) and nitrogen dioxide (NO(2))] and mortality in Shenyang, China, using 12 years of data (1998-2009). Also, stratified analysis by sex, age, education, and income was conducted for cardiovascular and cerebrovascular mortality. The results showed that an increase of 10 µg/m(3) in a year average concentration of PM(10) corresponds to 55% increase in the risk of a death cardiovascular disease (hazard ratio [HR], 1.55; 95% confidence interval [CI], 1.51 to 1.60) and 49% increase in cerebrovascular disease (HR, 1.49; 95% CI, 1.45 to 1.53), respectively. The corresponding figures of adjusted HR (95%CI) for a 10 µg/m(3) increase in NO(2) was 2.46 (2.31 to 2.63) for cardiovascular mortality and 2.44 (2.27 to 2.62) for cerebrovascular mortality, respectively. The effects of air pollution were more evident in female that in male, and nonsmokers and residents with BMI<18.5 were more vulnerable to outdoor air pollution. CONCLUSION/SIGNIFICANCE: Long-term exposure to ambient air pollution is associated with the death of cardiovascular and cerebrovascular diseases among Chinese populations

Inhaled corticosteroids in childhood asthma: the story continues

Inhaled corticosteroids (ICS) are the most effective anti-inflammatory drugs for the treatment of persistent asthma in children. Treatment with ICS decreases asthma mortality and morbidity, reduces symptoms, improves lung function, reduces bronchial hyperresponsiveness and reduces the number of exacerbations. The efficacy of ICS in preschool wheezing is controversial. A recent task force from the European Respiratory Society on preschool wheeze defined two different phenotypes: episodic viral wheeze, wheeze that occurs only during respiratory viral infections, and multiple-trigger wheeze, where wheeze also occurs in between viral episodes. Treatment with ICS appears to be more efficacious in the latter phenotype. Small particle ICS may offer a potential benefit in preschool children because of the favourable spray characteristics. However, the efficacy of small particle ICS in preschool children has not yet been evaluated in prospective clinical trials. The use of ICS in school children with asthma is safe with regard to systemic side effects on the hypothalamic–pituitary–adrenal axis, growth and bone metabolism, when used in low to medium doses. Although safety data in wheezing preschoolers is limited, the data are reassuring. Also for this age group, adverse events tend to be minimal when the ICS is used in appropriate doses