Differential effects of outdoor versus indoor fungal spores on asthma morbidity in inner-city children.

BACKGROUND: Although sensitization to fungal allergens is prevalent in inner-city children with asthma, the relationship between fungal exposure and morbidity is poorly understood. OBJECTIVE: We examined relationships between fungal sensitization, exposure, and asthma morbidity in inner-city children. METHODS: Participants were 5 to 11 years old and enrolled in the Inner-City Asthma Study. This report includes the subset of children with at least 1 positive skin test (PST) response to a fungal allergen extract; for these children, indoor and outdoor airborne culturable fungi levels were measured at baseline and throughout the 2-year study. Asthma morbidity measures were collected prospectively. The primary outcome was symptom days per 2 weeks. RESULTS: At baseline, children with a PST response to a fungal allergen extract had significantly more symptom days compared with those without a PST response to any fungal allergen extract (6.3 vs 5.7 days per 2 weeks, P = .04). During the study, increases in total fungal exposure and indoor Penicillium species exposure were associated with increases in symptom days and asthma-related unscheduled visits. Indoor exposures to total fungi and to Penicillium species were associated with significant increases in unscheduled visits, even after controlling for outdoor fungal levels. Adverse effects associated with exposure to a specific fungus were stronger among children with PST responses to that fungal allergen extract compared with those seen in children with negative skin test responses. CONCLUSION: Outdoor fungal exposure is primarily associated with increased asthma symptoms and increased risk of exacerbations in this population.

Retention strategies and predictors of attrition in an urban pediatric asthma study.

BACKGROUND: The Urban Environment and Childhood Asthma (URECA) study is a multicenter prospective birth cohort study designed to examine factors related to the development of childhood asthma and allergies in an inner-city population. The retention of these participants has been challenging due to high mobility, inconsistent phone service, custody issues, and stressful life situations. PURPOSE: In this article, we describe the specific retention challenges we encountered during the first 2 years of follow-up in URECA and the strategies we utilized to address them. We also examine how selected maternal characteristics and other factors are related to retention and missed study visits. METHODS: Strategies implemented to engage participants included: collecting updated and alternative contact information, after-hours phone calls to participants, culturally competent staff, flexible study event scheduling, clinic visit transportation, quarterly newsletters, retention events, drop-in home visits, and cell phone reimbursements. An internally developed web-based data management system enabled close monitoring by site teams and the coordinating center. The rate of deactivations was calculated using survival analysis. Characteristics of active and deactivated participants were compared using the chi-squared test with a Cochran-Mantel - Haenszel adjustment for study site. The proportion of missed visits of the total expected in the first 2 years was calculated and compared by family characteristics using an ANOVA model or a trend test controlling for study site. All analyses were performed using SAS version 9.1 (Cary, NC). RESULTS: The 2-year retention rate was 89%. Participation in the first study event predicted subsequent engagement in study activities. Mothers who did not complete the first visit were more likely to miss future events (46.1% vs. 8.9%, p<0.0001) and to be deactivated (38.5% vs. 4.5%, p<0.0001). Mothers under 18 years of age were more likely to leave the study compared to older mothers (22.7% vs. 10.1%, p = 0.02). Also, mothers who were married missed fewer events than those not married (8.8% vs. 15.6%, p = 0.01). In addition, deactivations were more common when the child had entered daycare by 3 months of age (10.9% vs. 3.6%, p = 0.05). LIMITATIONS: The URECA population is predominantly minority, thus our findings might not be generalizable to other populations. Furthermore, we may not be able to observe the effects that might exist in a more diverse population. For example, 86% of the mothers are unmarried, making it difficult to reliably examine the effect of marital status. CONCLUSION: In research, successfully engaging and retaining participants is essential for achieving the study objectives. Identifying factors related to missed visits and deactivations are the initial step in recognizing the potential at-risk participants and can enable the design of targeted strategies to retain participants.

Asthma morbidity among inner-city adolescents receiving guidelines-based therapy: role of predictors in the setting of high adherence.

BACKGROUND: With the expanding effort to provide guidelines-based therapy to adolescents with asthma, attention must be directed to evaluating which factors predict future asthma control when guidelines-based management is applied. OBJECTIVE: We evaluated the role of fraction of exhaled nitric oxide in parts per billion, markers of allergic sensitization, airway inflammation, and measures of asthma severity in determining future risk of asthma symptoms and exacerbations in adolescents and young adults participating in the Asthma Control Evaluation study. METHODS: Five hundred forty-six inner-city residents, ages 12 through 20 years, with persistent asthma were extensively evaluated at study entry for predictors of future symptoms and exacerbations over the subsequent 46 weeks, during which guidelines-based, optimal asthma management was offered. Baseline measurements included fraction of exhaled nitric oxide in parts per billion, total IgE, allergen-specific IgE, allergen skin test reactivity, asthma symptoms, lung function, peripheral blood eosinophils, and, for a subset, airway hyperresponsiveness and sputum eosinophils. RESULTS: The baseline characteristics we examined accounted for only a small portion of the variance for future maximum symptom days and exacerbations--11.4% and 12.6%, respectively. Future exacerbations were somewhat predicted by asthma symptoms, albuterol use, previous exacerbations, and lung function, whereas maximum symptom days were predicted, also to a modest extent, by symptoms, albuterol use, and previous exacerbations, but not lung function. CONCLUSION: Our findings demonstrate that the usual predictors of future disease activity have little predictive power when applied to a highly adherent population with persistent asthma that is receiving guidelines-based care. Thus, new predictors need to be identified that will be able to measure the continued fluctuation of disease that persists in highly adherent, well-treated populations such as the one studied.

Results of a home-based environmental intervention among urban children with asthma.

BACKGROUND: Children with asthma who live in the inner city are exposed to multiple indoor allergens and environmental tobacco smoke in their homes. Reductions in these triggers of asthma have been difficult to achieve and have seldom been associated with decreased morbidity from asthma. The objective of this study was to determine whether an environmental intervention tailored to each child's allergic sensitization and environmental risk factors could improve asthma-related outcomes. METHODS: We enrolled 937 children with atopic asthma (age, 5 to 11 years) in seven major U.S. cities in a randomized, controlled trial of an environmental intervention that lasted one year (intervention year) and included education and remediation for exposure to both allergens and environmental tobacco smoke. Home environmental exposures were assessed every six months, and asthma-related complications were assessed every two months during the intervention and for one year after the intervention. RESULTS: For every 2-week period, the intervention group had fewer days with symptoms than did the control group both during the intervention year (3.39 vs. 4.20 days, P<0.001) and the year afterward (2.62 vs. 3.21 days, P<0.001), as well as greater declines in the levels of allergens at home, such as Dermatophagoides farinae (Der f1) allergen in the bed (P<0.001) and on the bedroom floor (P=0.004), D. pteronyssinus in the bed (P=0.007), and cockroach allergen on the bedroom floor (P<0.001). Reductions in the levels of cockroach allergen and dust-mite allergen (Der f1) on the bedroom floor were significantly correlated with reduced complications of asthma (P<0.001). CONCLUSIONS: Among inner-city children with atopic asthma, an individualized, home-based, comprehensive environmental intervention decreases exposure to indoor allergens, including cockroach and dust-mite allergens, resulting in reduced asthma-associated morbidity.

A randomized clinical trial of clinician feedback to improve quality of care for inner-city children with asthma.

CONTEXT: Barriers impede translating recommendations for asthma treatment into practice, particularly in inner cities where asthma morbidity is highest. METHODS: The purpose of this study was to test the effectiveness of timely patient feedback in the form of a letter providing recent patient-specific symptoms, medication, and health service use combined with guideline-based recommendations for changes in therapy on improving the quality of asthma care by inner-city primary care providers and on resultant asthma morbidity. This was a randomized, controlled clinical trial in 5- to 11-year-old children (n = 937) with moderate to severe asthma receiving health care in hospital- and community-based clinics and private practices in 7 inner-city urban areas. The caretaker of each child received a bimonthly telephone call to collect clinical information about the child's asthma. For a full year, the providers of intervention group children received bimonthly computer-generated letters based on these calls summarizing the child's asthma symptoms, health service use, and medication use with a corresponding recommendation to step up or step down medications. We measured the number and proportion of scheduled visits resulting in stepping up of medications, asthma symptoms (2-week recall), and health care use (2-month recall). RESULTS: In this population, only a modest proportion of children whose symptoms warranted a medication increase actually had a scheduled visit to reevaluate their asthma treatment. However, in the 2-month interval after receipt of a step-up letter, 17.1% of the letters were followed by scheduled visits in the intervention group compared with scheduled visits 12.3% of the time by the control children with comparable clinical symptoms. Asthma medications were stepped up when indicated after 46.0% of these visits in the intervention group compared with 35.6% in the control group, and when asthma symptoms warranted a step up in therapy, medication changes occurred earlier among the intervention children. Among children whose medications were stepped up at any time during the 12-month study period, those in the intervention group experienced 22.1% fewer symptom days and 37.9% fewer school days missed. The intention-to-treat analysis showed no difference over the intervention year in the number of symptom days, yet there was a trend toward fewer days of limited activity and a significant decrease in emergency department visits by the intervention group compared with controls. This 24% drop in emergency department visits resulted in an intervention that was cost saving in its first year. CONCLUSIONS: Patient-specific feedback to inner-city providers increased scheduled asthma visits, increased asthma visits in which medications were stepped up when clinically indicated, and reduced emergency department visits.

Inner City Asthma Study: relationships among sensitivity, allergen exposure, and asthma morbidity.

BACKGROUND: Asthma-associated morbidity is rising, especially in inner city children. OBJECTIVE: We evaluated the allergen sensitivities, allergen exposures, and associated morbidity for participants in the Inner City Asthma Study. We also determined geographic variations of indoor allergen levels. METHODS: Nine hundred thirty-seven inner city children 5 to 11 years old with moderate to severe asthma underwent allergen skin testing. Bedroom dust samples were evaluated for Der p 1, Der f 1, Bla g 1, Fel d 1, and Can f 1. RESULTS: Skin test sensitivities to cockroach (69%), dust mites (62%), and molds (50%) predominated, with marked study site-specific differences. Cockroach sensitivity was highest in the Bronx, New York, and Dallas (81.2%, 78.7%, and 78.5%, respectively), and dust mite sensitivity was highest in Dallas and Seattle (83.7% and 78.0%, respectively). A majority of homes in Chicago, New York, and the Bronx had cockroach allergen levels greater than 2 U/g, and a majority of those in Dallas and Seattle had dust mite allergen levels greater than 2 microg/g. Levels of both of these allergens were influenced by housing type. Cockroach allergen levels were highest in high-rise apartments, whereas dust mite allergen levels were highest in detached homes. Children who were both sensitive and exposed to cockroach allergen had significantly more asthma symptom days, more caretaker interrupted sleep, and more school days missed than children who were not sensitive or exposed. CONCLUSION: Geographic differences in allergen exposure and sensitivity exist among inner city children. Cockroach exposure and sensitivity predominate in the Northeast, whereas dust mite exposure and sensitivity are highest in the South and Northwest. Cockroach allergen appears to have a greater effect on asthma morbidity than dust mite or pet allergen in these children.

Airborne fungi in the homes of children with asthma in low-income urban communities: The Inner-City Asthma Study.

BACKGROUND: Despite growing evidence of the importance of exposure to fungi as an environmental risk factor for asthma, few data have been reported on the exposure to airborne fungi of asthmatic children living in US inner cities. OBJECTIVE: We sought to examine the spectrum and concentration of fungi in the air inside and outside of the homes of mold-sensitive children with asthma living in US cities. We also analyzed the relationship of the concentration of fungi in indoor air to home characteristics. METHODS: We performed a home environmental survey and measured the concentrations of culturable airborne fungi inside and outside the homes of 414 mold-sensitive children with asthma in 7 urban communities. RESULTS: The airborne fungi encountered indoors generally paralleled those found outdoors, and the similarities between communities were more striking than the differences. Indoor fungal concentrations were correlated with outdoor concentrations measured on the same day, suggesting the need to adjust for the outdoor concentration in analyses by using the indoor concentration as an indicator of the relative moldiness of a home. The concentration of fungi in indoor air in excess of outdoor air-that is, the indoor-outdoor difference-was significantly related to home characteristics, including dampness, having a cat, and cockroach infestation. CONCLUSION: Mold-sensitive children with asthma living in urban communities across the US are exposed to airborne fungi in indoor and outdoor air. The concentrations of fungi are higher in homes with dampness problems, cockroach infestation, and cats. The indoor-outdoor difference in the concentration of airborne fungi may provide a valuable metric for investigations of the role of fungal exposure as a risk factor for asthma.