Validation of Questionnaire-based Case Definitions for Chronic Obstructive Pulmonary Disease.

BACKGROUND: Various questionnaire-based definitions of chronic obstructive pulmonary disease (COPD) have been applied using the US representative National Health and Nutrition Examination Survey (NHANES), but few have been validated against objective lung function data. We validated two prior definitions that incorporated self-reported physician diagnosis, respiratory symptoms, and/or smoking. We also validated a new definition that we developed empirically using gradient boosting, an ensemble machine learning method. METHODS: Data came from 7,996 individuals 40-79 years who participated in NHANES 2007-2012 and underwent spirometry. We considered participants "true" COPD cases if their ratio of postbronchodilator forced expiratory volume in 1 second to forced vital capacity was below 0.7 or the lower limit of normal. We stratified all analyses by smoking history. We developed a gradient boosting model for smokers only; predictors assessed (25 total) included sociodemographics, inhalant exposures, clinical variables, and respiratory symptoms. RESULTS: The spirometry-based COPD prevalence was 26% for smokers and 8% for never smokers. Among smokers, using questionnaire-based definitions resulted in a COPD prevalence ranging from 11% to 16%, sensitivity ranging from 18% to 35%, and specificity ranging from 88% to 92%. The new definition classified participants based on age, bronchodilator use, body mass index (BMI), smoking pack-years, and occupational organic dust exposure, and resulted in the highest sensitivity (35%) and specificity (92%) among smokers. Among never smokers, the COPD prevalence ranged from 4% to 5%, and we attained good specificity (96%) at the expense of sensitivity (9-10%). CONCLUSION: Our results can be used to parametrize misclassification assumptions for quantitative bias analysis when pulmonary function data are unavailable.

Bedroom Allergen Exposure Beyond House Dust Mites.

PURPOSE OF REVIEW: The review provides insight into recent findings on bedroom allergen exposures, primarily focusing on pet, pest, and fungal exposures. RECENT FINDINGS: Large-scale studies and improved exposure assessment technologies, including measurement of airborne allergens and of multiple allergens simultaneously, have extended our understanding of indoor allergen exposures and their impact on allergic disease. Practical, streamlined methods for exposure reduction have shown promise in some settings, and potential protective effects of early-life exposures have been further elucidated through the investigation of specific bacterial taxa. Advances in molecular allergology have yielded novel data on sensitization profiles and cross-reactivity. The role of indoor allergen exposures in allergic disease is complex and remains incompletely understood. Advancing our knowledge of various co-exposures, including the environmental and host microbiome, that interact with allergens in early life will be crucial for the development of efficacious interventions to reduce the substantial economic and social burden of allergic diseases including asthma.

Exposure and Sensitization to Pets Modify Endotoxin Association with Asthma and Wheeze.

BACKGROUND: Pets are major contributors of endotoxin in homes, but whether they influence endotoxin association with respiratory outcomes is unclear. OBJECTIVE: To examine whether exposure and sensitization to dog and cat modify the relationship between endotoxin exposure and asthma and wheeze. METHODS: We analyzed data from 6051 participants in the 2005-2006 cycle of the National Health and Nutrition Examination Survey (NHANES). House dust from bedroom floor and bedding was evaluated for endotoxin and for dog (Canis familiaris 1) and cat (Feline domesticus 1) allergens. The NHANES also collected data on respiratory outcomes and measured IgE specific to allergens. Associations of log-endotoxin and pet exposure with respiratory outcomes were examined, adjusting for covariates including pet avoidance. RESULTS: Dog and cat ownership among participants was 48.3% and 37.5%, respectively. Endotoxin geometric mean (SE) was 15.49 (0.50) EU/mg. Endotoxin and pet allergen levels were significantly higher in households with a dog or cat. Overall, endotoxin was positively associated with wheeze (odds ratio [OR], 1.30; 95% CI, 1.04-1.62), but not with asthma. However, in participants nonsensitized to dog, the odds of endotoxin association with wheeze were higher with exposure to dog allergen (OR, 1.80; 95% CI, 1.27-2.53; Pinteraction = .048). In participants sensitized to cat and exposed to cat allergen, endotoxin became positively associated with asthma (OR, 1.92; 95% CI, 1.21-3.0; Pinteraction = .040). With coexposure to dog and cat allergens, endotoxin association with asthma and wheeze was exacerbated (OR, 2.00; 95% CI, 1.04-3.83; Pinteraction = .012 and OR, 1.88; 95% CI, 1.32-2.66; Pinteraction = .016, respectively). CONCLUSIONS: Exposure to dog and cat allergens enhances the association of endotoxin with asthma and wheeze.

House Dust Endotoxin Association with Chronic Bronchitis and Emphysema.

BACKGROUND: Endotoxin has been reported to be associated with chronic bronchitis or emphysema (CBE) at high occupational exposures. However, whether levels found in domestic environments have similar effects is unknown. OBJECTIVES: We aimed to study the association between house dust endotoxin and CBE in a sample representative of the U.S. population. METHODS: We analyzed data from 3,393 participants ≥20 y old from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. House dust from bedding and from bedroom floors was analyzed for endotoxin content. NHANES participants received questionnaires and underwent examination as well as extensive laboratory testing. Logistic regression was used to examine the association of endotoxin levels with CBE diagnosis and symptoms, adjusting for covariates. The survey design and weights were applied so that estimates were nationally representative and so that statistical inferences were made appropriately. RESULTS: The median endotoxin concentration in house dust was 14.61 EU/mg dust, and CBE was reported by 8.2% of participants. In the adjusted analysis, one unit (EU/mg) increase in log10-transformed endotoxin concentrations was associated with a 27% increase in the odds of CBE diagnosis [OR=1.27 (95% CI: 1.00, 1.61)] and a 78% increase in the odds of chronic bronchitis symptoms (defined as cough and phlegm for ≥3 mo in a year for ≥2 y) [OR=1.78 (95% CI: 1.01, 3.12)]. Sensitization to inhalant allergens (p=0.001) modified the relationship between endotoxin and CBE diagnosis, with stronger associations observed in sensitized participants [OR=2.46 (95% CI: 1.72, 3.50) for a unit increase in log10-endotoxin]. CONCLUSIONS: In a population-based sample of U.S. adults, endotoxin levels in homes were associated with a self-reported history of CBE diagnosis and chronic bronchitis symptoms, with stronger associations among people sensitized to inhalant allergens. https://doi.org/10.1289/EHP2452.

Clinician Agreement, Self-Efficacy, and Adherence with the Guidelines for the Diagnosis and Management of Asthma.

BACKGROUND: The 2007 Guidelines for the Diagnosis and Management of Asthma provide evidence-based recommendations to improve asthma care. Limited national-level data are available about clinician agreement and adherence to these guidelines. OBJECTIVE: To assess clinician-reported adherence with specific guideline recommendations, as well as agreement with and self-efficacy to implement guidelines. METHODS: We analyzed 2012 National Asthma Survey of Physicians data for 1412 primary care clinicians and 233 asthma specialists about 4 cornerstone guideline domains: asthma control, patient education, environmental control, and pharmacologic treatment. Agreement and self-efficacy were measured using Likert scales; 2 overall indices of agreement and self-efficacy were compiled. Adherence was compared between primary care clinicians and asthma specialists. Logistic regression models assessed the association of agreement and self-efficacy indices with adherence. RESULTS: Asthma specialists expressed stronger agreement, higher self-efficacy, and greater adherence with guideline recommendations than did primary care clinicians. Adherence was low among both groups for specific core recommendations, including written asthma action plan (30.6% and 16.4%, respectively; P < .001); home peak flow monitoring, (12.8% and 11.2%; P = .34); spirometry testing (44.7% and 10.8%; P < .001); and repeated assessment of inhaler technique (39.7% and 16.8%; P < .001). Among primary care clinicians, greater self-efficacy was associated with greater adherence. For specialists, self-efficacy was associated only with increased odds of spirometry testing. Guideline agreement was generally not associated with adherence. CONCLUSIONS: Agreement with and adherence to asthma guidelines was higher for specialists than for primary care clinicians, but was low in both groups for several key recommendations. Self-efficacy was a good predictor of guideline adherence among primary care clinicians but not among specialists.

Sensitization and Exposure to Pets: The Effect on Asthma Morbidity in the US Population.

BACKGROUND: Although pets are found in more than 50% of US homes, the effect of pet allergen exposure on asthma morbidity in the US population is not well documented. OBJECTIVE: To determine the effect of dog and cat allergen exposures on asthma morbidity in the US population. METHODS: The National Health and Nutrition Examination Survey is a representative sample of civilian US population. Data on asthma, dog and cat allergen levels in bedroom dust, as well as specific IgE to dog and cat were analyzed for all participants 6 years or older. RESULTS: Pets are common in the United States, with more that 50% of households having a dog or a cat or both. The prevalence of allergic sensitization in the National Health and Nutrition Examination Survey population was similar for dog and cat, with both being approximately 12%. Among those who were sensitized, exposure to elevated levels of pet allergens was associated with an increased prevalence of asthma and asthma attacks. Indeed, 44.2% of the asthma attacks were attributable to exposure to high levels of dog allergen in the bedroom among patients with asthma sensitive to dog and 30.3% were attributable to cat allergen exposure among the comparable cat-sensitive and exposed group. Projecting these results to the US population indicates more than 1 million increased asthma attacks each year for the dog-sensitive and exposed group and more than 500,000 increased asthma attacks for the cat-sensitive and exposed population of patients with asthma. CONCLUSIONS: Exposure to elevated levels of dog and cat allergens among those sensitized individuals with asthma is associated with excess asthma attacks. Reducing pet allergen exposures has the potential for a significant decrease in asthma morbidity.

Bedroom allergen exposures in US households.

BACKGROUND: Bedroom allergen exposures contribute to allergic disease morbidity because people spend considerable time in bedrooms, where they come into close contact with allergen reservoirs. OBJECTIVE: We investigated participant and housing characteristics, including sociodemographic, regional, and climatic factors, associated with bedroom allergen exposures in a nationally representative sample of the US population. METHODS: Data were obtained from National Health and Nutrition Examination Survey 2005-2006. Information on participant and housing characteristics was collected by using questionnaires and environmental assessments. Concentrations of 8 indoor allergens (Alt a 1, Bla g 1, Can f 1, Fel d 1, Der f 1, Der p 1, Mus m 1, and Rat n 1) in dust vacuumed from nearly 7000 bedrooms were measured by using immunoassays. Exposure levels were classified as increased based on percentile (75th/90th) cutoffs. We estimated the burden of exposure to multiple allergens and used multivariable logistic regression to identify independent predictors for each allergen and household allergen burden. RESULTS: Almost all participants (>99%) had at least 1 and 74.2% had 3 to 6 allergens detected. More than two thirds of participants (72.9%) had at least 1 allergen and 18.2% had 3 or more allergens exceeding increased levels. Although exposure variability showed significant racial/ethnic and regional differences, high exposure burden to multiple allergens was most consistently associated with the presence of pets and pests, living in mobile homes/trailers and older and rental homes, and living in nonmetropolitan areas. CONCLUSIONS: Exposure to multiple allergens is common. Despite highly variable exposures, bedroom allergen burden is strongly associated with the presence of pets and pests.

Endotoxin predictors and associated respiratory outcomes differ with climate regions in the U.S.

RATIONALE: Although endotoxin is a recognized cause of environmental lung disease, how its relationship with respiratory outcomes varies with climate is unknown. OBJECTIVE: To examine the endotoxin predictors as well as endotoxin association with asthma, wheeze, and sensitization to inhalant allergens in various US climate regions. METHODS: We analyzed data on 6963 participants in the National Health and Nutrition Examination Survey. Endotoxin measurements of house dust from bedroom floor and bedding were performed at the University of Iowa. Linear and logistic regression analyses were used to identify endotoxin predictors and assess endotoxin association with health outcomes. RESULTS: The overall median house dust endotoxin was 16.2 EU/mg; it was higher in mixed-dry/hot-dry regions (19.7 EU/mg) and lower in mixed-humid/marine areas (14.8 EU/mg). Endotoxin predictors and endotoxin association with health outcomes significantly differed across climate regions. In subarctic/very cold/cold regions, log10-endotoxin was significantly associated with higher prevalence of wheeze outcomes (OR:1.48, 95% CI:1.19-1.85 for any wheeze, OR:1.48, 95% CI:1.22-1.80 for exercise-induced wheeze, OR:1.50, 95% CI:1.13-1.98 for prescription medication for wheeze, and OR:1.95, 95% CI:1.50-2.54 for doctor/ER visit for wheeze). In hot-humid regions, log10-endotoxin was positively associated with any wheeze (OR:1.66, 95% CI:1.04-2.65) and current asthma (OR:1.56, 95% CI:1.11-2.18), but negatively with sensitization to any inhalant allergens (OR:0.83, 95% CI:0.74-0.92). CONCLUSION: Endotoxin predictors and endotoxin association with asthma and wheeze differ across U.S. climate regions. Endotoxin is associated positively with wheeze or asthma in cold and hot-humid regions, but negatively with sensitization to inhalant allergens in hot-humid climates.

House Dust Endotoxin and Peripheral Leukocyte Counts: Results from Two Large Epidemiologic Studies.

BACKGROUND: The peripheral leukocyte count is a biomarker of inflammation and is associated with human all-cause mortality. Although causes of acute leukocytosis are well-described, chronic environmental determinants of leukocyte number are less well understood. OBJECTIVES: We investigated the relationship between house dust endotoxin concentration and peripheral leukocyte counts in human subjects. METHODS: The endotoxin­leukocyte relationship was evaluated by linear regression in the National Health and Nutrition Examination Survey (NHANES) 2005­2006 (n=6,254) and the Agricultural Lung Health Study (ALHS; n=1,708). In the ALHS, we tested for a gene [Toll-like Receptor 4 (TLR4), encoding the endotoxin receptor]-by-environment interaction in the endotoxin­leukocyte relationship using regression models with an interaction term. RESULTS: There is a statistically significant, positive association between endotoxin concentration and total leukocyte number [estimated change, 0.186×103/µL (95% CI: 0.070, 0.301×103/µL) per 10-fold change in endotoxin; p=0.004) in the NHANES. Similar positive associations were found for monocytes, lymphocytes, and neutrophils. Stratified analyses revealed possible effect modification by asthma and chronic obstructive pulmonary disease. We observed similar associations in the ALHS. For total leukocytes, there was suggestive evidence in the ALHS of a gene-by-environment interaction for minor allele carrier status at the TLR4 haplotype defined by rs4986790 and rs4986791 (interaction p=0.15). CONCLUSIONS: This is, to our knowledge, the first report of an association between house dust endotoxin and leukocyte count in a national survey. The finding was replicated in a farming population. Peripheral leukocyte count may be influenced by residential endotoxin exposure in diverse settings. https://doi.org/10.1289/EHP661.

From Design to Dissemination: Implementing Community-Based Participatory Research in Postdisaster Communities.

OBJECTIVES: To review how disasters introduce unique challenges to conducting population-based research and community-based participatory research (CBPR). METHODS: From 2007-2009, we conducted the Head-off Environmental Asthma in Louisiana (HEAL) Study in the aftermath of Hurricane Katrina in a Gulf Coast community facing an unprecedented triple burden: Katrina's and other disasters' impact on the environment and health, historic health disparities, and persistent environmental health threats. RESULTS: The unique triple burden influenced every research component; still, most existing CBPR principles were applicable, even though full adherence was not always feasible and additional tailored principles govern postdisaster settings. CONCLUSIONS: Even in the most challenging postdisaster conditions, CBPR can be successfully designed, implemented, and disseminated while adhering to scientific rigor.

Adapting and implementing an evidence-based asthma counseling intervention for resource-poor populations.

OBJECTIVE: To report implementation strategies and outcomes of an evidence-based asthma counseling intervention. The Head-off Environmental Asthma in Louisiana (HEAL) intervention integrated asthma counseling (AC) capacity and addressed challenges facing children with asthma in post-disaster New Orleans. METHODS: The HEAL intervention enrolled 182 children (4-12 years) with moderate-to-severe persistent asthma. Recruitment occurred from schools in the Greater New Orleans area for one year. Participants received home environmental assessments and tailored asthma counseling sessions during the study period based on the National Cooperative Inner City Asthma Study and the Inner City Asthma Study. Primary (i.e., asthma symptoms) and secondary outcomes (i.e., healthcare utilization) were captured. During the study, changes were made to meet the demands of a post-hurricane and resource-poor environment which included changes to staffing, training, AC tools, and AC sessions. RESULTS: After study changes were made, the AC visit rate increased by 92.3%. Significant improvements were observed across several adherence measures (e.g., running out of medications (p = 0.009), financial/insurance problems for appointments (p = 0.006), worried about medication side-effects (p = 0.01), felt medications did not work (p < 0.001)). Additionally, an increasing number of AC visits was modestly associated with a greater reduction in symptoms (test-for-trend p = 0.059). CONCLUSION: By adapting to the needs of the study population and setting, investigators successfully implemented a counseling intervention that improved participant behaviors and clinical outcomes. The strategies for implementing the AC intervention may serve as a guide for managing asthma and other chronic conditions in resource-poor settings.

Endotoxin exposure, serum vitamin D, asthma and wheeze outcomes.

BACKGROUND: Endotoxin has been shown to induce neutrophilic asthma and wheeze after binding toll-like receptor 4 to produce pro-inflammatory cytokines. Animal models have demonstrated that vitamin D might inhibit lipopolysaccharide-induced cytokines. However, whether endotoxin exposure and serum vitamin D deficiency interact to affect asthma and wheeze in humans has never been investigated in an epidemiological study. METHODS: Joint associations of house dust endotoxin and vitamin D with asthma and wheeze were examined using logistic regression adjusted for covariates in 5924 US participants of the National Health and Nutrition Examination Survey (NHANES). Interactions were assessed on the multiplicative as well as additive scale using the relative excess risk, the attributable portion due to additive interaction, and the synergy index. RESULTS: The median endotoxin concentration was 19.1 EU/mg. Prevalence of vitamin D inadequacy (20-30 ng/ml) and deficiency (<20 ng/ml) were respectively 42.9 and 33.4%. The combination of high endotoxin and low vitamin D was associated with current asthma (OR: 1.56, 95% CI: 1.09, 2.23), wheeze in the past 12 months (OR: 1.72, 95% CI: 1.10, 3.71), recurrent wheeze (OR: 1.97, 95% CI: 1.00, 4.00), asthma diagnosis or recurrent wheeze (OR: 1.88, 95% CI: 1.33, 2.66), and current asthma or recurrent wheeze (OR:1.81, 95% CI: 1.23, 2.68) when compared to low endotoxin and normal vitamin D. The interactions between the exposures were not significant on the multiplicative or additive scale for any of the outcomes. CONCLUSIONS: Combination of high endotoxin exposure and low vitamin D increases the odds of asthma and wheeze, but the exposures do not interact or modify each other's effect in the NHANES cohort.

Efficacy of an in-home test kit in reducing dust mite allergen levels: results of a randomized controlled pilot study.

BACKGROUND: Dust mite allergens can induce allergic sensitization and exacerbate asthma symptoms. Although dust mite reduction and control strategies exist, few asthmatics employ them. OBJECTIVES: We examined whether an in-home test kit, which quantifies dust mite allergen levels, resulted in behavioral changes in implementation and maintenance of mite reduction strategies and helped reduce allergen levels in homes of dust mite-sensitive children. METHODS: We enrolled 60 households of children aged 5-15 with parent-reported dust mite allergy into a randomized controlled trial. Intervention homes (N = 30) received educational material about reducing dust mites and test kits at 1, 2, 5 and 8 months. Control homes (N = 30) received only educational material. At baseline, 6 and 12 months, study staff visited all homes, collected dust samples from three locations and obtained information about parents' mite reduction behaviors by questionnaire. Allergen concentrations (Der f 2/Der p2) in dust were assessed by immunoassays. After adjusting for visit and location, allergen concentrations in intervention and control homes were compared using mixed effects model analysis. RESULTS: In the intervention homes, allergen concentrations in the child's bedroom and living room floors were significantly reduced over time compared to control homes. Although not all location-specific differences in allergen concentrations were statistically significant, combining data across locations, there was a differential reduction in allergen concentrations in the intervention group versus the control group (p = 0.02). CONCLUSION: The use of in-home test kits along with education may beneficially influence behaviors and attitudes toward dust mite reduction strategies and help reduce residential dust mite allergen levels.

Nitrogen dioxide and allergic sensitization in the 2005-2006 National Health and Nutrition Examination Survey.

BACKGROUND: Allergic sensitization is a risk factor for asthma and allergic diseases. The relationship between ambient air pollution and allergic sensitization is unclear. OBJECTIVE: To investigate the relationship between ambient air pollution and allergic sensitization in a nationally representative sample of the US population. METHODS: We linked annual average concentrations of nitrogen dioxide (NO2), particulate matter ≤10 µm (PM10), particulate matter ≤2.5 µm (PM2.5), and summer concentrations of ozone (O3), to allergen-specific immunoglobulin E (IgE) data for participants in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). In addition to the monitor-based air pollution estimates, we used the Community Multiscale Air Quality (CMAQ) model to increase the representation of rural participants in our sample. Logistic regression with population-based sampling weights was used to calculate adjusted prevalence odds ratios per 10 ppb increase in O3 and NO2, per 10 µg/m(3) increase in PM10, and per 5 µg/m(3) increase in PM2.5 adjusting for race, gender, age, socioeconomic status, smoking, and urban/rural status. RESULTS: Using CMAQ data, increased levels of NO2 were associated with positive IgE to any (OR 1.15, 95% CI 1.04, 1.27), inhalant (OR 1.17, 95% CI 1.02, 1.33), and indoor (OR 1.16, 95% CI 1.03, 1.31) allergens. Higher PM2.5 levels were associated with positivity to indoor allergen-specific IgE (OR 1.24, 95% CI 1.13, 1.36). Effect estimates were similar using monitored data. CONCLUSIONS: Increased ambient NO2 was consistently associated with increased prevalence of allergic sensitization.

Characteristics of allergic sensitization among asthmatic adults older than 55 years: results from the National Health and Nutrition Examination Survey, 2005-2006.

BACKGROUND: Approximately 60% to 80% of children and young adults with asthma are sensitized to at least one allergen. In contrast, previous studies from specific subpopulations of older patients with asthma suggest that allergic sensitization is significantly lower in this age group. The prevalence and patterns of IgE-mediated sensitization have not been compared among a broad population of younger and older patients with asthma. OBJECTIVE: To determine the prevalence and patterns of IgE-mediated sensitization among a broad population of younger and older patients with asthma. METHODS: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 to compare IgE-mediated sensitization rates between younger (20-40 years) and older (≥55 years) patients with current asthma. Atopy was defined as a detectable serum IgE to at least 1 allergen in a panel of 19 allergens. The associations among sensitization, current asthma, and asthma control measures (health care use and symptoms) were examined by logistic regression. RESULTS: In a group of 2,573 patients, either 20 to 40 years of age or 55 years or older, 108 (6.7%) and 43 (4.5%) patients with current asthma were identified, respectively. Allergic sensitization rates among the adults with asthma differed only moderately and not statistically significantly between the age groups; 75.4% of the younger and 65.2% of the older asthmatic patients were sensitized to at least 1 allergen. The association between sensitization and markers of asthma control did not appear to differ among the age groups. CONCLUSION: Allergic sensitization in older patients with asthma may be more common than previously reported.

Relation between objective measures of atopy and myocardial infarction in the United States.

BACKGROUND: Although rodent studies indicate that atherosclerosis is a T(H)1-mediated disease and that atopic T(H)2 immunity is atheroprotective, findings in humans are conflicting. Total IgE (tIgE) is associated with atherosclerotic disease but has limited specificity for atopy. OBJECTIVE: Our aim was to determine the relation between atopy, as indicated by a broad panel of serum allergen-specific IgE (sIgE), and past myocardial infarction (MI) in a sample representative of the US population. METHODS: Data were analyzed from 4002 participants aged ≥ 20 years from the 2005-2006 National Health and Nutrition Examination Survey. RESULTS: Subjects reporting a history of MI had lower summed sIgE (5.51 vs 7.71 kU/L; P < .001) and were less likely to have ≥ 1 positive sIgE test (29.9% vs 44.6%; P = .02) or current hay fever (3.3% vs 7.6%; P = .002). After adjustment for age, sex, race/ethnicity, diabetes mellitus, hypertension, family history of MI, smoking, total/high-density lipoprotein cholesterol, body mass index, and C-reactive protein, the odds ratio (OR) for MI was 0.91 (95% CI, 0.85-0.97) per positive sIgE; 0.70 (95% CI, 0.57-0.85) per 2-fold increase in sum[sIgE]; and 0.82 (95% CI, 0.69-0.98) per 10% increase in the ratio of sum[sIgE] to tIgE. Analysis with 7 data-driven, prespecified allergen clusters found that house dust mite is the only allergen cluster for which sIgE is associated with reduced odds for MI (fully adjusted OR, 0.36; 95% CI, 0.20-0.64). CONCLUSION: Serum sIgE is inversely related to MI in the US population in a manner independent of multiple coronary risk factors.

Implementation of evidence-based asthma interventions in post-Katrina New Orleans: the Head-off Environmental Asthma in Louisiana (HEAL) study.

BACKGROUND: Childhood asthma morbidity and mortality in New Orleans, Louisiana, is among the highest in the nation. In August 2005, Hurricane Katrina created an environmental disaster that led to high levels of mold and other allergens and disrupted health care for children with asthma. OBJECTIVES: We implemented a unique hybrid asthma counselor and environmental intervention based on successful National Institutes of Health asthma interventions from the National Cooperative Inner City Asthma (NCICAS) and Inner-City Asthma (ICAS) Studies with the goal of reducing asthma symptoms in New Orleans children after Hurricane Katrina. METHODS: Children (4-12 years old) with moderate-to-severe asthma (n = 182) received asthma counseling and environmental intervention for approximately 1 year. HEAL was evaluated employing several analytical approaches including a pre-post evaluation of symptom changes over the entire year, an analysis of symptoms according to the timing of asthma counselor contact, and a comparison to previous evidence-based interventions. RESULTS: Asthma symptoms during the previous 2 weeks decreased from 6.5 days at enrollment to 3.6 days at the 12-month symptom assessment (a 45% reduction, p < 0.001), consistent with changes observed after NCICAS and ICAS interventions (35% and 62% reductions in symptom days, respectively). Children whose families had contact with a HEAL asthma counselor by 6 months showed a 4.09-day decrease [95% confidence interval (CI): 3.25 to 4.94-day decrease] in symptom days, compared with a 1.79-day decrease (95% CI: 0.90, 2.67) among those who had not yet seen an asthma counselor (p < 0.001). CONCLUSIONS: The novel combination of evidence-based asthma interventions was associated with improved asthma symptoms among children in post-Katrina New Orleans. Post-intervention changes in symptoms were consistent with previous randomized trials of NCICAS and ICAS interventions.

Indoor environmental exposures for children with asthma enrolled in the HEAL study, post-Katrina New Orleans.

BACKGROUND: Rain and flooding from Hurricane Katrina resulted in widespread growth of mold and bacteria and production of allergens in New Orleans, Louisiana, which may have led to increased exposures and morbidity in children with asthma. OBJECTIVES: The goal of the Head-off Environmental Asthma in Louisiana (HEAL) study was to characterize post-Katrina exposures to mold and allergens in children with asthma. METHODS: The homes of 182 children with asthma in New Orleans and surrounding parishes were evaluated by visual inspection, temperature and moisture measurements, and air and dust sampling. Air was collected using vacuum-pump spore traps and analyzed for > 30 mold taxa using bright field microscopy. Dust was collected from the children's beds and bedroom floors and analyzed for mouse (Mus m 1), dust mite (Der p 1), cockroach (Bla g 1), and mold (Alternaria mix) allergens using ELISA. RESULTS: More than half (62%) of the children were living in homes that had been damaged by rain, flooding, or both. Geometric mean indoor and outdoor airborne mold levels were 501 and 3,958 spores/m3, respectively. Alternaria antigen was detected in dust from 98% of homes, with 58% having concentrations > 10 µg/g. Mus m 1, Der p 1, and Bla g 1 were detected in 60%, 35%, and 20% of homes, respectively, at low mean concentrations. CONCLUSIONS: Except for Alternaria antigen in dust, concentrations of airborne mold (ratio of indoor to outdoor mold) and dust allergens in the homes of HEAL children were lower than measurements found in other studies, possibly because of extensive post-Katrina mold remediation and renovations, or because children moved into cleaner homes upon returning to New Orleans.

The Head-off Environmental Asthma in Louisiana (HEAL) study--methods and study population.

BACKGROUND: In the city of New Orleans, Louisiana, and surrounding parishes (NOLA), children with asthma were perilously impacted by Hurricane Katrina as a result of disrupted health care, high home mold and allergen levels, and high stress. OBJECTIVES: The Head-off Environmental Asthma in Louisiana (HEAL) study was conducted to examine relationships between the post-Katrina environment and childhood asthma in NOLA and assess a novel asthma counselor intervention that provided case management and guidance for reducing home mold and allergen levels. METHODS: Children (4-12 years old) with moderate-to-severe asthma were recruited from NOLA schools. Over 1 year, they received two clinical evaluations, three home environmental evaluations, and the asthma intervention. Quarterly end points included symptom days, medication use, and unscheduled emergency department or clinic visits. A community advisory group was assembled and informed HEAL at all phases. RESULTS: Of the children (n = 182) enrolled in HEAL, 67% were African American, and 25% came from households with annual incomes < $15,000. HEAL children were symptomatic, averaging 6.6 symptom days in the 2 weeks before baseline, and had frequent unscheduled visits to clinics or emergency departments (76% had at least one unscheduled visit in the preceding 3 months). In this report, we describe study design and baseline characteristics of HEAL children. CONCLUSIONS: Despite numerous challenges faced by investigators, study staff, and participants, including destroyed infrastructure, disrupted lives, and lost jobs, HEAL was successful in terms of recruitment and retention, the high quality of data collected that will provide insight into asthma-allergen relationships, and the asthma intervention. This success was attributable to using an adaptive approach and refining processes as needed.