Management of asthma requires attention to environmental exposures both indoors and outdoors. Americans spend most of their time indoors, where they have a greater ability to modify their environment. The indoor environment contains both pollutants (eg, particulate matter, nitrogen dioxide, secondhand smoke, and ozone) and allergens from furred pets, dust mites, cockroaches, rodents, and molds. Indoor particulate matter consists of particles generated from indoor sources such as cooking and cleaning activities, and particles that penetrate from the outdoors. Nitrogen dioxide sources include gas stoves, furnaces, and fireplaces. Indoor particulate matter and nitrogen dioxide are linked to asthma morbidity. The indoor ozone concentration is mainly influenced by the outdoor ozone concentration. The health effects of indoor ozone exposure have not been well studied. In contrast, there is substantial evidence of detrimental health effects from secondhand smoke. Guideline recommendations are not specific for optimizing indoor air quality. The 2007 National Asthma Education and Prevention Program asthma guidelines recommend eliminating indoor smoking and improving the ventilation. Though the guidelines state that there is insufficient evidence to recommend air cleaners, air cleaners and reducing activities that generate indoor pollutants may be sound practical approaches for improving the health of individuals with asthma. The guidelines are more specific about allergen avoidance; they recommend identifying allergens to which the individual is immunoglobin E sensitized and employing a multifaceted, comprehensive strategy to reduce exposure. Outdoor air pollutants that impact asthma include particulate matter, ozone, nitrogen dioxide, and sulfur dioxide, and guidelines recommend that individuals with asthma avoid exertion outdoors when these pollutants are elevated. Outdoor allergens include tree, grass, and weed pollens, which vary in concentration by season. Recommendations to reduce exposure include staying indoors, keeping windows and doors closed, using air conditioning and perhaps high-efficiency particulate arrestor (HEPA) air filters, and thorough daily washing to remove allergens from one’s person.
asthma; pollutants; particulate matter; nitrogen dioxide; sulfur dioxide; secondhand smoke; ozone; allergens
National Institutes of Health asthma guidelines recommend questionnaires to assess asthma control, but these questionnaires are not useable across the entire pediatric age spectrum and have not been validated among significant numbers of minority or Spanish-speaking children.
We sought to evaluate a questionnaire designed to assess asthma control across a broad age range of minority and Spanish-speaking children cared for in an outpatient setting.
Between July 1, 2007, and September 30, 2010, we collected information using the Pediatric Asthma Control and Communication Instrument (PACCI), the Asthma Control Test (ACT; or the childhood ACT for children 4–11 years old), the Pediatric Asthma Caregiver Quality of Life Questionnaire, and lung function and clinicians’ ratings of asthma status among a population of children presenting for routine asthma specialist care. The PACCI measure of asthma control was validated by evaluating accuracy, internal reliability, and concurrent, discriminative, and known-groups validity.
We collected information on 265 English- and 52 Spanish-speaking children (mean age, 8.2 years; 58% male; 44% African American). Across all age groups and in both languages, PACCI control showed good internal reliability and strong concurrent, discriminative, and known-groups validity with ACT and Pediatric Asthma Caregiver Quality of Life Questionnaire scores and clinicians’ ratings of asthma control. The accuracy of the PACCI in classifying children with uncontrolled asthma was good (area under the curve, 0.83; 95% CI, 0.79–0.88).
The PACCI accurately measures asthma control in English- and Spanish-speaking children. The PACCI should be useful to clinicians to assess and classify asthma according to National Institutes of Health asthma guidelines.
Impairment; control; children; assessment; accuracy; survey; validation; Pediatric Asthma Control and Communication Instrument; Spanish
Rationale: The effect of endotoxin on asthma morbidity in urban populations is unclear.
Objectives: To determine if indoor pollutant exposure modifies the relationships between indoor airborne endotoxin and asthma health and morbidity.
Methods: One hundred forty-six children and adolescents with persistent asthma underwent repeated clinical assessments at 0, 3, 6, 9, and 12 months. Home visits were conducted at the same time points for assessment of airborne nicotine, endotoxin, and nitrogen dioxide (NO2) concentrations. The effect of concomitant pollutant exposure on relationships between endotoxin and asthma outcomes were examined in stratified analyses and statistical models with interaction terms.
Measurements and Main Results: Both air nicotine and NO2 concentrations modified the relationships between airborne endotoxin and asthma outcomes. Among children living in homes with no detectable air nicotine, higher endotoxin was inversely associated with acute visits and oral corticosteroid bursts, whereas among those in homes with detectable air nicotine, endotoxin was positively associated with these outcomes (interaction P value = 0.004 and 0.07, respectively). Among children living in homes with lower NO2 concentrations (<20 ppb), higher endotoxin was positively associated with acute visits, whereas among those living in homes with higher NO2 concentrations, endotoxin was negatively associated with acute visit (interaction P value = 0.05). NO2 also modified the effect of endotoxin on asthma symptom outcomes in a similar manner.
Conclusions: The effects of household airborne endotoxin exposure on asthma are modified by coexposure to air nicotine and NO2, and these pollutants have opposite effects on the relationships between endotoxin and asthma-related outcomes.
childhood asthma; endotoxin; indoor pollution; nitrogen dioxide; second-hand smoke
Cockroach and mouse allergens have both been implicated as causes in
inner-city asthma morbidity in multicenter studies, but whether both
allergens are clinically relevant within specific inner-city communities is
unclear. Objective: Our study aimed to identify relevant allergens in
One hundred forty-four children (5–17 years old) with asthma
underwent skin prick tests at baseline and had clinical data collected at
baseline and 3, 6, 9, and 12 months. Home settled dust samples were
collected at the same time points for quantification of indoor allergens.
Participants were grouped based on their sensitization and exposure status
to each allergen. All analyses were adjusted for age, sex, and serum total
Forty-one percent were mouse sensitized/exposed, and 41% were
cockroach sensitized/exposed based on bedroom floor exposure data. Mouse
sensitization/exposure was associated with acute care visits, decreased
FEV1/forced vital capacity percentage values, fraction of
exhaled nitric oxide levels, and bronchodilator reversibility. Cockroach
sensitization/exposure was only associated with acute care visits and
bronchodilator reversibility when exposure was defined by using bedroom
floor allergen levels. Mouse-specific IgE levels were associated with poor
asthma health across a range of outcomes, whereas cockroach-specific IgE
levels were not. The relationships between asthma outcomes and mouse
allergen were independent of cockroach allergen. Although
sensitization/exposure to both mouse and cockroach was generally associated
with worse asthma, mouse sensitization/exposure was the primary contributor
to these relationships.
In a community with high levels of both mouse and cockroach
allergens, mouse allergen appears to be more strongly and consistently
associated with poor asthma outcomes than cockroach allergen.
Community-level asthma interventions in Baltimore should prioritize reducing
mouse allergen exposure.
Inner-city asthma; childhood asthma; mouse allergen; cockroach allergen; indoor allergens
Epidemiologic findings support a positive association between asthma and obesity.
Determine whether obesity or increasing level of body mass index (BMI) are associated with worse asthma control in an ethnically diverse urban population.
Cross sectional assessment of asthma control was done in asthmatics recruited from primary care offices using four different validated asthma control questionnaires: the Asthma Control and Communication Instrument (ACCI), the Asthma Control Test (ACT), the Asthma Control Questionnaire (ACQ) and the Asthma Therapy Assessment Questionnaire (ATAQ). Multiple linear regression analysis was performed to evaluate the association between obesity and increasing BMI level and asthma control.
Of 292 subjects mean age of 47 years, the majority were women (82%) and African American (67%). There was a high prevalence of obesity with 63%, with only 15% being normal weight. The mean score from all four questionnaires showed an average sub-optimal asthma control (mean score/maximum possible score): ACCI (8.3/19), ACT (15.4/ 25), ACQ (2.1/ 6), and ATAQ (1.3/ 4). Regression analysis showed no association between obesity or increasing BMI level and asthma control using all four questionnaires. This finding persisted even after adjusting for FEV1, smoking status, race, gender, selected co-morbid illnesses, and long-term asthma controller use.
Using four validated asthma control questionnaires, we failed to find an association between obesity and asthma control in an urban population with asthma. Weight loss may not be an appropriate strategy to improve asthma control in this population.
Using four different validated asthma control measures, there was no association between obesity or increasing body mass index and asthma control in a largely obese urban outpatient minority population.
asthma; asthma Control; obesity; overweight; body mass index; inner city; asthma communication control instrument; ACCI; African-American
Indoor particulate matter (PM) has been linked to respiratory symptoms in former smokers with COPD. While subjects with COPD and atopy have also been shown to have more frequent respiratory symptoms, whether they exhibit increased susceptibility to PM as compared to their non-atopic counterparts remains unclear. The aim of this study was to determine whether atopic individuals with COPD have greater susceptibility to PM compared to non-atopic individuals with COPD.
Former smokers with moderate to severe COPD were enrolled (n = 77). PM2.5, PM with diameter <2.5 micrometers, was measured in the main living area over three one-week monitoring periods at baseline, 3, and 6 months. Quality of life, respiratory symptoms and medication use were assessed by questionnaires. Serum was analyzed for specific IgE for mouse, cockroach, cat, dog and dust mite allergens. Atopy was established if at least one test was positive. Interaction terms between PM and atopy were tested and generalized estimating equation analysis determined the effect of PM concentrations on health outcomes. Multivariate models were adjusted for age, sex, education, race, season, and baseline lung function and stratified by atopic status.
Among atopic individuals, each 10 μg/m3 increase in PM was associated with higher risk of nocturnal symptoms (OR, 1.95; P = 0.02), frequent wheezing (OR, 2.49; P = 0.02), increased rescue medication use (β = 0.14; P = 0.02), dyspnea (β = 0.23; P < 0.001), higher St. George’s Respiratory Quality of Life score (β = 2.55; P = 0.01), and higher breathlessness, cough, and sputum score (BCSS) (β = 0.44; P = 0.01). There was no association between PM and health outcomes among the non-atopic individuals. Interaction terms between PM2.5 and atopy were statistically significant for nocturnal symptoms, frequency of rescue medication use, and BCSS (all P < 0.1).
Individuals with COPD and atopy appear to be at higher risk of adverse respiratory health effects of PM exposure compared to non-atopic individuals with COPD.
COPD; Atopy; Allergic sensitization; Pollutants; Particulate matter; PM; Indoor air; Susceptibility
BACKGROUND AND OBJECTIVE:
Health care provider adherence to asthma guidelines is poor. The objective of this study was to assess the effect of interventions to improve health care providers’ adherence to asthma guidelines on health care process and clinical outcomes.
Data sources included Medline, Embase, Cochrane CENTRAL Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Educational Resources Information Center, PsycINFO, and Research and Development Resource Base in Continuing Medical Education up to July 2012. Paired investigators independently assessed study eligibility. Investigators abstracted data sequentially and independently graded the evidence.
Sixty-eight eligible studies were classified by intervention: decision support, organizational change, feedback and audit, clinical pharmacy support, education only, quality improvement/pay-for-performance, multicomponent, and information only. Half were randomized trials (n = 35). There was moderate evidence for increased prescriptions of controller medications for decision support, feedback and audit, and clinical pharmacy support and low-grade evidence for organizational change and multicomponent interventions. Moderate evidence supports the use of decision support and clinical pharmacy interventions to increase provision of patient self-education/asthma action plans. Moderate evidence supports use of decision support tools to reduce emergency department visits, and low-grade evidence suggests there is no benefit for this outcome with organizational change, education only, and quality improvement/pay-for-performance.
Decision support tools, feedback and audit, and clinical pharmacy support were most likely to improve provider adherence to asthma guidelines, as measured through health care process outcomes. There is a need to evaluate health care provider-targeted interventions with standardized outcomes.
asthma; systematic review; guidelines
Home mouse allergen exposure is associated with asthma morbidity, but little is known about the shape of the dose-response relationship or the relevance of location of exposure within the home.
Asthma outcome and allergen exposure data were collected every three months for 1 year in 150 urban children with asthma. Participants were stratified by mouse sensitization and relationships between continuous measures of mouse allergen exposure and outcomes of interest were analyzed.
Every ten-fold increase in the bed mouse allergen level was associated with an 87% increase in the odds of any asthma-related health care use among mouse sensitized (OR (95% CI): 1.87 (1.21–2.88)), but not non-mouse sensitized participants. Similar relationships were observed for emergency department visit and unscheduled doctor visit among mouse sensitized participants. Kitchen floor and bedroom air mouse allergen concentrations were also associated with greater odds of asthma-related healthcare utilization; however, the magnitude of the association was less than that observed for bed mouse allergen concentrations.
In this population of urban children with asthma, there is a linear dose-response relationship between mouse allergen concentrations and asthma morbidity among mouse-sensitized asthmatics. Bed and bedroom air mouse allergen exposure compartments may have a greater impact on asthma morbidity than other compartments.
Mouse allergen; inner-city asthma; childhood asthma; exposure compartments; indoor allergens; asthma morbidity
Rationale: Chronic obstructive pulmonary disease (COPD) guidelines make no recommendations for allergy diagnosis or treatment.
Objectives: To determine whether an allergic phenotype contributes to respiratory symptoms and exacerbations in patients with COPD.
Methods: Two separate cohorts were analyzed: National Health and Nutrition Survey III (NHANES III) and the COPD and domestic endotoxin (CODE) cohort. Subjects from NHANES III with COPD (n = 1,381) defined as age > 40 years, history of smoking, FEV1/FVC < 0.70, and no diagnosis of asthma were identified. The presence of an allergic phenotype (n = 296) was defined as self-reported doctor diagnosed hay fever or allergic upper respiratory symptoms. In CODE, former smokers with COPD (n = 77) were evaluated for allergic sensitization defined as a detectable specific IgE to perennial allergens. Bivariate and multivariate models were used to determine whether an allergic phenotype was associated with respiratory symptoms and exacerbations.
Measurements and Main Results: In NHANES III, multivariate analysis revealed that individuals with allergic phenotype were more likely to wheeze (odds ratio [OR], 2.1; P < 0.01), to have chronic cough (OR, 1.9; P = 0.01) and chronic phlegm (OR, 1.5; P < 0.05), and to have increased risk of COPD exacerbation requiring an acute doctor visit (OR, 1.7; P = 0.04). In the CODE cohort, multivariate analysis revealed that sensitized subjects reported more wheeze (OR, 5.91; P < 0.01), more nighttime awakening due to cough (OR, 4.20; P = 0.03), increased risk of COPD exacerbations requiring treatment with antibiotics (OR, 3.79; P = 0.02), and acute health visits (OR, 11.05; P < 0.01). An increasing number of sensitizations was associated with a higher risk for adverse health outcomes.
Conclusions: Among individuals with COPD, evidence of an allergic phenotype is associated with increased respiratory symptoms and risk of COPD exacerbations.
atopy; allergic sensitization; allergy; chronic obstructive pulmonary disease
Rationale: The effect of indoor air pollutants on respiratory morbidity among patients with chronic obstructive pulmonary disease (COPD) in developed countries is uncertain.
Objectives: The first longitudinal study to investigate the independent effects of indoor particulate matter (PM) and nitrogen dioxide (NO2) concentrations on COPD morbidity in a periurban community.
Methods: Former smokers with COPD were recruited and indoor air was monitored over a 1-week period in the participant’s bedroom and main living area at baseline, 3 months, and 6 months. At each visit, participants completed spirometry and questionnaires assessing respiratory symptoms. Exacerbations were assessed by questionnaires administered at clinic visits and monthly telephone calls.
Measurements and Main Results: Participants (n = 84) had moderate or severe COPD with a mean FEV1 of 48.6% predicted. The mean (± SD) indoor PM2.5 and NO2 concentrations were 11.4 ± 13.3 µg/m3 and 10.8 ± 10.6 ppb in the bedroom, and 12.2 ± 12.2 µg/m3 and 12.2 ± 11.8 ppb in the main living area. Increases in PM2.5 concentrations in the main living area were associated with increases in respiratory symptoms, rescue medication use, and risk of severe COPD exacerbations. Increases in NO2 concentrations in the main living area were independently associated with worse dyspnea. Increases in bedroom NO2 concentrations were associated with increases in nocturnal symptoms and risk of severe COPD exacerbations.
Conclusions: Indoor pollutant exposure, including PM2.5 and NO2, was associated with increased respiratory symptoms and risk of COPD exacerbation. Future investigations should include intervention studies that optimize indoor air quality as a novel therapeutic approach to improving COPD health outcomes.
indoor air; chronic obstructive pulmonary disease; particulate matter; nitrogen dioxide; exacerbations
To develop a propensity score-based risk adjustment method to estimate the performance of 20 physician groups and to compare performance rankings using our method to a standard hierarchical regression-based risk adjustment method.
Data Sources/Study Setting
Mailed survey of patients from 20 California physician groups between July 1998 and February 1999.
A cross-sectional analysis of physician group performance using patient satisfaction with asthma care. We compared the performance of the 20 physician groups using a novel propensity score-based risk adjustment method. More specifically, by using a multinomial logistic regression model we estimated for each patient the propensity scores, or probabilities, of having been treated by each of the 20 physician groups. To adjust for different distributions of characteristics across groups, patients cared for by a given group were first stratified into five strata based on their propensity of being in that group. Then, strata-specific performance was combined across the five strata. We compared our propensity score method to hierarchical model-based risk adjustment without using propensity scores. The impact of different risk-adjustment methods on performance was measured in terms of percentage changes in absolute and quintile ranking (AR, QR), and weighted κ of agreement on QR.
The propensity score-based risk adjustment method balanced the distributions of all covariates among the 20 physician groups, providing evidence for validity. The propensity score-based method and the hierarchical model-based method without propensity scores provided substantially different rankings (75 percent of groups differed in AR, 50 percent differed in QR, weighted κ=0.69).
We developed and tested a propensity score method for profiling multiple physician groups. We found that our method could balance the distributions of covariates across groups and yielded substantially different profiles compared with conventional methods. Propensity score-based risk adjustment should be considered in studies examining quality comparisons.
Physician group; profiling; propensity score; regression-to-the-mean; risk adjustment
Both being overweight and exposure to indoor pollutants, which have been associated with worse health of asthmatic patients, are common in urban minority populations. Whether being overweight is a risk factor for the effects of indoor pollutant exposure on asthma health is unknown.
We sought to examine the effect of weight on the relationship between indoor pollutant exposure and asthma health in urban minority children.
One hundred forty-eight children (age, 5–17 years) with persistent asthma were followed for 1 year. Asthma symptoms, health care use, lung function, pulmonary inflammation, and indoor pollutants were assessed every 3 months. Weight category was based on body mass index percentile.
Participants were predominantly African American (91%) and had public health insurance (85%). Four percent were underweight, 52% were normal weight, 16% were overweight, and 28% were obese. Overweight or obese participants had more symptoms associated with exposure to fine particulate matter measuring less than 2.5 μm in diameter (PM2.5) than normal-weight participants across a range of asthma symptoms. Overweight or obese participants also had more asthma symptoms associated with nitrogen dioxide (NO2) exposure than normal-weight participants, although this was not observed across all types of asthma symptoms. Weight did not affect the relationship between exposure to coarse particulate matter measuring between 2.5 and 10 μm in diameter and asthma symptoms. Relationships between indoor pollutant exposure and health care use, lung function, or pulmonary inflammation did not differ by weight.
Being overweight or obese can increase susceptibility to indoor PM2.5 and NO2 in urban children with asthma. Interventions aimed at weight loss might reduce asthma symptom responses to PM2.5 and NO2, and interventions aimed at reducing indoor pollutant levels might be particularly beneficial in overweight children.
Asthma; overweight; obesity; indoor pollutants childhood asthma; inner-city asthma
It is estimated that up to half of the world’s population burns biomass fuel (wood, crop residues, animal dung and coal) for indoor uses such as cooking, lighting and heating. As a result, a large proportion of women and children are exposed to high levels of household air pollution (HAP). The short and long term effects of these exposures on the respiratory health of this population are not clearly understood. On May 9–11, 2011 NIH held an international workshop on the "Health Burden of Indoor Air Pollution on Women and Children," in Arlington, VA. To gather information on the knowledge base on this topic and identify research gaps, ahead of the meeting we conducted a literature search using PubMed to identify publications that related to HAP, asthma, and chronic obstructive pulmonary disease (COPD). Abstracts were all analyzed and we report on those considered by the respiratory sub study group at the meeting to be most relevant to the field. Many of the studies published are symptom-based studies (as opposed to objective measures of lung function or clinical examination etc.) and measurement of HAP was not done. Many found some association between indoor exposures to biomass smoke as assessed by stove type (e.g., open fire vs. liquid propane gas) and respiratory symptoms such as wheeze and cough. Among the studies that examined objective measures (e.g. spirometry) as a health outcome, the data supporting an association between biomass smoke exposure and COPD in adult women are fairly robust, but the findings for asthma are mixed. If an association was observed between the exposures and lung function, most data seemed to demonstrate mild to moderate reductions in lung function, the pathophysiological mechanisms of which need to be investigated. In the end, the group identified a series of scientific gaps and opportunities for research that need to be addressed to better understand the respiratory effects of exposure to indoor burning of the different forms of biomass fuels.
Biomass smoke; cooking fuel smoke; Indoor air pollution; COPD; asthma
Although population differences in gene expression have been established, the impact on differential gene expression studies in large populations is not well understood. We describe the effect of self-reported race on a gene expression study of lung function in asthma. We generated gene expression profiles for 254 young adults (205 non-Hispanic whites and 49 African Americans) with asthma on whom concurrent total RNA derived from peripheral blood CD4+ lymphocytes and lung function measurements were obtained. We identified four principal components that explained 62% of the variance in gene expression. The dominant principal component, which explained 29% of the total variance in gene expression, was strongly associated with self-identified race (P<10−16). The impact of these racial differences was observed when we performed differential gene expression analysis of lung function. Using multivariate linear models, we tested whether gene expression was associated with a quantitative measure of lung function: pre-bronchodilator forced expiratory volume in one second (FEV1). Though unadjusted linear models of FEV1 identified several genes strongly correlated with lung function, these correlations were due to racial differences in the distribution of both FEV1 and gene expression, and were no longer statistically significant following adjustment for self-identified race. These results suggest that self-identified race is a critical confounding covariate in epidemiologic studies of gene expression and that, similar to genetic studies, careful consideration of self-identified race in gene expression profiling studies is needed to avoid spurious association.
ancestry; gene expression; population stratification; self-identified race
The inner-city pediatric population in the United States has a disproportionate burden of asthma. Recent attention has focused on the immunomodulatory role of vitamin D, which may be protective against disease morbidity. As the primary determinant of vitamin D status in humans is exposure to sunlight, we aimed to determine if 25-OH vitamin D levels in urban preschool children with asthma were low, influenced by time spent outdoors, and associated with asthma morbidity.
Serum 25-OH vitamin D levels were measured at baseline in a cohort of 121 inner-city children ages 2–6 years with asthma in Baltimore, MD. Participants were followed longitudinally at 3 and 6 months to assess time spent outdoors, asthma symptoms through questionnaires and daily diaries, and allergic markers.
In a predominantly black population of preschool children, the median 25-OH vitamin D level was 28 ng/mL (IQR 21.2-36.9), with 54% of the children below the traditionally sufficient level of 30 ng/mL and 7.4% in the range associated with risk of rickets (< 15 ng/mL). The median time spent outdoors was 3 hours/day (IQR 2–4), and greater time spent outdoors was not associated with higher vitamin D levels. 25-OH vitamin D did not show seasonal variation in our cohort (p = 0.66). Lower 25-OH levels were correlated with higher IgE levels.
Urban African-American preschool children with asthma have high rates of vitamin D insufficiency, and increased outdoor exposure is unlikely to correct these low 25-OH vitamin D levels. Repletion in this population may require dietary supplementation.
Asthma; Vitamin D; Outdoor; Ultraviolet; Exposure
William Martin and colleagues report on their stakeholder meetings that reviewed the health risks of household air pollution and cookstoves, and identified research priorities in seven key areas.
Please see later in the article for the Editors' Summary
Staphylococcus aureus in home environments may serve as a reservoir for human colonization, making sampling of indoor surfaces relevant to exposure assessment. Using laboratory experiments and application to homes of asthmatic children in Barbados, we characterize microbiological methods adapted for settings with transportation delays between sampling and initiation of culture.
Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies (GWAS) of asthma in 5,416 asthma cases representing European Americans, African Americans/African Caribbeans, and Latinos, and replicated five regions among the most significant signals in 12,649 individuals from the same ethnic groups. Four were at previously reported loci on 17q21, and near the IL1RL1, TSLP, and IL33, genes, but we report for the first time that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a novel association with asthma in the PYHIN1, gene that was specific to individuals of African descent (p=3.9×10−9). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma.
According to National Institutes of Health (NIH) guidelines, asthma control and severity are unique constructs. Little is known about how asthma control and severity are distinguished by pediatricians and if they influence treatment recommendations.
We conducted a random-sample survey of 500 pediatricians using patient vignettes with different asthma status indicators (recent hospitalization, parental report of bother from asthma, frequent symptoms, parental report of worsening asthma, and wheeze during physical exam) and a visual analog scale (VAS) to rate control and severity. Regression models assessed the independent effects of these indicators on asthma control and severity ratings, and the effects of these ratings on treatment recommendations.
A total of 270 respondents provided usable data. Compared to patients with well-controlled asthma: (1) medication intensity influenced only severity ratings; (2) frequent symptoms and recent hospitalization influenced control and severity ratings; (3) wheeze and bother influenced control ratings only (p<0.001 for all comparisons); (4) a report of worse asthma did not significantly affect any ratings (p>0.2). Poorer VAS control ratings were associated with recommendations to step-up treatment (odds ratio [OR] 2.61, 95% confidence interval [CI], 2.2–3.1, p<0.001), but more severe VAS ratings were not (OR 1.02, 95% CI, 0.9–1.2, p=0.8). Recommendations to step-down treatment were associated with poorer VAS control ratings (OR 0.70, 95% CI, 0.6–0.8, p<0.001) and more severe VAS ratings (OR 0.82, 95% CI, 0.7–0.9, p<0.001).
Pediatricians who step-up asthma treatment base their assessments on asthma control, while assessments of both control and severity factor into their decision to step-down asthma therapy.
Genome-wide association studies of human gene expression promise to identify functional regulatory genetic variation that contributes to phenotypic diversity. However, it is unclear how useful this approach will be for the identification of disease-susceptibility variants. We generated gene expression profiles for 22 184 mRNA transcripts using RNA derived from peripheral blood CD4+ lymphocytes, and genome-wide genotype data for 516 512 autosomal markers in 200 subjects. We screened for cis-acting variants by testing variants mapping within 50 kb of expressed transcripts for association with transcript abundance using generalized linear models. Significant associations were identified for 1585 genes at a false discovery rate of 0.05 (corresponding to P-values ranging from 1 × 10−91 to 7 × 10−4). Importantly, we identified evidence of regulatory variation for 119 previously mapped disease genes, including 24 examples where the variant with the strongest evidence of disease-association demonstrates strong association with specific transcript abundance. The prevalence of cis-acting variants among disease-associated genes was 63% higher than the genome-wide rate in our data set (P = 6.41 × 10−6), and although many of the implicated loci were associated with immune-related diseases (including asthma, connective tissue disorders and inflammatory bowel disease), associations with genes implicated in non-immune-related diseases including lipid profiles, anthropomorphic measurements, cancer and neurologic disease were also observed. Genetic variants that confer inter-individual differences in gene expression represent an important subset of variants that contribute to disease susceptibility. Population-based integrative genetic approaches can help identify such variation and enhance our understanding of the genetic basis of complex traits.
We sought to evaluate factors associated with choices about provided care for patients with septic shock, including the use of drotrecogin alfa (activated) [DAA].
Materials and Methods
We administered a mail-based survey to a random sample of intensivists. Study vignettes presented patients with septic shock with identical severity of illness scores but different ages, body mass indices and co-morbidities. Respondents estimated outcomes and selected care beyond standardized initial care (e.g. antibiotics) for each hypothetical patient.
For the majority of vignettes (99.1%), respondents added care, most commonly low tidal volume ventilation (87.6%) and enteral nutrition (73.3%). Choosing to administer DAA was not associated with predictions about mortality or bleeding. Vignettes with early-stage lung cancer were less likely to receive DAA. Time since medical school graduation was also associated with lower odds of selecting DAA. The majority of respondents (52.6%) chose identical care for all four completed vignettes.
There was wide variability in the therapeutic choices of respondents. The use of DAA was not associated with perceived risk of mortality or bleeding, as recommended by consensus guidelines. Physicians appear to base treatment decisions in septic shock on a consistent pattern of practice rather than estimates of patient outcome.
Sepsis; septic shock; variation in care; drotrecogin alfa activated; acute lung injury
High frequency chest wall oscillation (HFCWO) is used for airway mucus clearance. The objective of this study was to evaluate the use of HFCWO early in the treatment of adults hospitalized for acute asthma or chronic obstructive pulmonary disease (COPD).
Randomized, multi-center, double-masked phase II clinical trial of active or sham treatment initiated within 24 hours of hospital admission for acute asthma or COPD at four academic medical centers. Patients received active or sham treatment for 15 minutes three times a day for four treatments. Medical management was standardized across groups. The primary outcomes were patient adherence to therapy after four treatments (minutes used/60 minutes prescribed) and satisfaction. Secondary outcomes included change in Borg dyspnea score (≥ 1 unit indicates a clinically significant change), spontaneously expectorated sputum volume, and forced expired volume in 1 second.
Fifty-two participants were randomized to active (n = 25) or sham (n = 27) treatment. Patient adherence was similarly high in both groups (91% vs. 93%; p = 0.70). Patient satisfaction was also similarly high in both groups. After four treatments, a higher proportion of patients in the active treatment group had a clinically significant improvement in dyspnea (70.8% vs. 42.3%, p = 0.04). There were no significant differences in other secondary outcomes.
HFCWO is well tolerated in adults hospitalized for acute asthma or COPD and significantly improves dyspnea. The high levels of patient satisfaction in both treatment groups justify the need for sham controls when evaluating the use of HFCWO on patient-reported outcomes. Additional studies are needed to more fully evaluate the role of HFCWO in improving in-hospital and post-discharge outcomes in this population.
asthma; chronic obstructive pulmonary disease; high frequency chest wall oscillation; airway mucus clearance