Trends in use of primary prophylactic colony stimulating factors and neutropenia-related hospitalization in commercially insured patients receiving myelosuppressive chemotherapy in the United States: 2005-2017.

PURPOSE: Describe temporal changes in use of myelosuppressive chemotherapy, primary prophylactic colony-stimulating factor, and neutropenia-related hospitalization, in commercially insured patients. METHODS: Using a large commercial administrative database, we identified annual cohorts of adult patients diagnosed with breast or lung cancer, or non-Hodgkin lymphoma and initiating myelosuppressive chemotherapy during 2005-2017. We described yearly changes in proportions of myelosuppressive chemotherapy by febrile neutropenia risk category (high, intermediate, unclassified) and proportion of prophylactic colony-stimulating factor use and unadjusted incidence of neutropenia-related hospitalization in the first cycle of myelosuppressive chemotherapy. RESULTS: Annual cohorts included 4383-5888 eligible patients during 2005-2017. The proportion of eligible patients aged ≥ 65 years increased from 26.0% in 2005 to 58.2% in 2017. Myelosuppressive chemotherapy use with regimens with high risk for febrile neutropenia increased from 15.1% in 2005 to 31.0% in 2017; and regimens with intermediate risk for febrile neutropenia decreased from 63.7% to 48.1% in 2017. Prophylactic colony-stimulating factor use increased from 41.6% in 2005 to 54.3% in 2017. Crude incidence of neutropenia-related hospitalization for all cancers increased from 2.0% to 3.1%, with a substantial increase in neutropenia-related hospitalization observed among non-Hodgkin lymphoma patients (2.8% to 8.5%) during 2005-2017. CONCLUSION: Among adult patients with breast and lung cancer, and non-Hodgkin lymphoma receiving myelosuppressive chemotherapy, use of regimens with high risk for febrile neutropenia increased, as did the use of prophylactic colony-stimulating factors after 2005. Incidence of neutropenia-related hospitalization increased slightly, particularly among non-Hodgkin lymphoma patients. Further studies are required to understand this increasing trend of neutropenia-related hospitalization, changing patient-level risk factors, and febrile neutropenia management.

Endotoxin Exposure: Predictors and Prevalence of Associated Asthma Outcomes in the United States.

RATIONALE: Inhaled endotoxin induces airway inflammation and is an established risk factor for asthma. The 2005-2006 National Health and Nutrition Examination Survey included measures of endotoxin and allergens in homes as well as specific IgE to inhalant allergens. OBJECTIVES: To understand the relationships between endotoxin exposure, asthma outcomes, and sensitization status for 15 aeroallergens in a nationally representative sample. METHODS: Participants were administered questionnaires in their homes. Reservoir dust was vacuum sampled to generate composite bedding and bedroom floor samples. We analyzed 7,450 National Health and Nutrition Examination Survey dust and quality assurance samples for their endotoxin content using extreme quality assurance measures. Data for 6,963 subjects were available, making this the largest study of endotoxin exposure to date. Log-transformed endotoxin concentrations were analyzed using logistic models and forward stepwise linear regression. Analyses were weighted to provide national prevalence estimates and unbiased variances. MEASUREMENTS AND MAIN RESULTS: Endotoxin exposure was significantly associated with wheeze in the past 12 months, wheeze during exercise, doctor and/or emergency room visits for wheeze, and use of prescription medications for wheeze. Models adjusted for age, sex, race and/or ethnicity, and poverty-to-income ratio and stratified by allergy status showed that these relationships were not dependent upon sensitization status but were worsened among those living in poverty. Significant predictors of higher endotoxin exposures were lower family income; Hispanic ethnicity; participant age; dog(s), cat(s), cockroaches, and/or smoker(s) in the home; and carpeted floors. CONCLUSIONS: In this U.S. nationwide representative sample, higher endotoxin exposure was significantly associated with measures of wheeze, with no observed protective effect regardless of sensitization status.

Prevalence of allergic sensitization in the United States: results from the National Health and Nutrition Examination Survey (NHANES) 2005-2006.

BACKGROUND: Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005-2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. OBJECTIVE: We investigated clustering, sociodemographic, and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. METHODS: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Participants aged 1 year or older (n = 9440) were tested for serum specific IgEs (sIgEs) to inhalant and food allergens; participants 6 years or older were tested for 19 sIgEs, and children aged 1 to 5 years were tested for 9 sIgEs. Serum samples were analyzed by using the ImmunoCAP System. Information on demographics and participants' characteristics was collected by means of questionnaire. RESULTS: Of the study population aged 6 years and older, 44.6% had detectable sIgEs, whereas 36.2% of children aged 1 to 5 years were sensitized to 1 or more allergens. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling young age, male sex, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. CONCLUSIONS: The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs based on sociodemographic and regional factors. Biological cross-reactivity might be an important but not the sole contributor to the clustering of allergen-specific IgEs.

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.

Relationship between serum cholesterol and indices of erythrocytes and platelets in the US population.

Whereas dyslipidemia has been associated with leukocytosis, the relationship between serum cholesterol and other hematopoietic lineages is poorly defined. Erythrocytes and platelets, anucleate cells relegated to nonspecific diffusional exchange of cholesterol with serum, have been proposed to have a distinct relationship to cholesterol from leukocytes. We examined the relationship between serum cholesterol and circulating erythrocyte/platelet indices in 4,469 adult participants of the National Health and Nutrition Examination Survey (NHANES) 2005-2006. In linear regression analyses, serum non-high density lipoprotein-cholesterol (non-HDL-C) was positively associated with mean erythrocyte number, hematocrit, hemoglobin concentration, platelet count, and platelet crit independently of age, gender, race/ethnicity, smoking, body mass index, serum folate, and C-reactive protein. The magnitude of the relationship was most marked for platelets, with lowest versus highest non-HDL-C quartile subjects having geometric mean platelet counts of 258,000/µl versus 281,000/µl, respectively (adjusted model, P < 0.001 for trend). These associations persisted in a sensitivity analysis excluding several conditions that affect erythrocyte/platelet and/or serum cholesterol levels, and were also noted in an independent analysis of 5,318 participants from NHANES 2007-2008. As non-HDL-C, erythrocytes, and platelets all impact cardiovascular disease risk, there is a need for advancing understanding of the underlying interactions that govern levels of these three blood components.

Allergy-related outcomes in relation to serum IgE: results from the National Health and Nutrition Examination Survey 2005-2006.

BACKGROUND: The National Health and Nutrition Examination Survey (NHANES) 2005-2006 was the first population-based study to investigate levels of serum total and allergen-specific IgE in the general US population. OBJECTIVE: We estimated the prevalence of allergy-related outcomes and examined relationships between serum IgE levels and these outcomes in a representative sample of the US population. METHODS: Data for this cross-sectional analysis were obtained from NHANES 2005-2006. Study subjects aged 6 years and older (n = 8086) had blood taken for measurement of total IgE and 19 specific IgE levels against common aeroallergens, including Alternaria alternata, Aspergillus fumigatus, Bermuda grass, birch, oak, ragweed, Russian thistle, rye grass, cat dander, cockroach, dog dander, dust mite (Dermatophagoides farinae and Dermatophagoides pteronyssinus), mouse and rat urine proteins, and selected foods (egg white, cow's milk, peanut, and shrimp). Serum samples were analyzed for total and allergen-specific IgE by using the Pharmacia CAP System. Information on allergy-related outcomes and demographics was collected by questionnaire. RESULTS: In NHANES 2005-2006, 6.6% reported current hay fever, and 23.5% had current allergies. Allergy-related outcomes increased with increasing total IgE levels (adjusted odds ratios for a 10-fold increase in total IgE level of 1.86 [95% CI, 1.44-2.41] for hay fever and 1.64 [95% CI, 1.41-1.91] for allergies). Increased levels of plant-, pet-, and mold-specific IgE contributed independently to allergy-related symptoms. The greatest increase in odds was observed for hay fever and plant-specific IgE (adjusted odds ratio, 4.75; 95% CI, 3.83-5.88). CONCLUSION: In the US population self-reported allergy symptoms are most consistently associated with increased levels of plant-, pet-, and mold-specific IgE.

Questionnaire predictors of atopy in a US population sample: findings from the National Health and Nutrition Examination Survey, 2005-2006.

Allergic conditions and biochemical measures are both used to characterize atopy. To assess questionnaires' ability to predict biochemical measures of atopy, the authors used data on 5 allergic conditions (allergy, hay fever, eczema, rhinitis, and itchy rash) and serum-specific immunoglobulin E (IgE) levels from the 2005-2006 National Health and Nutrition Examination Survey. Atopy was defined as 1 or more positive specific IgEs (≥0.35 kU/L). Questionnaire responses were assessed for sensitivity, specificity, and positive and negative predictive values for atopy. In this population-based US sample, 44% of participants were specific IgE-positive and 53% reported at least 1 allergic condition. Discordance between atopy and allergic conditions was considerable; 37% of persons with atopy reported no allergic condition, and 48% of persons who reported an allergic condition were not atopic. Thus, no combination of self-reported allergic conditions achieved both high sensitivity and high specificity for IgE. The positive predictive value of reported allergic conditions for atopy ranged from 50% for eczema to 72% for hay fever, while the negative predictive value ranged from 57% for eczema to 65% for any condition. Given the high proportion of asymptomatic participants who were specific IgE-positive and persons who reported allergic conditions but were specific IgE-negative, it is unlikely that questionnaires will ever capture the same participants as those found to be atopic by biochemical measures.

National prevalence and risk factors for food allergy and relationship to asthma: results from the National Health and Nutrition Examination Survey 2005-2006.

BACKGROUND: The national prevalence and patterns of food allergy (FA) in the United States are not well understood. OBJECTIVE: We developed nationally representative estimates of the prevalence of and demographic risk factors for FA and investigated associations of FA with asthma, hay fever, and eczema. METHODS: A total of 8203 participants in the National Health and Nutrition Examination Survey 2005-2006 had food-specific serum IgE measured to peanut, cow's milk, egg white, and shrimp. Food-specific IgE and age-based criteria were used to define likely FA (LFA), possible FA, and unlikely FA and to develop estimates of clinical FA. Self-reported data were used to evaluate demographic risk factors and associations with asthma and related conditions. RESULTS: In the United States, the estimated prevalence of clinical FA was 2.5% (peanut, 1.3%; milk, 0.4%; egg, 0.2%; shrimp, 1.0%; not mutually exclusive). Risk of possible FA/LFA was increased in non-Hispanic blacks (odds ratio, 3.06; 95% CI, 2.14-4.36), males (1.87; 1.32-2.66), and children (2.04; 1.42-2.93). Study participants with doctor-diagnosed asthma (vs no asthma) exhibited increased risk of all measures of food sensitization. Moreover, in those with LFA, the adjusted odds ratio for current asthma (3.8; 1.5-10.7) and an emergency department visit for asthma in the past year (6.9; 2.4-19.7) were both notably increased. CONCLUSION: Population-based serologic data on 4 foods indicate an estimated 2.5% of the US population has FA, and increased risk was found for black subjects, male subjects, and children. In addition, FA could be an under-recognized risk factor for problematic asthma.

Occurrence and Management of Thrombocytopenia in Metastatic Colorectal Cancer Patients Receiving Chemotherapy: Secondary Analysis of Data From Prospective Clinical Trials.

INTRODUCTION: Chemotherapy-induced thrombocytopenia (CIT) contributes to treatment dose delay and/or modification, often resulting in poorer survival and disease progression. We explored the incidence and clinical consequences of CIT among metastatic colorectal cancer (mCRC) patients. MATERIALS AND METHODS: Data from two prospective randomized phase 3 trials of mCRC patients receiving either first-line FOLFOX4 (fluorouracil, leucovorin, oxaliplatin) or second-line FOLFIRI (fluorouracil, leucovorin, irinotecan) were analyzed. Thrombocytopenia was defined by platelet count < 100 × 109/L (further categorized by grade) and by recorded adverse events (AEs). Co-occurrence of anemia (hemoglobin < 12 g/dL) and neutropenia (neutrophil count < 2 × 109/L) and clinical consequences of CIT were also evaluated. RESULTS: Among 1078 mCRC patients in the FOLFOX4 study, cumulative incidence of CIT based on platelet count was 37% (grade 3, 2%; grade 4, 1%) during an average 8 months' follow-up. Neutropenia or anemia were absent in 44% of CIT episodes; 62% of CIT AEs led to chemotherapy dose delay, change, and/or discontinuation. Among 1067 mCRC patients in the FOLFIRI study, cumulative incidence of CIT based on platelet count was 4% (grade 3, < 1%; grade 4, 0) during an average 4 months' follow-up. Neutropenia or anemia were absent in 22% of CIT episodes; 32% of CIT AEs led to chemotherapy dose delay, change, and/or discontinuation. With both regimens, transfusions and hospitalizations after CIT AEs were rare (< 3%). CONCLUSION: CIT was common among mCRC patients receiving the FOLFOX4 regimen. The most frequent consequence of CIT was a delay in chemotherapy, highlighting the unmet need in CIT management.

Novel relationship of serum cholesterol with asthma and wheeze in the United States.

BACKGROUND: Cholesterol exerts complex effects on inflammation. There has been little investigation of whether serum cholesterol is associated with asthma, an inflammatory airways disease with great public health impact. OBJECTIVE: To determine relationships between levels of 3 serum cholesterol measures (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], and non-HDL-C) and asthma/wheeze in a sample representative of the US population. METHODS: Cross-sectional study of 7005 participants age >or=6 years from the 2005 to 2006 National Health and Nutrition Examination Survey. RESULTS: Serum TC and non-HDL-C were lower in patients with current asthma than in subjects without current asthma in the overall population (TC, 188.5 vs 192.2 mg/dL; non-HDL-C, 133.9 vs 137.7 mg/dL; P < .05 for both), whereas HDL-C was not different. Adjusted odds ratios (ORs) from multivariate logistic regression per 1-SD increase of TC and non-HDL-C for current asthma were 0.92 (95% CI, 0.86-0.98) and 0.91 (95% CI, 0.85-0.98), respectively. On racial/ethnic stratification, these relationships reflect marked reductions unique to Mexican Americans (MAs; TC, 171.4 vs 189.3 mg/dL; P < .001; OR, 0.62; 95% CI, 0.48-0.80; non-HDL-C, 119.8 vs 137.9 mg/dL; P < .001; OR, 0.62; 95% CI, 0.48-0.79). Among MAs, the adjusted OR for wheeze requiring medical attention was 0.57 (95% CI, 0.43-0.75) for TC and 0.53 (95% CI, 0.33-0.85) for non-HDL-C. Relationships between cholesterol and asthma/wheeze were independent of body mass index and serum C-reactive protein, and similar between atopic and nonatopic participants. CONCLUSION: Serum TC and non-HDL-C are inversely related to asthma in the US population, chiefly reflecting a relationship among MAs.

National prevalence and exposure risk for cockroach allergen in U.S. households.

UNLABELLED: We characterized the prevalence of cockroach allergen exposure in a nationally representative sample of U.S. homes and assessed risk factors for elevated concentrations. DESIGN: We used data from the National Survey of Lead and Allergens in Housing, a population-based cross-sectional survey. PARTICIPANTS: Participants were residents of 831 U.S. homes in the survey. EVALUATIONS/MEASUREMENTS: We analyzed allergen, questionnaire, and observational data of 831 U.S. homes. RESULTS: Cockroach allergen (Bla g 1) concentrations exceed 2.0 U/g, a level associated with allergic sensitization, in 11% of U.S. living room floors and 13% of kitchen floors. Concentrations exceed 8.0 U/g, a level associated with asthma morbidity, in 3% of living room floors and 10% of kitchen floors. Elevated concentrations were observed in high-rise apartments, urban settings, pre-1940 constructions, and households with incomes < $20,000. Odds of having concentrations > 8.0 U/g were greatest when roach problems were reported or observed and increased with the number of cockroaches observed and with indications of recent cockroach activity. CONCLUSIONS: Household cockroach allergen exposure is characterized in a nationally representative context. The allergen is prevalent in many settings, at levels that may contribute to allergic sensitization and asthma morbidity. RELEVANCE TO CLINICAL OR PROFESSIONAL PRACTICE: Likelihood of exposure can be assessed by consideration of demographic and household determinants.

Phthalate exposure and allergy in the U.S. population: results from NHANES 2005-2006.

BACKGROUND: Environmental exposures to phthalates, particularly high-molecular-weight (HMW) phthalates, are suspected to contribute to allergy. OBJECTIVE: We assessed whether phthalate metabolites are associated with allergic symptoms and sensitization in a large nationally representative sample. METHODS: We used data on urinary phthalate metabolites and allergic symptoms (hay fever, rhinitis, allergy, wheeze, asthma) and sensitization from participants ≥ 6 years of age in the National Health and Nutrition Examination Survey (NHANES) 2005-2006. Allergen sensitization was defined as a positive response to at least one of 19 specific IgE antigens (≥ 0.35 kU/L). Odds ratios (ORs) per one log10 unit change in phthalate concentration were estimated using logistic regression adjusting for age, race, body mass index, gender, creatinine, and cotinine. Separate analyses were conducted for children (6-17 years of age) and adults. RESULTS: The HMW phthalate metabolite monobenzyl phthalate (MBzP) was the only metabolite positively associated with current allergic symptoms in adults (wheeze, asthma, hay fever, and rhinitis). Mono-(3-carboxypropyl) phthalate and the sum of diethylhexyl phthalate metabolites (both representing HMW phthalate exposures) were positively associated with allergic sensitization in adults. Conversely, in children, HMW phthalate metabolites were inversely associated with asthma and hay fever. Of the low-molecular-weight phthalate metabolites, monoethyl phthalate was inversely associated with allergic sensitization in adults (OR = 0.79; 95% CI: 0.70, 0.90). CONCLUSION: In this cross-sectional analysis of a nationally representative sample, HMW phthalate metabolites, particularly MBzP, were positively associated with allergic symptoms and sensitization in adults, but there was no strong evidence for associations between phthalates and allergy in children 6-17 years of age.

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.

Exposure to mouse allergen in U.S. homes associated with asthma symptoms.

BACKGROUND: Most studies investigating the role of residential mouse allergen exposures in asthma have focused on inner-city populations. OBJECTIVE: We examined whether elevated mouse allergen levels were associated with occupants' asthma status in a nationally representative sample of U.S. households. METHODS: Data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed 831 housing units inhabited by 2,456 individuals in 75 different locations throughout the United States. The survey obtained information on demographics, household characteristics, and occupants' health status by questionnaire and environmental observations. We used a polyclonal immunoassay to assess concentrations of mouse urinary protein (MUP) in vacuumed dust collected from various indoor sites. RESULTS: Of the surveyed homes, 82% had detectable levels of MUP, and in 35% of the homes, MUP concentrations exceeded 1.6 microg/g, a level that has been associated with increased mouse allergen sensitization rates. Current asthma, defined as having doctor-diagnosed asthma and asthma symptoms in the preceding 12 months, was positively associated with increased MUP levels. The observed association was modified by atopic status; in allergic individuals, elevated MUP levels (>1.6 microg/g) increased the odds of having asthma symptoms [adjusted OR=1.93; 95% confidence interval (CI), 1.14-3.27], but we found no association in those who did not report allergies (adjusted OR=0.69; 95% CI, 0.33-1.44). CONCLUSIONS: In allergic asthma, residential mouse allergen exposure is an important risk factor for asthma morbidity.

Exposure to Alternaria alternata in US homes is associated with asthma symptoms.

BACKGROUND: Exposure to the fungus Alternaria alternata is a risk factor for asthma. Few studies have examined Alternaria exposures in indoor environments. OBJECTIVE: We examined whether exposure to A alternata in US homes was associated with asthma-related outcomes. METHODS: The data for this study were collected as part of the National Survey of Lead and Allergens in Housing. This cross-sectional study surveyed a nationally representative sample of 831 housing units inhabited by 2456 individuals in 75 different locations throughout the United States. An interviewer-administered questionnaire obtained information on demographics, household characteristics, and occupants' health status. Exposure to A alternata was assessed by measuring concentrations of A alternata antigens in vacuumed dust samples using a polyclonal anti-A alternata antibody assay. Dust samples were collected from a bed, a sofa, or a chair, and from bedroom, living room, and kitchen floors. RESULTS: Lifetime prevalence of doctor-diagnosed asthma was 11.2%, and 6.9% of the study subjects reported active asthma symptoms in the past 12 months. The prevalence of current symptomatic asthma increased with increasing Alternaria concentrations in US homes; higher levels of A alternata antigens increased the odds of having asthma symptoms in the past year (relative to the lowest tertile, adjusted odds ratio was 1.52, 95% CI, 0.90-2.55 for the 2nd tertile; and 1.84, 95% CI, 1.18-2.85 for the 3rd tertile). CONCLUSION: Exposure to A alternata in US homes is associated with active asthma symptoms. CLINICAL IMPLICATIONS: Measures that reduce indoor exposure to A alternata may help control asthma exacerbations.

National prevalence and exposure risk for mouse allergen in US households.

BACKGROUND: Exposure to mouse allergen is a known cause of asthma in occupational settings and exhibits high prevalence and association with allergic sensitization in inner-city home environments. It has never been characterized on a nationally representative scale. OBJECTIVE: This study was designed to characterize mouse allergen prevalence in a representative sample of US homes and to assess risk factors for increased concentrations. METHODS: Allergen, questionnaire, and observational data were analyzed from the first National Survey of Lead and Allergens in Housing, a cross-sectional survey of 831 US housing units. Allergen levels were characterized and related to demographic factors and household characteristics. RESULTS: Detectable levels of mouse allergen (Mus m 1) exist in 82% of US homes. Kitchen floor concentrations exceed 1.6 microg/g, a level associated with increased sensitization rates, in 22% of homes. Increased concentrations (>1.6 microg/g) were observed in high-rise apartments and mobile homes, older homes, and low-income homes. Odds of having increased concentrations were increased when rodent (odds ratio [OR], 3.38) or cockroach (OR, 1.81) problems were reported and when floor mopping (OR, 2.17) was performed instead of vacuuming. CONCLUSIONS: Household mouse allergen is widespread in many settings at levels that might contribute to asthma morbidity. The likelihood of exposure can be assessed by consideration of demographic and household determinants.