How and by whom care is delivered influences anti-inflammatory use in asthma: Results of a national population survey

BACKGROUND: Studies examining the influence of provider behavior and patterns of care delivery on the use of anti-inflammatory asthma therapy have been limited to selected populations or have been unable to assess the appropriateness of therapy for individuals. We have previously reported the influence of sociodemographic variables and asthma severity on reported use of asthma medications in the United States. OBJECTIVE: We sought to examine the influence of patterns of care delivery and clinician behavioral factors on the use of anti-inflammatory medication by patients with asthma. METHODS: We performed a cross-sectional national random digit dial household telephone survey in 1998 of adult patients and parents of children with current asthma. Respondents were classified as having current asthma if they had a physician's diagnosis of asthma and were either taking medication for asthma or had asthma symptoms during the past year. RESULTS: One or more persons met the study criteria for current asthma in 3273 (7.8%) households in which a screening questionnaire was completed. Of the 2509 persons (721 children <16 years of age) with current asthma interviewed, 507 (20.1%) reported current use of anti-inflammatory medication. In a multiple logistic regression model controlling for asthma symptoms, reported anti-inflammatory use was significantly associated with patients reporting their physician having an excellent ability to explain asthma management (odds ratio [OR], 1.47; 95% CI, 1.09-1.98), scheduling regular visits to a physician for asthma (OR, 1.30; 95% CI, 1.02-1.64), having a written asthma action plan (OR, 1.63; 95% CI, 1.29-2.06), and being of white, non-Hispanic ethnicity (OR, 1.53; 95% CI, 1.19-1.98), along with markers of greater asthma morbidity, missing 6 or more days from work or school in the past year (OR, 1.29; 95% CI, 1.01-1.65), and hospitalization for asthma in the past year (OR, 1.74; 95% CI, 1.19-2.53). Anti-inflammatory use was less likely to be reported with younger age (OR, 0.82; 95% CI, 0.73-0.94), lower long-term asthma symptom burden (OR, 0.82; 95% CI, 0.71-0.94), use of 4 or fewer reliever inhaler canisters in the past year (OR, 0.50; 95% CI, 0.43-0.58), and smoking (OR, 0.50; 95% CI, 0.37-0.68). CONCLUSION: How asthma care is delivered influences the use of anti-inflammatory medication. Strategies to increase regular evaluation by a physician interested in asthma, particularly for minority patients, and to increase a physician's ability to communicate asthma management to patients might improve use of anti-inflammatory therapy among patients with asthma.     

The utility of the Health Plan Employer Data and Information Set (HEDIS) asthma measure to predict asthma-related outcomes.

BACKGROUND: The Health Plan Employer Data and Information Set (HEDIS) measures are used extensively to measure quality of care. OBJECTIVE: To evaluate selected aspects of the HEDIS measure of appropriate use of asthma medications. METHODS: Claims data were analyzed for commercial health plan members who met HEDIS criteria for persistent asthma in 1999. The use of asthma medications was evaluated in the subsequent year with stratification by controller medication and a measure of adherence (days' supply). Multivariate logistic regressions were used to evaluate the association among long-term controller therapy for persistent asthma, adherence to therapy, and asthma-related hospitalizations or emergency department (ED) visits, controlling for demographic, preindex utilization, and other confounding characteristics. RESULTS: Of the 49,637 persistent asthma patients, approximately 35.7% were using 1 class of long-term controller medications, 18.4% were using more than 1 class, and 45.9% were not using such medication. More than 25% of the persistent asthma patients did not use any asthma medication in the subsequent year. Patients with low adherence to controller medication had a significantly higher risk (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.42-2.08) of ED visit or hospitalization relative to patients not using any controllers compared with persons with moderate (OR, 0.84; 95% CI, 0.57-1.23) or high (OR, 0.70; 95% CI, 0.34-1.44) adherence. Patients receiving a high days' supply of inhaled corticosteroids had the lowest risk of ED visit or hospitalization (OR, 0.37; 95% CI, 0.05-2.69). CONCLUSIONS: Our findings suggest that refinements to the HEDIS measure method for identifying patients with persistent asthma may be needed.     

Rhinitis therapy and the prevention of hospital care for asthma: a case-control study

BACKGROUND: Although clinical trials have demonstrated that rhinitis therapy improves subjective and objective measures of asthma, it is uncertain whether treatment of allergic rhinitis significantly affects the frequency of asthma exacerbations. OBJECTIVE: The objective of this study was to determine whether treatment with intranasal corticosteroids and/or second-generation antihistamines is associated with changes in rates of asthma exacerbations resulting in emergency room visits and/or hospitalizations in patients with asthma and allergic rhinitis. METHODS: This was a nested, case-control study. RESULTS: Treatment with either nasal corticosteroids or second-generation antihistamines was associated with a lower risk of asthma-related emergency room treatment and hospitalization (adjusted odds ratio [OR], 0.51; 95% CI, 0.34 to 0.77 and 0.34, 0.18 to 0.62, respectively). Patients who used nasal corticosteroids had a significantly lower risk of both asthma-related emergency room treatment and hospitalization (adjusted OR, 0.75; 95% CI, 0.62 to 0.91 and 0.56, 0.42 to 0.76, respectively), whereas there was a trend toward lower risk of emergency room treatment and hospitalization in patients who used second-generation antihistamines (adjusted OR, 0.88; 95% CI, 0.62 to 1.26 and 0.68, 0.40 to 1.14, respectively). Combined treatment with both medications was associated with a further lowering of the risk of both emergency room treatment and hospitalization (adjusted OR, 0.37; 95% CI, 0.19 to 0.73 and 0.22, 0.07 to 0.63). CONCLUSIONS: In patients with asthma, treatment of concomitant allergic rhinitis was associated with significant reductions in risk of emergency room treatment and hospitalization for asthma.     

Inhaled corticosteroids and allergy specialty care reduce emergency hospital use for asthma

BACKGROUND: The interrelationships between optimal inhaled corticosteroid (IC) therapy, allergy specialist care, and reduced emergency hospital care for asthma have not been well defined. OBJECTIVE: We sought to evaluate the independent effectiveness of various levels of IC dispensing and allergy specialist care in reducing subsequent emergency asthma hospital use. METHODS: Asthmatic patients (n = 9608) aged 3 to 64 years were identified from an electronic database of a large health maintenance organization. The outcome was any year 2000 asthma hospitalization or emergency department visit. The main predictors were at least one allergy department visit and the number of IC canisters dispensed in 1999. Analyses were adjusted for age, sex, insurance type, and asthma severity (1999 emergency asthma hospital use, beta-agonist use, and oral corticosteroid use). RESULTS: Dispensing of 7 or more canisters of ICs (odds ratio [OR], 0.64; 95% CI, 0.43-0.94) and allergy care (OR, 0.73; 95% CI, 0.55-0.97) were associated with reduced subsequent emergency asthma hospital use. More patients with allergy specialist care than those without such care received 7 or more dispensations of ICs (24.7% vs 8.3%, P <.001). When 7 or more dispensations of ICs and allergy specialist care were simultaneously included in an adjusted model, both ICs (OR, 0.68; 95% CI, 0.46-1.00) and allergy care (OR, 0.77; 95% CI, 0.58-1.02) were independently associated with a lower risk of year 2000 emergency asthma hospital care, although significance was borderline. CONCLUSION: Allergy care reduces emergency hospital use for asthma by increasing use of ICs but probably also has an independent effect.     

Caesarean delivery and risk of atopy and allergic disesase: meta-analyses

Background Studies of delivery by caesarean section (c‐section) and the offspring's risk of allergic diseases are of current interest due to concerns about the increased use of c‐section in many countries. However, previous studies have reported inconsistent findings. Objective We investigated whether delivery by c‐section is associated with an increased risk of atopy and allergic disease by reviewing the literature, performing a meta‐analysis, and assessing publication bias. Methods We used a systematic literature search of MEDLINE (1966 to May 2007). Six common allergic outcomes were included: food allergy/food atopy, inhalant atopy, eczema/atopic dermatitis, allergic rhinitis, asthma, and hospitalization for asthma. For each outcome a meta‐analysis was performed, where a summary odds ratio (OR) was calculated taking into account heterogeneity between the study‐specific relative risks. Publication bias was assessed using the funnel plot method. Results We identified 26 studies on delivery by c‐section and one or more of the six allergic outcomes. C‐section was associated with an increased summary OR of food allergy/food atopy (OR 1.32, 95% CI 1.12–1.55; six studies), allergic rhinitis (OR 1.23, 95% CI 1.12–1.35; seven studies), asthma (OR 1.18, 95% CI 1.05–1.32; 13 studies), and hospitalization for asthma (OR 1.21, 95% CI 1.12–1.31; seven studies), whereas there was no association with inhalant atopy (OR 1.06, 95% CI 0.82–1.38; four studies) and eczema/atopic dermatitis (OR 1.03, 95% CI 0.98–1.09; six studies). Funnel plots indicated that the association with food allergy/food atopy could be difficult to interpret due to publication bias. For each significant association with an allergic outcome, only 1–4% of cases were attributable to c‐section. Conclusion Delivery by c‐section is associated with a moderate risk increase for allergic rhinitis, asthma, hospitalization for asthma, and perhaps food allergy/food atopy, but not with inhalant atopy or atopic dermatitis. The increased use of c‐section during the last decades is unlikely to have contributed much to the allergy epidemic observed during the same period.     

Epidemiology of influenza-associated hospitalization in adults, Toronto, 2007/8

The purpose of this investigation was to identify when diagnostic testing and empirical antiviral therapy should be considered for adult patients requiring hospitalization during influenza seasons. During the 2007/8 influenza season, six acute care hospitals in the Greater Toronto Area participated in active surveillance for laboratory-confirmed influenza requiring hospitalization. Nasopharyngeal (NP) swabs were obtained from patients presenting with acute respiratory or cardiac illness, or with febrile illness without clear non-respiratory etiology. Predictors of influenza were analyzed by multivariable logistic regression analysis and likelihoods of influenza infection in various patient groups were calculated. Two hundred and eighty of 3,917 patients were found to have influenza. Thirty-five percent of patients with influenza presented with a triage temperature ≥38.0°C, 80% had respiratory symptoms in the emergency department, and 76% were ≥65 years old. Multivariable analysis revealed a triage temperature ≥38.0°C (odds ratio [OR] 3.1; 95% confidence interval [CI] 2.3–4.1), the presence of respiratory symptoms (OR 1.7; 95% CI 1.2–2.4), admission diagnosis of respiratory infection (OR 1.8; 95% CI 1.3–2.4), admission diagnosis of exacerbation of chronic obstructive pulmonary disease (COPD)/asthma or respiratory failure (OR 2.3; 95% CI 1.6–3.4), and admission in peak influenza weeks (OR 4.2; 95% CI 3.1–5.7) as independent predictors of influenza. The likelihood of influenza exceeded 15% in patients with respiratory infection or exacerbation of COPD/asthma if the triage temperature was ≥38.0°C or if they were admitted in the peak weeks during the influenza season. During influenza season, diagnostic testing and empiric antiviral therapy should be considered in patients requiring hospitalization if respiratory infection or exacerbation of COPD/asthma are suspected and if either the triage temperature is ≥38.0°C or admission is during the weeks of peak influenza activity.     

Childhood asthma hospitalization risk after cesarean delivery in former term and premature infants.

BACKGROUND: Cesarean delivery modifies infant gut bacterial flora composition, which may result in hindered tolerance to allergenic substances, thereby increasing the risk of asthma in accordance with the hygiene hypothesis. Results of previous studies regarding an association between birth route and asthma are conflicting, and these studies have not evaluated some potential confounding effects, including prematurity and maternal asthma. OBJECTIVE: To determine whether cesarean delivery in full-term and premature infants increases the risk of subsequent childhood asthma hospitalization. METHODS: We conducted a case-control study using the Washington State Birth Events Record Database linked to statewide hospitalization data. The study included 2,028 children hospitalized for asthma (cases) and 8,292 age-matched controls. RESULTS: Cesarean delivery was modestly associated with an increased risk of asthma hospitalization (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.04-1.39). However, when analyzed separately, there was an association between cesarean delivery and asthma hospitalization in premature infants (OR, 1.90; 95% CI, 1.09-3.02) but not in full-term infants (OR, 1.15; 95% CI, 0.97-1.34). CONCLUSIONS: Cesarean delivery was associated with subsequent asthma hospitalization only in premature infants. Because mothers with asthma are reported to have increased rates of cesarean delivery and premature delivery, other factors in addition to the hygiene hypothesis, including genetic and in utero influences associated with maternal asthma, may contribute to the increased risk of asthma in premature infants.     

Venous thromboembolism in patients with HIV/AIDS: a case-control study

BACKGROUND: Retrospective cohort studies of HIV-infected patients suggest an incidence of venous thromboembolism (VTE) of 1% to 2%, which is 10 times that expected among people without HIV. We investigated the prevalence of established risk factors for VTE in this population and explored novel risk factors. METHODS: We conducted a case-control study using patients in the Johns Hopkins University AIDS Service cohort. We used conditional logistic regression and paired t tests to test for covariates significantly associated with VTE. RESULTS: We identified 160 patients with VTE diagnosed radiologically or with a clinical course consistent with VTE; 23% of the cases of VTE were diagnosed in hospitalized patients. The incidence of VTE was approximately 0.5% per patient-year. Patients with VTE and control patients did not differ by gender, but black patients were overrepresented among those with VTE (odds ratio [OR]=1.9, 95% confidence interval [CI]: 1.11 to 3.08) and patients with VTE were older than controls (mean: 39 vs. 37 years; P=0.001). Patients with VTE had lower CD4 counts (229 vs. 362 cells/mm; P<0.0001), higher HIV RNA titers (120,254 vs. 71,262 copies/mL; P=0.013), and lower hemoglobin concentrations (11.4 vs. 12.7 g/dL; P<0.0001) preceding the event than those without VTE. The use of highly active antiretroviral therapy was not associated with VTE. In multivariate analyses, independent risks for VTE were age, hospitalization in the past 3 months (OR=13, 95% CI: 6.4 to 27), central venous catheter use in the past 3 months (OR=6.0, 95% CI: 2.3 to 16), and a CD4 count<500 cells/mm (OR=3.0, 95% CI: 1.2 to 7.8). CONCLUSIONS: The incidence of VTE in our cohort is similar to that reported in other cohorts of patients with HIV. Recent hospitalization was the risk factor most strongly associated with VTE.     

Predictors of indoor exposure to mouse allergen in urban and suburban homes in Boston

BACKGROUND: Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases. AIMS OF THE STUDY: To assess indoor mouse allergen exposure in early life among children with parental history of asthma or allergies. METHODS: Prospective birth cohort study of 498 children with a history of allergy or asthma in at least one parent living in metropolitan Boston. RESULTS: Of the 498 participating children, 357 (71.7%) resided outside the city of Boston and 439 (90.7%) lived in households with incomes > 30,000 dollars. Mouse allergen was detected in 42% of the homes of study participants. In a multivariate analysis adjusting for sex, income, and endotoxin, black race [odds ratio (OR) = 3.0; 95% confidence interval (CI) = 1.3-6.6, P = 0.009], signs of mice in the home at age 2-3 months (OR = 3.0; 95% CI = 1.6-5.6, P = 0.0006), and kitchen cockroach allergen levels > or = 0.05 to < 2 U/g (OR = 1.8; 95% CI = 1.1-3.2, P = 0.02) were associated with detectable mouse allergen in the kitchen. In this model, living in a single detached house was inversely associated with detectable kitchen mouse allergen levels (OR = 0.4; 95% CI = 0.2-0.6, P = 0.0001). CONCLUSION: Infants with a parental history of asthma or allergies are commonly exposed to mouse allergen in their homes. Among infants at high risk for atopy, predictors of increased mouse allergen levels included black race, reported mice exposure, and moderate levels of cockroach allergen.     

Efficacy of a consensus protocol therapy in adults with acute, severe asthma.

BACKGROUND: International guidelines recommend multiple doses of inhaled beta2-agonists and anticholinergics plus early administration of systemic corticosteroids for acute, severe asthma. This study examined the efficacy of this protocol in adults and analyzed those factors associated with unresponsiveness to the protocol therapy. OBJECTIVE: Ninety-three consecutive patients 18 to 55 years old presenting for treatment of acute asthma with a peak expiratory flow rate (PEFR) < or = 50% of the predicted value were analyzed. METHODS: All subjects received 400 microg of salbutamol every 20 minutes for three doses and 400 microg of oxitropium bromide with each of the three salbutamol doses by means of a metered-dose inhaler with a spacer device, plus intravenously 8 mg betamethasone. PEFR was measured at baseline and at 20, 40, 60, and 120 minutes. RESULTS: Sixty-nine percent of subjects improved sufficiently to be discharged. In 31% of subjects, the protocol therapy failed. There were no significant differences in age, sex, smoking status, or beta-agonist use within 6 hours between the two groups. Logistic regression analysis demonstrated that a PEFR < 35% of the predicted value at presentation (odds ratio [OR]; 16.3, 95% confidence interval [CI] 4.5 to 59.9), viral respiratory tract infection symptoms > or = 2 days (OR, 4.8, 95% CI 1.3 to 17.1), and asthma hospitalization in the past year (OR, 4.6, 95% CI 1.1 to 19.9) were significantly associated with unresponsiveness to the protocol. CONCLUSIONS: Unresponsiveness to protocol therapy occurs in nearly one-third of individuals presenting with acute, severe asthma. Our findings underscore the need to explore more effective strategies for improving lung function and reducing hospital admission rates.     

Meta-analysis of the association of beta2-adrenergic receptor polymorphisms with asthma phenotypes

BACKGROUND: Two common polymorphisms of the beta2-adrenergic receptor gene (Arg16Gly and Gln27Glu ) have been extensively studied for their possible association with asthma-related phenotypes, but the results of individual studies have been inconclusive. OBJECTIVE: We aimed to integrate quantitatively the available evidence on the association of the Arg16Gly and the Gln27Glu polymorphisms with asthma, nocturnal asthma, asthma severity, and bronchial hyperresponsiveness. METHODS: Meta-analysis of case-control and cohort studies using random effects models. RESULTS: A total of 28 studies were included in the meta-analysis. The summary estimates suggested that neither the Gly16 nor the Glu27 allele contributes to asthma susceptibility overall (odds ratio [OR], 1.01; 95% CI, 0.90-1.13; and OR, 0.95; 95% CI, 0.83-1.09, respectively) or to bronchial hyperresponsiveness (OR, 0.90; 95% CI, 0.77-1.05; and OR, 1.07; 95% CI, 0.94-1.22, respectively). There was a strong association of Gly16 with nocturnal asthma (OR, 2.20; 95% CI, 1.56-3.11) and a less strong association with severe or moderate rather than milder asthma (OR, 1.42; 95% CI, 1.04-1.94). No such effects were seen for the Glu27 allele (OR, 1.02; 95% CI, 0.74-1.40; and OR, 0.82; 95% CI, 0.59-1.14, respectively). Moreover, there was evidence that Gly16 homozygotes had a much higher risk for nocturnal asthma (OR, 5.15; 95% CI, 2.44-10.84) and asthma severity (OR, 2.84; 95% CI, 1.62-4.96) than the Arg16 homozygotes. CONCLUSION: The Gly16 allele of the beta2-adrenergic receptor gene predisposes to nocturnal asthma, and this may also explain the association with asthma severity. Neither polymorphism modulates the risk for bronchial hyperresponsiveness or mild asthma.     

Does the use of antibiotics in early childhood increase the risk of asthma and allergic disease?

BACKGROUND: One of the mechanisms evoked to explain the increasing prevalences of asthma and allergy, in particular among children, is the 'Western lifestyle' or 'hygiene' hypothesis. As early childhood infections are assumed to hold a protective effect on the development of asthma and allergies, the use of antibiotics at that sensitive age may lead to an increased risk of asthma and allergy. OBJECTIVE: The aim of this study is to investigate the association between the use of antibiotics in the first year of life and the subsequent development of asthma and allergic disorders. METHODS: In a population-based sample of 7-and-8-year-old children questionnaire and skin prick test data were collected from 1206 and 675 subjects, respectively. Prevalence rates of asthma, allergic disorders and skin test positivity were compared between children with and without early life use of antibiotics, taking into account other possible risk factors including early respiratory infections. The effect of genetic predisposition was investigated by stratified analyses of children with and without parental hay fever. RESULTS: The use of antibiotics during the first year of life was significantly associated with asthma (OR = 1.7, 95% CI 1.0-3.1), hay fever (OR = 2.3, 95% CI 1.3-3.8) and eczema (OR = 1.3, 95% CI 1.0-1.8). No significant relationship was found with skin test positivity (OR = 1.1, 95% CI 0.7-1.7). After stratification for the presence of parental hay fever, children without parental hay fever did not show any significant associations between antibiotics use and asthma or allergy, whereas in children with parental hay fever the use of antibiotics was significantly related with asthma (OR = 2.3, 95% CI 1.1-5.1), hay fever (OR = 2.8, 95% CI 1.5-5.1) and eczema (OR = 1.6, 95% CI 1.0-2.6), and of borderline statistical significance with skin test positivity (OR = 1.6, 95% CI 0.9-3.0). CONCLUSION: Early childhood use of antibiotics is associated with an increased risk of developing asthma and allergic disorders in children who are predisposed to atopic immune responses. These findings support recent immunological understanding of the maturation of the immune system.     

Insurance status and asthma-related health care utilization in patients with severe asthma.

BACKGROUND: Medicaid insurance has been associated with worse asthma outcomes, but the degree to which demographic factors contribute to this relationship has not been well explored. OBJECTIVE: To evaluate whether insurance status is independently associated with health care utilization (HCU) and asthma control when demographic differences are taken into account. METHODS: We used baseline data from adults with severe asthma in the Epidemiology and Natural History of Asthma: Outcomes and Treatment Regimens study. HCU was defined as hospitalization or emergency department visit for asthma in the past 3 months. Asthma control was evaluated using the Asthma Therapy Assessment Questionnaire. Multiple logistic regression was used to compare HCU and asthma control in patients with Medicaid vs those with private health insurance. RESULTS: Of 1315 patients analyzed, 130 (9.9%) had Medicaid insurance and 1,185 (90.1%) had private insurance. Medicaid insurance was associated with younger age, female sex, race other than white, obesity, active smoking, lower education level, and unemployment. In unadjusted analyses, Medicaid patients had significantly higher HCU (odds ratio [OR], 3.08; 95% confidence interval [CI], 2.11-4.50) and poorer asthma control (OR, 2.56; 95% CI, 1.84-3.57) compared with patients with private insurance. After adjusting for demographic differences, insurance status was no longer associated with HCU (OR, 1.43; 95% CI, 0.92-2.23), and the strength of its association with asthma control was reduced (OR, 1.67; 95% CI, 1.17-2.40). CONCLUSIONS: Medicaid insurance is not associated with increased HCU in patients with severe asthma once demographic factors have been taken into account but remains modestly associated with poorer asthma control.     

Antibiotic use in early childhood and the development of asthma

BACKGROUND AND OBJECTIVE: Recent investigations have focused on the role of infections in infancy in promoting or protecting against the subsequent development of asthma. A related hypothesis concerns the possible role of medical responses to infections, including the widespread use of antibiotics. We chose children at Rudolf Steiner schools to test this latter hypothesis because a significant proportion of parents rejects the use of conventional treatments, including antibiotics. METHODS: Seventy-five per cent (n = 456) of parents of children aged 5-10 years attending Rudolf Steiner schools throughout New Zealand completed questionnaires which included questions on the use of antibiotics and a history of asthma and wheeze in their children. RESULTS: After controlling for potential confounders, antibiotic use was significantly associated with having a history of asthma (OR = 2.74, 95% CI: 1.10-6.85) or wheeze (OR = 1. 86, 95% CI: 1.06-3.26) but not with current wheeze (OR = 1.08, 95% CI: 0.54-2-16). The adjusted odds ratio for asthma was 4.05 (95% CI: 1.55-10.59) if antibiotics were used in the first year of life and 1. 64 (95% CI: 0.60-4.46) if antibiotics had been used only after the first year of life when compared with children who had never used antibiotics. The number of courses of antibiotics during the first year of life was also associated with increased odds ratios for asthma: 2.27 (95% CI: 1.14-4.51) for one to two courses and 4.02 (95% CI: 1.57-10.31) for three or more courses when compared with no antibiotic use in the first year of life. Although not significant, the association of antibiotics and hay fever (OR = 1.99 [95% CI: 0. 93-4.26]) was of a similar strength to the association of antibiotics with a history of wheeze. Antibiotics were not significantly associated with eczema (OR = 1.23 [95% CI: 0.71-2.13]). CONCLUSION: Antibiotic use in infancy may be associated with an increased risk of developing asthma. Further study is required to determine the reasons for this association.     

Risk factors for death from asthma. Prairie Provinces Asthma Study Group.

BACKGROUND: Asthma mortality rates have increased in Canada and worldwide. Within Canada, the highest rates were seen in the prairie provinces. OBJECTIVE: The objective was to determine risk factors for fatal asthma by comparing those who died of an acute exacerbation with those who attended an emergency department for treatment of asthma. METHODS: The case-control study included all deaths from asthma among those aged 5 to 50 years in Alberta, Saskatchewan and Manitoba from November, 1992 through October, 1995 (cases). The 35 fatalities were matched to 209 controls by age, gender, time of the index event and residence. RESULTS: Cases were more likely than controls to have had severe asthma, an unscheduled physician visit in the past year, a past hospitalization for asthma, and to have been intubated. Both groups reported frequent, regular asthma symptoms. Beta-agonist bronchodilator use was more common among cases, as was use in excess of prescribed amounts. Use of inhaled steroids did not differ between groups. Prior to the index event controls were more likely to report a cold or flu (OR = 0.27; 95% CI: 0.10 to 0.72) and that medications were "not working" (OR = 0.30; 95% CI: 0.12 to 0.71). Cases were more often sad and depressed (OR = 2.88; 95% CI: 1.03 to 8.05). Time between onset/recognition of symptoms and the event was significantly shorter for cases than controls. CONCLUSIONS: Both groups tolerated high levels of regular symptoms, suggesting poor management. Opportunities for intervention existed for both groups near the time of the event. The short time between recognition of symptoms and death suggests patients at increased risk should monitor their condition closely and take action in response to predetermined criteria.     

Household mouse allergen exposure and asthma morbidity in inner-city preschool children.

BACKGROUND: Inner-city children experience disproportionate asthma morbidity, and suspected reasons include indoor environmental exposures. OBJECTIVE: To determine if mouse allergen exposure is a risk factor for asthma morbidity. METHODS: Preschool children with asthma were recruited from inner-city Baltimore, MD. Skin testing was performed and blood was collected at the baseline visit for quantification of mouse allergen specific IgE. A questionnaire evaluated symptoms, medication, and health care use at baseline, 3 months, and 6 months. A trained technician collected dust samples from the child's home for analysis of Mus m 1 at baseline, 3 months, and 6 months. Outcomes were compared between mouse-sensitized, highly exposed children and all other children. RESULTS: A total of 127 children had complete data for mouse sensitization status and bedroom settled dust mouse allergen levels at baseline. The mean age of the children was 4.4 years, 92% were African American, and 26% were sensitized to mouse. Mouse-sensitized children exposed to higher levels of Mus m 1 (>0.5 microg/g) had 50% more days of symptoms (incidence rate ratio [IRR], 1.5; 95% confidence interval [CI], 1.1-2.1) and 80% more days of beta-agonist use than other children (IRR, 1.8; 95% CI, 1.3-2.5). Children in the sensitized and highly exposed group were also more likely to have an unscheduled physician visit (odds ratio [OR], 3.1; 95% CI, 1.6-6.3), emergency department visit (OR, 2.1; 95% CI, 1.1-4.1), and hospitalization (OR, 36.6; 95% CI, 4.1-327.3) than other children. These associations between mouse allergen exposure and asthma symptoms and morbidity remained statistically significant after adjusting for potential confounders, including atopy and cockroach sensitization and exposure. CONCLUSIONS: In mouse-sensitized inner-city children, exposure to mouse allergen may be an important cause of asthma morbidity.     

Do asthma and allergy influence subsequent pet keeping? An analysis of childhood and adulthood

BACKGROUND: Asthma and allergy might influence the choice of keeping pets, leading to apparent protective effects of pets on allergic disease. OBJECTIVE: We investigated the effects of asthma and allergy on subsequent pet keeping in childhood and adulthood. METHODS: Information about asthma and pet keeping at ages 0 to 4, 5 to 15, 20 to 44, and 26 to 56 years was provided by 9812 subjects participating in the 9-year follow-up of the European Community Respiratory Health Survey. RESULTS: In childhood asthma debut at younger than 5 years was associated with less cat keeping at 5 to 15 years (odds ratio [OR], 0.60; 95% CI, 0.44-0.82), an effect only observed when the parents did not have asthma or allergy (P(interaction) = .045). Childhood asthma did not influence adult pet ownership, unless there were adult symptoms. Adults less often acquired cats at follow-up if they had 3 or more asthma symptoms (OR, 0.78; 95% CI, 0.64-0.95), were taking asthma medication (OR, 0.48; 95% CI, 0.31-0.74), had hay fever (OR, 0.75; 95% CI, 0.62-0.91), had atopy (OR, 0.75; 95% CI, 0.61-0.91), or had specific IgE to cat (OR, 0.57; 95% CI, 0.39-0.82) at baseline. Adults who already had pets usually continued keeping the same type of pet, except that the presence of 3 or more asthma symptoms was associated with less subsequent dog keeping (OR, 0.69; 95% CI, 0.53-0.89). Pet removal between surveys to reduce allergen was reported by 4.7%. CONCLUSION: Selective avoidance subsequent to asthma or allergy was observed for childhood cat keeping and adult cat acquisition. Avoidance would produce an apparent protective effect of cats on childhood asthma (large OR, 0.83). Avoidance was generally not observed for dogs or birds. CLINICAL IMPLICATIONS: A part of the protective effects of childhood cats on asthma and allergy can be attributed to selective avoidance.     

Food allergy is associated with an increased risk of asthma

Background The atopic march is well documented, but the interrelationship of food allergy (FA) and asthma is not well understood.
Objective The aim of this study was to examine the strength of the association and temporal relationships between FA and asthma.
Methods This analysis included 271 children 6 years (older group) and 296 children <6 years (younger group) from a family-based FA cohort in Chicago, IL. Asthma was determined by parental report of physician diagnosis. FA status was determined based on the type and timing of clinical symptoms after ingestion of a specific food, and results of prick skin test (Multi-Test II) and allergen-specific IgE (Phadia ImmunoCAP). Analyses were carried out using logistic regression accounting for important covariates and auto-correlations among siblings. Kaplan–Meier curves were used to compare the time to onset of asthma with the FA status.
Results Symptomatic FA was associated with asthma in both older [odds ratio (OR)=4.9, 95% confidence interval (CI): 2.5–9.5] and younger children (OR=5.3, 95% CI: 1.7–16.2). The association was stronger among children with multiple or severe food allergies, especially in older children. Children with FA developed asthma earlier and at higher prevalence than children without FA (Cox proportional hazard ratio=3.7, 95% CI: 2.2–6.3 for children 6 years, and hazard ratio=3.3, 95% CI: 1.1–10 for children <6 years of age). No associations were seen between asymptomatic food sensitization and asthma.
Conclusions Independent of markers of atopy such as aeroallergen sensitization and family history of asthma, there was a significant association between FA and asthma. This association was even stronger in subjects with multiple food allergies or severe FA.     

Impact of depressive symptoms on adult asthma outcomes.

BACKGROUND: Psychological disorders, including depression, are common in adults with asthma. Although depression is treatable, its impact on longitudinal asthma outcomes is not clear. OBJECTIVE: To elucidate the impact of depressive symptoms on patient-centered outcomes and emergency health care use in adults with asthma. METHODS: We conducted a prospective cohort study of 743 adults with asthma who were recruited after hospitalization for asthma. Depressive symptoms were defined as having a score of 16 or more on the Center for Epidemiologic Studies Depression Scale. We examined the impact of depressive symptoms on patient-centered outcomes (validated severity-of-asthma score, Marks Asthma Quality of Life Questionnaire, and 12-Item Short-Form Health Survey physical component summary score) and on future emergency health care use for asthma ascertained from computerized databases. RESULTS: The prevalence of depressive symptoms was 18% (95% confidence interval [CI], 15%-21%) among adults with asthma. Depressive symptoms were associated with greater severity-of-asthma scores after controlling for age, sex, race/ ethnicity, educational attainment, and cigarette smoking (mean score increment, 2.6 points; 95% CI, 1.8-3.4 points). Furthermore, depressive symptoms were associated with poorer asthma-specific quality of life (mean score increment, 19.9 points; 95% CI, 17.7-22.1 points) and poorer physical health status (mean score decrement, 3.7 points; 95% CI, 1.5-5.8 points). Depressive symptoms were associated with a greater longitudinal risk of hospitalization for asthma (hazard ratio, 1.34; 95% CI, 0.98-1.84). After controlling for differences in preventive care for asthma, the relationship was stronger (hazard ratio, 1.45; 95% CI, 1.05-2.0). CONCLUSION: Depressive symptoms are common in adults with asthma and are associated with poorer health outcomes, including greater asthma severity and risk of hospitalization for asthma.