Subsequent Diagnosis Of Asthma Research Articles

The role of school safety perceptions in childhood asthma diagnosis disparities.

Childhood racial and ethnic asthma disparities in the United States are the consequence of structural inequities such as those in socioeconomic status (SES) and exposure to violence, but little research has explored the role of the school environment in perpetuating racial and ethnic disparities. This study examines associations between perceptions of unsafe school environments (USEs) and subsequent asthma diagnosis for elementary-aged children and the extent to which USE mediates relations from SES and race/ethnicity to asthma diagnosis for Black, Latinx, and non-Latinx White children. We conducted a secondary analysis of data from the Early Childhood Longitudinal Study. Structural equation modeling was used to evaluate the association between USE and subsequent asthma diagnosis, controlling for child sex, and indirect effects of SES and race/ethnicity on asthma diagnosis via USE. For 6,532 children, USE in second grade positively predicted new asthma diagnoses in third grade and mediated the association between SES and new asthma diagnosis. SES and USE serially mediated the relationship between race/ethnicity and asthma diagnosis. Identifying as non-Latinx White was associated with a lower likelihood of subsequent asthma diagnosis via higher SES and lower USE while identifying as Black or Latinx was associated with a higher likelihood of subsequent asthma diagnosis via lower SES and higher USE. USE was associated with pediatric asthma diagnosis and mediated the relationship between SES and asthma diagnosis as well as race/ethnicity and asthma diagnosis. Findings highlight the need to consider USE as a social determinant of health for pediatric asthma. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Association between tobacco product use and respiratory health and asthma-related interference with activities among U.S. Adolescents

Tobacco use adversely affects long-term respiratory health. We examined the relationship between sole and dual tobacco product use and both respiratory health and respiratory-related quality of life during adolescence in the U.S.Using adolescent data (baseline age 12–17) from Waves 4.5 (data collected from December 2017-December 2018) and 5 (data collected from December 2018-November 2019) of the Population Assessment of Tobacco and Health Study, we examined the associations between combustible (i.e., cigarette or cigar), vaped, and dual (i.e., both cigar/cigarette and e-cigarette) tobacco/nicotine use at baseline and two respiratory symptoms (all adolescents, n = 11,748) and new asthma diagnosis (adolescents with no baseline diagnosis, n = 9,422) at follow-up. Among adolescents with asthma (Wave 5, n = 2,421), we estimated the association between current tobacco use and the extent to which asthma interfered with daily activities.At follow-up, 12.3 % of adolescents reported past 12-month wheezing/whistling, 17.4 % reported past 12-month dry cough, and 1.9 % reported newly diagnosed asthma. Baseline current cigarette/cigar smoking was associated with subsequent wheezing/whistling and baseline report of another tobacco product use pattern was associated with subsequent asthma diagnosis. Among adolescents with asthma, 5.7 % reported it interfering with activities some of the time and 3.1 % reported interference most/all of the time in the past 30 days. Past 30-day sole cigarette/cigar smoking and dual use was positively associated with asthma-related interference with activities compared to never tobacco use and sole e-cigarette use.Combustible and dual tobacco use pose direct risk to respiratory health and indirect risk to quality of life through respiratory health.

Association of Early Childhood Wheeze and Asthma Diagnosis Documentation by Race, Ethnicity, and Language in Children.

To determine whether electronic health record (EHR) documentation of certain early childhood risk factors for asthma, such as wheeze differ by race, ethnicity, and language group, and whether these children have different subsequent asthma prevalences. We used EHR data from the Accelerating Data Value Across a National Community Health Center (ADVANCE) Clinical Research Network from children receiving care in US community health centers (n = 71,259 children) across 21 states to examine the presence of ICD-coded documentation of early childhood wheeze and its association with subsequent asthma diagnosis documentation in the EHR by race/ethnicity/language. ICD-coded wheeze was present in 2 to 3% of each race/ethnicity/language group. Among the total sample, 18.5% had asthma diagnosed after age 4. The adjusted prevalence of subsequent asthma diagnosis was greater in children with wheeze than those without. Odds of asthma diagnosis did not differ among children in all race/ethnicity/language groups with early childhood wheeze. Non-Latino Black children without wheeze had higher odds of asthma (OR = 1.19, 95% CI = 1.08-1.32) compared with non-Latino White children without wheeze. In US community health centers which serve medically underserved populations, EHR documentation of early childhood wheeze was uncommon and did not differ significantly among race/ethnicity/language groups. Differences in asthma diagnosis in Latinos may not stem from differences in early-life wheeze documentation. However, our findings suggest that there may be opportunities for improvement in early asthma symptom recognition for non-Latino Black children, especially in those without early childhood wheeze.

Associations Between Asthma Diagnosis/Asthma Exacerbation and Previous Proton-Pump Inhibitor use: A Nested Case-Control Study Using a National Health Screening Cohort.

Background: Proton-pump inhibitors (PPIs) block acid secretion from gastric parietal cells; however, recent studies have reported that PPIs have antioxidant and anti-inflammatory properties in various cells. Newer PPIs are stronger inhibitors of acid secretion; however, the anti-inflammatory effects of these drugs have not been assessed. We evaluated anti-inflammatory effect of PPIs on the development of asthma/asthma exacerbation (AE) in a national health screening cohort. Methods: This case-control study comprised 64,809 participants with asthma who were 1:1 matched with controls from the Korean National Health Insurance Service-Health Screening Cohort. Conditional logistic regression analysis was used to evaluate the effect of previous PPI use on an asthma diagnosis in all participants. Unconditional logistic regression was used to assess the effect of PPI use on AE in participants with asthma. These relationships were estimated in a subgroup analysis according to PPI generation. Results: Overall, PPI use increased the risk of asthma diagnosis [adjusted odds ratio (aOR) = 1.29, 95% confidence interval (CI) = 1.23–1.35, p < 0.001]. Use of the first-generation PPIs was associated with asthma (aOR = 1.34, 95% CI = 1.18–1.52, p < 0.001), while use of second-generation PPIs was not (aOR = 0.97, 95% CI = 0.82–1.15, p = 0.748). In contrast, overall PPI use decreased the risk of AE in participants with asthma (aOR = 0.79, 95% CI = 0.75–0.84, p < 0.001), although this effect was observed only for second-generation PPIs (aOR = 0.76, 95% CI = 0.65–0.89, p = 0.001). Conclusion: PPI use increased the risk for subsequent asthma diagnosis. However, this effect was confined to first-generation PPIs. Second-generation PPIs decreased the risk of AE.

The Role of Interferons in Driving Susceptibility to Asthma Following Bronchiolitis: Controversies and Research Gaps.

Bronchiolitis is the most common cause of hospitalization in infancy and is associated with a higher risk for the development of childhood asthma. However, not all children hospitalized with bronchiolitis will develop asthma. The mechanisms underlying asthma development following bronchiolitis hospitalization are complex. Immune responses to respiratory viruses may underlie both bronchiolitis severity and long-term sequela (such as asthma). Interferons (IFNs) are important components of innate immune responses to respiratory viruses and could influence both asthma development and asthma exacerbations. However, the nature of the relationship between interferon production and wheezing illnesses is controversial. For example, low peripheral blood IFN responses at birth have been linked with recurrent wheeze and asthma development. In contrast, there is evidence that severe illnesses (e.g., hospitalization for bronchiolitis) are associated with increased IFN responses during acute infection (bronchiolitis hospitalization) and a higher risk for subsequent asthma diagnosis. Furthermore, mechanistic studies suggest that bronchial epithelial cells from asthmatic children have impaired IFN responses to respiratory viruses, which may enable increased viral replication followed by exaggerated secondary IFN responses. This review aims to discuss controversies around the role of IFNs as drivers of susceptibility to asthma development following bronchiolitis hospitalization. Past evidence from both mechanistic and cohort studies are discussed. We will highlight knowledge gaps that can inform future research study design.

Clinical Outcomes for Young Children Diagnosed With Asthma Versus Reactive Airway Disease

ObjectiveClinical diagnoses of asthma and reactive airway disease (RAD) in young children are subjective. We examined how often children were diagnosed with asthma versus RAD, and whether preventive care and 2-year clinical outcomes differed based on initial diagnosis. MethodsWe conducted a retrospective cohort analysis of children (2–7 years) from a university-based general pediatrics practice who had been diagnosed with RAD or asthma. We performed adjusted comparisons between groups for time until subsequent asthma-related care. We also compared delivery of asthma-related healthcare services, corticosteroid and controller prescriptions, and action plans within 2 years of index diagnosis, using bivariate and regression analyses. ResultsFour hundred three children were included (64% male, 67% Black, 25% Hispanic). RAD was diagnosed in 62% of index visits, and was more likely than asthma to be diagnosed in emergency settings. In the full sample, the time between index visit and subsequent asthma care did not differ between groups, after adjustment for index location. For subjects with complete 24-month follow-up (N = 300), no between-group differences were found in adjusted analyses. Most children with RAD received action plans and controller medications only after a subsequent asthma diagnosis, on average, 9 months after their index visit. ConclusionsRAD diagnoses were linked to delayed delivery of preventive care measures, but within 2 years of initial diagnosis, clinical outcomes for those diagnosed with RAD and asthma did not differ. To facilitate clear communication and timely treatment, a prompt diagnosis of asthma, rather than RAD, should be considered for children with asthma symptoms.

Intrapartum Group B Streptococcal Prophylaxis and Childhood Allergic Disorders.

To determine if maternal intrapartum group B Streptococcus (GBS) antibiotic prophylaxis is associated with increased risk of childhood asthma, eczema, food allergy, or allergic rhinitis. Retrospective cohort study of 14 046 children. GBS prophylaxis was defined as administration of intravenous penicillin, ampicillin, cefazolin, clindamycin, or vancomycin to the mother, ≥4 hours before delivery. Composite primary outcome was asthma, eczema, or food allergy diagnosis within 5 years of age, identified by diagnosis codes and appropriate medication prescription. Allergic rhinitis was defined by using diagnostic codes only and analyzed as a separate outcome. Analysis was a priori stratified by delivery mode and conducted by using Cox proportional hazards model adjusted for multiple confounders and covariates. Secondary analyses, restricted to children retained in cohort at 5 years' age, were conducted by using multivariate logistic regression. GBS prophylaxis was not associated with increased incidence of composite outcome among infants delivered vaginally (hazard ratio: 1.13, 95% confidence interval [CI]: 0.95-1.33) or by cesarean delivery (hazard ratio: 1.08, 95% CI: 0.88-1.32). At 5 years of age, among 10 404 children retained in the study, GBS prophylaxis was not associated with the composite outcome in vaginal (odds ratio: 1.21, 95% CI: 0.96-1.52) or cesarean delivery (odds ratio: 1.17, 95% CI: 0.88-1.56) cohorts. Outcomes of asthma, eczema, food allergy, separately, and allergic rhinitis were also not associated with GBS prophylaxis. Intrapartum GBS prophylaxis was not associated with subsequent diagnosis of asthma, eczema, food allergy, or allergic rhinitis in the first 5 years of age.

Live Attenuated Influenza Vaccination Before 3 Years of Age and Subsequent Development of Asthma: A 14-year Follow-up Study.

Background:Live-attenuated influenza vaccines (LAIVs) are not licensed in children younger than 2 years of age because of a wheezing safety signal that has not been fully elucidated. In 2000, the Kaiser Permanente Vaccine Study Center conducted a placebo-controlled randomized clinical trial (RCT) of LAIV in children. As many of these children were still enrolled in Kaiser Permanente in 2014, we could assess the possible long-term association between LAIV and subsequent asthma diagnosis.Methods:We identified all children who were originally enrolled into the LAIV RCT at younger than 3 years of age. We followed up subjects until disenrollment from the health plan, a first diagnosis of asthma, or through the end of the study period in 2014. Asthma was defined by a first International Classification of Diseases, 9th revision, Clinical Modification code (493.*) assigned at an outpatient or emergency department encounter. We performed a survival analysis of time to first asthma diagnosis among children receiving LAIV or placebo with a Cox proportional hazards model.Results:We identified 1151 children in the original RCT who were 12 through 35 months of age at the time of enrollment and who had received 2 doses of LAIV or placebo. A total of 767 (66.7%) RCT participants were still Kaiser Permanente Northern California members in 2014. There was no evidence of differential dropout by treatment group. The hazard ratio for new-onset asthma for LAIV recipients compared with placebo was 1.1 (95% confidence interval: 0.88–1.41; P = 0.38).Conclusions:We found no evidence of increased risk of subsequent asthma diagnosis among children younger than 3 years of age who received LAIV compared with placebo.

A population-based study investigating chronic rhinosinusitis and the incidence of asthma.

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses, associated with reduced health-related quality of life and increased utilization of healthcare services. Chronic upper and lower respiratory diseases often coexist, although the extent to which CRS is associated with developing asthma remains unclear. To investigate the effect of CRS on receiving a subsequent diagnosis of asthma, we used data from a previously conducted national, longitudinal survey. Respondents from the Canadian National Population Health Survey from 1998/1999 to 2010/2011 were used. Data were analyzed from 11,555 (66.9%) subjects, ≥ 19 years of age and reporting no asthma at baseline. Respondents were reviewed for 12 years to determine the cumulative incidence of asthma. Logistic regression was used to estimate the effect of CRS on the development of asthma, adjusting for age, gender, body mass index, cigarette smoking, and food- or nonfood-related allergies. During the 12-year study period, 6.0% (95% confidence interval [CI] [95% CI]: 5.4%-6.7%) of respondents developed asthma. Baseline CRS (odds ratio [OR]: 2.7, 95% CI: 1.9-3.9), female gender (OR: 1.4, 95% CI: 1.1-1.8), and allergies (OR: 2.6, 95% CI: 2.1 - 3.3) were significantly associated with developing asthma. After adjustment, respondents with CRS were significantly more likely to develop asthma than non-CRS counterparts (OR: 2.0, 95% CI: 1.4-2.9). Results indicate that one in 13 individuals with CRS will be subsequently diagnosed with asthma. Given the economic burden and use of healthcare services associated with asthma, providers managing CRS may consider increased awareness and subsequent treatment for asthma. 4. Laryngoscope, 126:1296-1302, 2016.

The relationship of early-life antibiotic use with asthma in at-risk children

As the prevalence of asthma has doubled in developed countries over the last 30 years, the concurrent increase in children's antibiotic use has led to speculation of a possible causal relationship.1 Retrospective studies focused on the hygiene hypothesis have shown correlations with early antibiotic use.2 These findings, however, may be due to reverse causation, or confounding by indication. Existing evidence is inconsistent, and there have been few prospective studies. Controlling for temporal confounders within a prospective study, we investigated the effects of antibiotic use in the first year of life with subsequent asthma diagnosis and wheezing in the third year of life within a high-risk urban cohort.

Early-Life Air Pollution and Asthma Risk in Minority Children. The GALA II and SAGE II Studies

Air pollution is a known asthma trigger and has been associated with short-term asthma symptoms, airway inflammation, decreased lung function, and reduced response to asthma rescue medications. To assess a causal relationship between air pollution and childhood asthma using data that address temporality by estimating air pollution exposures before the development of asthma and to establish the generalizability of the association by studying diverse racial/ethnic populations in different geographic regions. This study included Latino (n = 3,343) and African American (n = 977) participants with and without asthma from five urban regions in the mainland United States and Puerto Rico. Residential history and data from local ambient air monitoring stations were used to estimate average annual exposure to five air pollutants: ozone, nitrogen dioxide (NO₂), sulfur dioxide, particulate matter not greater than 10 μm in diameter, and particulate matter not greater than 2.5 μm in diameter. Within each region, we performed logistic regression to determine the relationship between early-life exposure to air pollutants and subsequent asthma diagnosis. A random-effects model was used to combine the region-specific effects and generate summary odds ratios for each pollutant. After adjustment for confounders, a 5-ppb increase in average NO₂ during the first year of life was associated with an odds ratio of 1.17 for physician-diagnosed asthma (95% confidence interval, 1.04-1.31). Early-life NO₂ exposure is associated with childhood asthma in Latinos and African Americans. These results add to a growing body of evidence that traffic-related pollutants may be causally related to childhood asthma.

Corticosteroids for acute and subacute cough following respiratory tract infection: a systematic review

Cough associated with acute respiratory tract infection (RTI) is one of the most common problems managed in primary care. Despite minimal evidence for the use of antibiotics, they continue to be prescribed at great cost and are a significant cause of emerging bacterial resistance. To carry out a systematic review of randomized controlled trials to evaluate the effect of corticosteroid therapy in otherwise-healthy adults with acute RTI. Seven electronic databases and five ongoing trial registers were searched. Studies were eligible if they compared the use of any corticosteroid treatment against a control group in adults with an acute (<3 weeks) or subacute (<8 weeks) cough associated with an RTI but no asthma. Primary outcomes were differences in mean cough and other symptom scores. Secondary outcomes included adverse effects, subsequent diagnosis of asthma and patient satisfaction. Four trials (335 participants) investigating the effects of inhaled corticosteroids were identified. None investigated the use of oral corticosteroids. Results were mixed, with two reporting equivalence and two reporting benefits for mean cough score (P = 0.012) and cough frequency (P = 0.047). One reported additional benefits in non-smokers. Adverse events were rare and there were no data on patient satisfaction or the subsequent diagnosis of asthma. Most trials were of unclear risk of bias. Study outcomes were too heterogeneous to meta-analyse. There is insufficient evidence to recommend the routine use of inhaled corticosteroids for acute RTI in adults. However, some trials have shown benefits, suggesting the need for further high-quality, adequately powered trials.

Determinants of asthma after severe respiratory syncytial virus bronchiolitis

The development of asthma after respiratory syncytial virus (RSV) bronchiolitis has been demonstrated in case-control studies, although the determinants of post-RSV asthma remain undefined. We sought to evaluate the potential determinants of physician-diagnosed asthma after severe RSV bronchiolitis during infancy. We enrolled 206 children during an initial episode of severe RSV bronchiolitis at 12 months of age or less in a prospective cohort study and followed these children for up to 6 years. In a subset of 81 children, we analyzed CCL5 (RANTES) mRNA expression in upper airway epithelial cells. Forty-eight percent of children had physician-diagnosed asthma before the seventh birthday. Independent determinants significantly associated with increased risk for physician-diagnosed asthma by the seventh birthday included maternal asthma (odds ratio [OR], 5.2; 95% CI, 1.7-15.9; P = .004), exposure to high levels of dog allergen (OR, 3.2; 95% CI, 1.3-7.7; P = .012), aeroallergen sensitivity at age 3 years (OR, 10.7; 95% CI, 2.1-55.0; P = .005), recurrent wheezing during the first 3 years of life (OR, 7.3; 95% CI, 1.2-43.3; P = .028), and CCL5 expression in nasal epithelia during acute RSV infection (OR, 3.8; 95% CI, 1.2-2.4; P < .001). White children (OR, 0.19; 95% CI, 0.04-0.93; P = .041) and children attending day care (OR, 0.18; 95% CI, 0.04-0.84; P = .029) had a decreased risk of physician-diagnosed asthma. Approximately 50% of children who experience severe RSV bronchiolitis have a subsequent asthma diagnosis. The presence of increased CCL5 levels in nasal epithelia at the time of bronchiolitis or the development of allergic sensitization by age 3 years are associated with increased likelihood of subsequent asthma.

Effect of Early Life Exposure to Air Pollution on Development of Childhood Asthma

BackgroundThere is increasing recognition of the importance of early environmental exposures in the development of childhood asthma. Outdoor air pollution is a recognized asthma trigger, but it is unclear whether exposure influences incident disease. We investigated the effect of exposure to ambient air pollution in utero and during the first year of life on risk of subsequent asthma diagnosis in a population-based nested case–control study.MethodsWe assessed all children born in southwestern British Columbia in 1999 and 2000 (n = 37,401) for incidence of asthma diagnosis up to 3–4 years of age using outpatient and hospitalization records. Asthma cases were age- and sex-matched to five randomly chosen controls from the eligible cohort. We estimated each individual’s exposure to ambient air pollution for the gestational period and first year of life using high-resolution pollution surfaces derived from regulatory monitoring data as well as land use regression models adjusted for temporal variation. We used logistic regression analyses to estimate effects of carbon monoxide, nitric oxide, nitrogen dioxide, particulate matter ≤ 10 μm and ≤ 2.5 μm in aerodynamic diameter (PM10 and PM2.5), ozone, sulfur dioxide, black carbon, woodsmoke, and proximity to roads and point sources on asthma diagnosis.ResultsA total of 3,482 children (9%) were classified as asthma cases. We observed a statistically significantly increased risk of asthma diagnosis with increased early life exposure to CO, NO, NO2, PM10, SO2, and black carbon and proximity to point sources. Traffic-related pollutants were associated with the highest risks: adjusted odds ratio = 1.08 (95% confidence interval, 1.04–1.12) for a 10-μg/m3 increase of NO, 1.12 (1.07–1.17) for a 10-μg/m3 increase in NO2, and 1.10 (1.06–1.13) for a 100-μg/m3 increase in CO. These data support the hypothesis that early childhood exposure to air pollutants plays a role in development of asthma.

Caesarean section delivery and the risk of allergic disorders in childhood

The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C-sections). To determine whether children born by C-section have a different risk of allergic disorders compared with those delivered vaginally. We also tested the hypothesis that the risk of allergic disorders is highest for children born after 'repeat C-sections'. A retrospective cohort study of 8,953 children aged 3-10 years. Children diagnosed with allergic rhinoconjunctivitis (AR), asthma, atopic dermatitis (AD), or food allergies were identified from the Kaiser Permanente Northwest Region electronic records. The children's sex, birth weight, birth order, postnatal exposure to antibiotics as well as the mothers' age, ethnicity, education, marital status, smoking status during pregnancy, and use of asthma or hayfever medications were identified through the mothers' medical records or through the Oregon Birth Registry. The risk of being diagnosed with AR was significantly higher in the children born by C-section than in those delivered vaginally: adjusted odds ratio (OR)=1.37%, 95% confidence interval (CI)=1.14-1.63. Delivery by C-section was also associated with the subsequent diagnosis of asthma (OR=1.24%, 95% CI=1.01-1.53); this association was gender specific, with a positive association restricted to girls (OR for asthma in girls: OR=1.53%, 95% CI=1.11-2.10; in boys: OR=1.08%, 95% CI=0.81-1.43). There was no significant association between mode of delivery and AD. If children born in a 'repeat C-section' were considered separately the risk of being diagnosed with AR increased further (OR=1.78%, 95% CI=1.34-2.37). The same increase was noted for asthma in girls (OR=1.83%, 95% CI=1.13-2.97) but not in boys. Caesarean sections may be associated with an increased risk of developing AR in childhood.

Early childhood respiratory symptoms and the subsequent diagnosis of asthma

Background: Respiratory symptoms are frequent in very young children, and the relation of these symptoms to later asthma in some of these children is unknown. Objective: The aim of the study was to describe the natural history of respiratory symptoms in a community-based sample of young children who were prospectively observed for as long as 11 years. Methods: Subjects were participants in the Tucson Epidemiologic Study of Airways Obstructive Disease. They were under 5 years of age at enrollment and were studied by means of a parent-administered mail survey instrument every 1 to 2 years for 3 to 11 years. Results: Among subjects younger than 1 year of age, no single respiratory symptom, such as cough or wheeze only with colds, significantly increased the risk of a subsequent diagnosis of asthma. Among 1- and 2-year-olds, however, those with wheeze only with colds and those with attacks of shortness of breath with wheeze were more likely to be diagnosed with asthma later when compared with children without those symptoms (odds ratio = 2.1; p < 0.05 for wheeze only with colds). At ages 3 to 4 years, symptoms were even more strongly associated with subsequent asthma (odds ratio = 7.2; p < 0.0001 for attacks of shortness of breath with wheeze). Conclusion: Although respiratory symptoms reported by parents very early in life are not significantly associated with future asthma, those symptoms that begin at or persist through ages 3 to 4 years are. (J A LLERGY C LIN I MMUNOL 1996;98:48-54.)

Antecedent features of children in whom asthma develops during the second decade of life

In this report we compare 36 subjects in whom asthma was first diagnosed between the ages of 10 and 20 with 297 control subjects. All subjects were studied at age 5 to 9. Among the subjects who acquired a new diagnosis of asthma (NDA), the diagnosis was usually preceded by lower respiratory tract symptoms (31 of the 36 subjects had respiratory symptoms or a diagnosis of rhinitis or chronic bronchitis before asthma developed). Among those tested, more of those with NDA had positive allergy skin test results (56.5%) before diagnosis than control subjects (29.6%; p < 0.05), and the subjects with NDA had higher levels of serum IgE than control subjects (mean log serum IgE = 2.27 in subjects with NDA, 1.76 in control subjects; p < 0.05). Pulmonary function tests revealed no significant differences in the groups before diagnosis. Using logistic regression, we determined that wheezing, cough, a diagnosis of chronic bronchitis, and a positive allergy skin test result were independent risk factors for asthma. When combinations of variables were used, subjects with wheezing and a positive allergy skin test result, cough and a positive test result, and also those with a prior diagnosis of chronic bronchitis alone were at highest risk of a subsequent diagnosis of asthma.

Findings before diagnoses of asthma among the elderly in a longitudinal study of a general population sample

Forty elderly subjects who denied ever having asthma or emphysema on enrollment in a longitudinal epidemiologic study later reported consulting a doctor for asthma when they were older than 60 years of age. The average age at which the diagnosis was reported was 70.8 years, after a mean follow-up of 8.5 years. Findings on enrollment in the newly diagnosed subjects with asthma are compared with findings in the 1145 subjects who provided follow-up information when they were older than age 60 years but had never developed asthma. At the time of enrollment, most subjects later diagnosed as having asthma already had wheezing symptoms, suggesting at least a mild asthmatic state, and many subjects had impaired ventilatory function, a positive allergy skin test (especially in association with rhinitis), and blood eosinophilia. Thirty-five percent of the subjects recalled “respiratory trouble before age 16” despite denying prior asthma. The likelihood of a new asthma label was very closely related to the age-sex-standardized serum-IgE level before diagnosis. Newly diagnosed subjects with asthma demonstrated much greater rates of decline in FEV 1 than control subjects or than subjects who already had known asthma on enrollment. We conclude that (1) symptoms suggesting asthma are usually present for many years before the diagnosis of the disease in elderly subjects, (2) the serum-IgE level is closely related to the likelihood of a subsequent asthma diagnosis, even in this age group, and (3) a rapid fall in lung function often occurs around the time of initial diagnosis.