Objective: To determine the prevalence of and the risk factors for wheezing in infants under one year of age and residing in the city of Porto Alegre, Brazil. Methods: This was a cross-sectional study and is part of a multicenter, multinational project. The parents or legal guardians of the infants were interviewed at primary health care clinics or during home visits. We used a standardized questionnaire, validated for use in Brazil. Potential risk factors were assessed by means of a Poisson regression model with robust variance estimation, using the Wald test to determine the significance of each variable in the model. Results: The sample comprised 1,013 infants. The majority of those were male (53%), and the mean age was 13.5 ± 1.2 months. In 61% of the infants, there had been at least one episode of wheezing, which had recurred at least three times in one third of those infants. The mean age at the first episode of wheezing was 5.16 months (median, 5 months). Over 40% of the infants with wheezing visited emergency rooms due to wheezing, and 17% of those were hospitalized at least once in the first year of life because of this symptom. In the multivariate analysis, the risk factors for wheezing were as follows: male gender; history of pneumonia; maternal smoking during pregnancy; day care center attendance; low maternal level of education; early weaning; multiple episodes of cold; first viral infection prior to 3 months of age; existence of siblings; and history of asthma in the nuclear family. Conclusions: The prevalence of wheezing is high among infants in the city of Porto Alegre. We identified various risk factors for wheezing in infants.

Keywords: Respiratory sounds/epidemiology; Asthma; Infant; Risk factors.

Objective: To determine, in a sample of infants, the prevalence of and risk factors for occasional wheezing (OW) and recurrent wheezing-wheezy baby syndrome (WBS). Methods: Parents of infants (12-15 months of age) completed the International Study of Wheezing in Infants questionnaire. Results: We included 1,269 infants residing in the city of Blumenau, Brazil. Of those, 715 (56.34%) had a history of wheezing, which was more common among boys. The prevalences of OW and WBS were 27.03% (n = 343) and 29.31% (n = 372), respectively. On average, the first wheezing episode occurred at 5.55 ± 2.87 months of age. Among the 715 infants with a history of wheezing, the first episode occurred within the first six months of life in 479 (66.99%), and 372 (52.03%) had had three or more episodes. Factors associated with wheezing in general were pneumonia; oral corticosteroid use; a cold; attending daycare; having a parent with asthma or allergies; mother working outside the home; male gender; no breastfeeding; and mold. Factors associated with WBS were a cold; physician-diagnosed asthma; ER visits; corticosteroid use; pneumonia; bronchitis; dyspnea; attending daycare; bronchodilator use; having a parent with asthma; no breastfeeding; mother working outside the home; and a dog in the household. Conclusions: The prevalence of wheezing in the studied population was high (56.34%). The etiology was multifactorial, and the risk factors were intrinsic and extrinsic (respiratory tract infections, allergies, attending daycare, and early wheezing). The high prevalence and the intrinsic risk factors indicate the need and the opportunity for epidemiological and genetic studies in this population. In addition, mothers should be encouraged to prolong breastfeeding and to keep infants under six months of age out of daycare.

Keywords: Asthma; Prevalence; Risk factors.

Objective: To determine the prevalence and severity of wheezing in infants, using the standardized protocol devised for the "Estudio Internacional de Sibilancias en Lactantes" (EISL, International Study of Wheezing in Infants), as well as to determine the relationship between such wheezing and physician-diagnosed asthma, in the first year of life. Methods: Between March of 2005 and August of 2006, the EISL questionnaire was administered to the parents or legal guardians of infants undergoing routine procedures or immunization at public primary health care clinics in the southern part of the city of São Paulo, Brazil. Results: Our sample comprised 1,014 infants (mean age = 5.0 ± 3.0 months), 467 (46.0%) of whom had at least one wheezing episode, 270 (26.6%) having three or more such episodes, in their first year of life. The use of inhaled β2 agonists, inhaled corticosteroids, or antileukotrienes, as well as the occurrence of nocturnal symptoms, difficulty breathing, pneumonia, emergency room visits, and hospitalization due to severe wheezing, was significantly more common among those with recurrent wheezing (p < 0.05). Physician-diagnosed asthma was reported for 35 (7.5%) of the 467 wheezing infants and was found to be associated with the use of inhaled corticosteroids, difficulty breathing during the attacks, and six or more wheezing episodes in the first year of life. However, less than 40% of those infants were treated with inhaled corticosteroids or antileukotrienes. Conclusions: In this study, the prevalence of wheezing episodes among infants in their first year of life was high and had an early onset. The proportion of infants diagnosed with and treated for asthma was low.

Keywords: Asthma/diagnosis; Asthma/epidemiology; Respiratory sounds.

Objective: To determine the prevalence of vitamin D deficiency/insufficiency in children 0-18 years of age with recurrent wheezing and/or asthma residing in the microregion of Viçosa, Minas Gerais, Brazil, and treated at a referral center, and to determine its association with major risk factors for wheezing. Methods: A cross-sectional study was performed using a semi-structured questionnaire, which was administered by trained interviewers to the legal guardians of the study participants. Data were obtained regarding general characteristics of recurrent wheezing; general sociodemographic, environmental, and biologic factors; and atopy-related factors. The magnitude of the statistical association was assessed by calculating ORs and their corresponding 95% CIs by using multiple logistic regression. Results: We included 124 children in the study. The prevalence of vitamin D deficiency/insufficiency in the sample was 57.3%. Vitamin D deficiency/insufficiency was found to be associated with wheezing in the first year of life, personal history of atopic dermatitis, environmental pollution, and vitamin D supplementation until 2 years of age. Conclusions: The prevalence of vitamin D deficiency/insufficiency was high in our sample. Vitamin D concentrations were directly associated with vitamin D supplementation until 2 years of age and were inversely associated with wheezing events in the first year of life, personal history of atopic dermatitis, and environmental pollution.

Keywords: Vitamin D; Asthma; Respiratory sounds; Minors.

Objective: To assess nicotine product use among incoming students at public and private universities in Brazil. Methods: This was a multicenter cross-sectional study including a convenience sample of incoming university students (= 18 years of age). Current use of conventional cigarettes, electronic cigarettes, and other nicotine products, as well as indicators of dependence and knowledge of the consequences of active use of or passive exposure to nicotine products were investigated with the use of a 38-item questionnaire. Descriptive statistics were used to analyze the data. Results: A total of 863 students completed the questionnaire. Of those, most (61%) were female, and most (76.6%) identified themselves as White. In addition, most (86%) were in the 18- to 24-year age bracket, and most (88.6%) attended a public university. In the past 30 days, 20.7% reported using electronic cigarettes, 23.2% reported using conventional cigarettes, and more than 50% reported using other nicotine products. More than 80% agreed that electronic cigarettes are harmful to health and are as damaging as other types of smoking. Over half of the respondents reported using the product shortly after waking up, and, paradoxically, 81% stated that they would quit whenever they wanted. Passive exposure was reported by 21.6%, occurring at home (in 33.6%), in other indoor environments (in 41.7%), and in open environments (in 87.5%). Conclusions: Experimentation and current use of nicotine products are high among incoming students at public and private universities in Brazil. Passive exposure to nicotine products is commonplace. Advanced communication tools are needed, particularly to emphasize the dangers of nicotine dependence. Being a legal drug, nicotine is often perceived as harmless, reinforcing the misconception that it can be used without consequences.

Keywords: Cigarette smoking; Electronic nicotine delivery systems; Tobacco use disorder; Tobacco smoke pollution.

Objective: To evaluate symptoms, lung function, and quality of life of a cohort of patients hospitalized for severe COVID-19 12 months after hospital admission. Methods: This was a cross-sectional study. We included severe COVID-19 survivors hospitalized in one of three tertiary referral hospitals for COVID-19 in the city of Belo Horizonte, Brazil. Participants were submitted to lung function and six-minute walk tests and completed the EQ-5D-3L questionnaire. Results: The whole sample comprised 189 COVID-19 survivors (mean age = 59.6 ± 13.4 years) who had been admitted to a ward only (n = 96; 50.8%) or to an ICU (n = 93; 49.2%). At 12 months of follow-up, 43% of patients presented with dyspnea, 27% of whom had a restrictive ventilatory disorder and 18% of whom presented with impaired DLCO. There were no significant differences in FVC, FEV1, and TLC between the survivors with or without dyspnea. However, those who still had dyspnea had significantly more impaired DLCO (14.9% vs. 22.4%; p < 0.020) and poorer quality of life. Conclusions: After one year, survivors of severe COVID-19 in a middle-income country still present with high symptom burden, restrictive ventilatory changes, and loss of quality of life. Ongoing follow-up is needed to characterize long COVID-19 and identify strategies to mitigate its consequences.

Objective: To estimate the evolution of the prevalence of asthma and wheezing among schoolchildren in Brazil from 2012 to 2015, as well as to identify factors associated with both conditions. Methods: This was a cross-sectional study using data from the Brazilian National School-Based Adolescent Health Survey for 2012 and 2015. To characterize the evolution of the prevalence of asthma and wheezing, we used linear regression with weighted-least-squares estimation and presented the annual percent change (APC). Results: During the study period, there was a reduction in the prevalence of wheezing, from 23.2% in 2012 to 22.4% in 2015 (APC, −0.27). The prevalence of asthma increased from 12.4% in 2012 to 16.0% in 2015 (APC, 1.20). The increase in the prevalence of asthma was greatest in the southern region of the country (APC, 2.17). Having any history of smoking and having consumed alcohol in the last 30 days were factors that influenced the prevalence of wheezing and the prevalence of a self-reported diagnosis of asthma during the two years evaluated. Conclusions: There has been an increase in the prevalence of asthma in recent years in Brazil. Our data underscore the importance of improving health strategies and policies aimed at the control of asthma.

Keywords: Asthma/epidemiology; Respiratory sounds; Students.

Objective: To determine the prevalence of risk factors for obstructive sleep apnea syndrome in interstate bus drivers. Methods: This study involved 262 professional interstate bus drivers employed by a Brazilian company headquartered in the Federal District. The drivers were evaluated using a questionnaire designed to assess respiratory sleep disorders, the Epworth Sleepiness Scale, test of sustained attention, test of divided attention and anthropometric measurements. Results: Body weight was found to be above the ideal in 68% of the drivers evaluated, 34% of which had a neck circumference = 42 cm. During the study period, the drivers reported using tobacco (27%), cola-based soft drinks (55%), alcohol (65%) and coffee (88%). The Epworth Sleepiness Scale score was = 10 points in 28%. Snoring was reported by 36%, sleep apnea by 5%, a sensation of suffocation during sleep by 12%, restless sleep by 29% and drowsiness while driving by 48%. There were 42% who had been involved in transit accidents, 7.6% of which were attributed to hypersomnolence. Those scoring higher than 10 of the Epworth Sleepiness Scale presented lower levels of sustained attention. In addition, a reduction in divided attention was found to correlate with greater daytime sleepiness and larger neck circumference. Conclusion: The rate of stimulant use found in the group of drivers evaluated is alarming. The high prevalence of daytime sleepiness indicates that attentiveness is reduced in this population.

Keywords: Automobile driving; Sleep apnea, obstructive; Work schedule tolerance; Psychometrics; Risk factors; Attention; Questionnaires

Objective: To estimate the prevalence of primary resistance to the drugs in the basic treatment regimen for tuberculosis in treatment-naïve patients with pulmonary tuberculosis and no known risk factors for such resistance, as well as to identify factors potentially associated with drug resistance. Methods: This was an exploratory cross-sectional study. We analyzed the medical records of the subjects enrolled in two clinical trials of treatments for drug-susceptible tuberculosis between November 1, 2004 and March 31, 2011 at the Prof. Newton Bethlem Outpatient Clinic of the Federal University of Rio de Janeiro Thoracic Diseases Institute, located in the city of Rio de Janeiro, Brazil. The inclusion criteria were being ≥ 18 years of age, testing positive for AFB in the first sputum sample, having a positive culture for Mycobacterium tuberculosis, having undergone drug susceptibility testing, and being treatment-naïve. Patients with a history of imprisonment or hospitalization were excluded, as were those who had been in contact with drug-resistant tuberculosis patients. Results: We included 209 patients. The overall prevalence of primary drug resistance was 16.3%. The overall prevalence of resistance to isoniazid and streptomycin was, respectively, 9.6% and 9.1%, compared with 5.8% and 6.8% for single-drug resistance to isoniazid and streptomycin, respectively. The prevalence of resistance to two or more drugs was 3.8%, and the prevalence of multidrug resistance was 0.5%. No statistically significant associations were found between the variables studied and drug susceptibility testing results. Conclusions: In this sample, the prevalence of primary drug resistance was high despite the absence of known risk factors.

Keywords: Tuberculosis, pulmonary; Tuberculosis, multidrug-resistant; Risk factors.

Objective: To identify and classify risk factors for venous thromboembolism (VTE) in hospitalized patients, as well as to evaluate medical practices regarding prophylaxis for the disease. Methods: An observational cross-sectional study, carried out between January and March of 2006, involving inpatients at three hospitals in the city of Manaus, Brazil. Risk stratification for VTE was based on the criteria established by the Brazilian Society of Angiology and Vascular Surgery and by the International Union of Angiology. Clinical, surgical and medication-related risk factors were analyzed. The statistical analysis of the data obtained was conducted, adopting an alpha error of 5% and 95% CI. Qualitative data were analyzed using the chi-square test, whereas quantitative data were analyzed using Student's t-test. Results: Of the 1,036 patients included (total number of admissions, 1,051), 515 (49.7%) were male, and 521 (50.3%) were female. A total of 23 risk factors for VTE were identified (total number of occurrences, 2,319). The stratified risk for VTE was 50.6%, 16.6% and 30.8% among the admissions of high-, moderate- and low-risk cases, respectively. In 73.3% of the admissions, nonpharmacological prophylaxis was not employed at any point during the study period. In 74% of those classified as high- or moderate-risk cases, no prophylactic medications were administered. Conclusions: This study showed that, in the population studied, risk factors were common and that prophylactic measures were not employed in patients prone to developing VTE and its complications.

Keywords: Venous thromboembolism; Risk factors; Venous thrombosis/prevention & control.

Objective: To present the Programa Infantil de Prevenção de Asma (PIPA, Program for the Prevention of Childhood Asthma) and the characteristics of the patients followed in this program. Methods: Implemented in the city of Uruguaiana, Brazil, PIPA has as its target population children and adolescents (< 18 years of age) with asthma or suspected asthma. Patients either enroll in PIPA spontaneously or are referred by pediatricians or primary care physicians. In this retrospective study, we use a standardized protocol to assess PIPA patients. Results: By the end of the study period, 646 patients were being followed. Of those, 298 (46.1%) were ≤ 3 years of age. In this group of patients, recurrent wheezing was identified in 60.7%, and the first episode of wheezing occurred in the first six months of life in 86.0%. Severe wheezing was identified in 29.5% and 45.4% in the children ≤ 3 and > 3 years of age, respectively. Physician-diagnosed asthma was reported in 26.5% and 82.2%, respectively. In the sample as a whole, the prevalence of passive smoking was high (> 36%), occurring during pregnancy in > 15%; > 40% of the patients had been born by cesarean section; and 30% had a mother who had had < 8 years of schooling. Conclusions: A prevention program for children with asthma is an effective strategy for controlling the disease. Knowledge of local epidemiological and environmental characteristics is essential to reducing the prevalence of the severe forms of asthma, to improving the use of health resources, and to preventing pulmonary changes that could lead to COPD in adulthood.

Keywords: Asthma/prevention and control; Asthma/epidemiology; Patient care.

Objective: There is still limited information on the clinical characteristics and outcomes of cystic fibrosis (CF) patients with COVID-19 in Brazil. The objective of this study was to describe the cumulative incidence of COVID-19 in CF patients, as well as their clinical characteristics and outcomes. Methods: This was a prospective cohort study involving unvaccinated adult CF patients and conducted during the first year of the SARS-CoV-2 pandemic in the city of Porto Alegre, in southern Brazil. The clinical course of the disease was rated on the WHO Ordinal Scale for Clinical Improvement. The primary outcome was the number of incident cases of COVID-19. Results: Between April 30, 2020 and April 29, 2021, 98 CF patients were included in the study. Seventeen patients were diagnosed with COVID-19. For the CF patients, the annual cumulative incidence of COVID-19 was 17.3%, similar to that for the general population, adjusted for age (18.5%). The most common symptoms at diagnosis of COVID-19 were cough (in 59%), dyspnea (in 53%), fatigue (in 53%), and fever (in 47%). Only 6 (35%) of the patients required hospitalization, and 3 (17.6%) required oxygen support. Only 1 patient required mechanical ventilation, having subsequently died. Conclusions: During the first year of the SARS-CoV-2 pandemic in southern Brazil, the cumulative incidence rate of COVID-19 was similar between CF patients and the general population. More than 50% of the CF patients with SARS-CoV-2 infection had a mild clinical presentation, without the need for hospital admission, and almost the entire sample recovered completely from the infection, the exception being 1 patient who had advanced lung disease and who died.

Keywords: Cystic fibrosis; COVID-19; SARS-CoV-2.

This article reviews the effects of aging, tobacco-smoking, chronic bronchitis and emphysema, heart failure, oropharyngeal colonization, aspiration (micro and macro), alcoholism, hepatic cirrhosis, nutritional deficiency, immunosuppression, and environmental factors on the risk of community-acquired pneumonia and its severity. In the second part, the authors review the prophylactic action of anti-influenza and anti-pneumococcus vaccines as well as the role of prevention and treatment of antiviral agents in community-acquired pneumonia.

Keywords: Pneumococcal pneumonia. Influenza. Influenza vaccine. Viral vaccines. Risk factors.

Objective: Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation (MV). However, data on VAP in patients on prolonged MV (PMV) are scarce. We aimed to describe the characteristics of VAP patients on PMV and to identify factors associated with mortality. Methods: This was a retrospective cohort study including VAP patients on PMV. We recorded baseline characteristics, as well as 30-day and 90-day mortality rates. Variables associated with mortality were determined by Kaplan-Meier survival analysis and Cox regression model. Results: We identified 80 episodes of VAP in 62 subjects on PMV. The medians for age, Charlson Comorbidity Index, SOFA score, and days on MV were, respectively, 69.5 years, 5, 4, and 56 days. Episodes of VAP occurred between days 21 and 50 of MV in 28 patients (45.2%) and, by day 90 of MV, in 48 patients (77.4%). The 30-day and 90-day mortality rates were 30.0% and 63.7%, respectively. There were associations of 30-day mortality with the SOFA score (hazard ratio [HR] = 1.30; 95% CI: 1.12-1.52; p < 0.001) and use of vasoactive agents (HR = 4.0; 95% CI: 1.2-12.9; p = 0.02), whereas 90-day mortality was associated with age (HR = 1.03; 95% CI: 1.00-1.05; p = 0.003), SOFA score (HR = 1.20; 95% CI: 1.07-1.34; p = 0.001), use of vasoactive agents (HR = 4.07; 95% CI: 1.93-8.55; p < 0.001), and COPD (HR = 3.35; 95% CI: 1.71-6.60; p < 0.001). Conclusions: Mortality rates in VAP patients on PMV are considerably high. The onset of VAP can occur various days after MV initiation. The SOFA score is useful for predicting fatal outcomes. The factors associated with mortality could help guide therapeutic decisions and determine prognosis.

Keywords: Pneumonia, ventilator-associated; Critical care; Ventilators, mechanical.

Objective: To identify, characterize, and quantify associations of various factors with quality of life (QoL) in patients with asthma, according to the pharmacotherapy employed. Methods: This was a cross-sectional study involving 49 patients (≥ 18 years of age) with severe uncontrolled or refractory asthma treated at a specialized outpatient clinic of the Brazilian Unified Health Care System, regularly using high doses of inhaled corticosteroids (ICs) or other medications, and presenting comorbidities. At a single time point, QoL was assessed with the Asthma Quality of Life Questionnaire (AQLQ). The overall AQLQ score and those of its domains were correlated with demographic variables (gender and age); Asthma Control Questionnaire score; pharmacotherapy (initial IC dose, inhaler devices, and polytherapy); and comorbidities. Results: Better AQLQ scores were associated with asthma control-overall (OR = 0.38; 95% CI: 0.004-0.341; p < 0.001), "symptoms" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001), and "emotional function" domain (OR = 0.086; 95% CI: 0.016-0.476; p = 0.001)-and with IC dose ≤ 800 µg-"activity limitation" domain (OR = 0.249; 95% CI: 0.070-0.885; p = 0.029). Worse AQLQ scores were associated with polytherapy-"activity limitation" domain (OR = 3.651; 95% CI: 1.061-12.561; p = 0.036)-and number of comorbidities ≤ 5-"environmental stimuli" domain (OR = 5.042; 95% CI: 1.316-19.317; p = 0.015). Conclusions: Our results, the importance of this issue, and the lack of studies taking pharmacotherapy into consideration warrant longitudinal studies to establish a causal relationship between the identified factors and QoL in asthma patients.

Keywords: Asthma; Asthma/drug therapy; Quality of life; Medication therapy management.

Objective: To determine the prevalence of primary hyperhidrosis in the city of Botucatu, Brazil, and to evaluate how this disorder affects the quality of life in those suffering from it. Methods: A population survey was conducted in order to identify cases of hyperhidrosis among residents in the urban area of the city, selected by systematic cluster sampling. In accordance with the census maps of the city, the sample size should be at least 4,033 participants. Ten interviewers applied a questionnaire that evaluated the presence of excessive sweating and invited the subjects who reported hyperhidrosis to be evaluated by a physician in order to confirm the diagnosis. Results: A total of 4,133 residents, in 1,351 households, were surveyed. Excessive sweating was reported by 85 residents (prevalence = 2.07%), of whom 51 (60%) were female. Of those 85 respondents, 51 (60%) agreed to undergo medical evaluation to confirm the diagnosis and only 23 (45%) were diagnosed with primary hyperhidrosis (prevalence = 0.93%). Of the 23 subjects diagnosed with primary hyperhidrosis, 11 (48%) reported poor or very poor quality of life. Conclusions: Although the prevalence of self-reported excessive sweating was greater than 2%, the actual prevalence of primary hyperhidrosis in our sample was 0.93% and nearly 50% of the respondents with primary hyperhidrosis reported impaired quality of life.

Keywords: Hyperhidrosis/epidemiology; Hyperhidrosis/diagnosis; Quality of life.

Objective: To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD. Methods: Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees. Results: The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) = seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness. Conclusion: CHD, hsPDA, MV = seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

Keywords: BPD; Preterm infant; CHD; hsPDA;, Pneumonia; Mechanical ventilation

Objectives: To estimate the prevalence of allergic rhinitis (AR), atopic dermatitis (AD), and wheezing, and to describe their patterns of co-occurrence according to different characteristics in adolescence and early adulthood. Methods: Cross-sectional analyses from the 15-year and 22-year follow-ups of the 1993 Pelotas (Brazil) Birth Cohort. The outcomes were assessed based on self-reported data, and the patterns of co-occurrence were determined using cluster analysis. The sample was described using absolute and relative frequencies according to the independent variables. Venn diagrams were generated to visualize the co-occurrence of AR, AD, and wheezing. Results: Data on AR, AD, and wheezing were available for 4,286 participants at 15 years and 3,789 at 22 years. At 15 years, AR was reported by 20.9% of participants, AD by 25.2%, and wheezing by 33.4%. Meanwhile, at 22 years, AR was reported by 24.6%, AD by 14.2%, and wheezing by 30.7%. Notably, the overlap between AR and wheezing was greater than that of the other conditions (6.9% at 15 years and 8.3% at 22 years). Participants with lower maternal education and lower income were more likely to report having "no health condition". At 15 years, White individuals most frequently reported "three conditions" (4.1%; p<0.001), whereas at 22 years, they primarily reported "two conditions" (15.6%; p<0.001). The co-occurrence of all three health conditions was found to be greater than expected, with an observed rate 2.1 times higher (95% CI 1.4 - 3.0) at 22 years. Conclusions: This study highlights the social gradient in the diagnosis and reporting of co-occurrence of AR, AD, and wheezing

Keywords: asthma, wheezing, allergic rhinitis, atopic dermatitis, epidemiology