Asthma and poverty

Regulatory T-Cells During Pregnancy Relate to Women's Own Childhood History of Microbial Exposure

OBJECTIVES

Previous studies found that children with siblings, farm residence, and other proxies of greater microbial contacts had lower rates of hyper-responsive immune disorders. Yet, scientific debate persists regarding whether the human immune system is educated in early life primarily as a function of pathogenic or benign microbial exposures, or both. Furthermore, pregnancy relies on women's intrinsic immunosuppressive function, yet it remained unknown how immunoregulation in pregnant women relates to early-life microbial exposures. Here, we conduct a preliminary examination of whether childhood microbial exposures prime women's pregnancy-related immunoregulatory capacity.

METHODS

We administered retrospective questionnaires to estimate 55 pregnant women's early-life exposure to pathogenic (e.g., illness) and benign (e.g., pets; rural residence) microbes. Tolerogenic regulatory T-cells (Tregs) and Treg subtypes were measured by flow cytometry from peripheral blood.

RESULTS

Results show that proxies for both pathogenic and benign exposures were positively associated with Treg concentrations.

CONCLUSIONS

These findings offer insights that may help elucidate the relative contributions of early-life pathogenic ("hygiene hypothesis") and benign ("old friends hypothesis") microbial exposures toward the expansion of the Treg compartment. Human evolutionary history is characterized by changing microbial exposures as human residency patterns, living environments, and subsistence strategies changed. In this context, our findings suggest the possibility of less gestational pathology in human evolutionary past conditions typified by richer diversity of microbial exposure.

Sex and age characteristics of thunderstorm asthma emergency department visits

Severe asthma has been shown to occur in the combined presence of high pollen and thunderstorm conditions, also known as 'thunderstorm asthma.' First studied as severe epidemic events, recent longitudinal work studied less dramatic but more frequent occurrences. We explore thunderstorm asthma-related emergency department visits in the Minneapolis-St. Paul metropolitan area and evaluated risk differences by sex and age. We define a thunderstorm asthma exposure event as the daily occurrence of 2 or more lightning strikes during high pollen periods, and use daily counts of asthma-related emergency department visits to estimate relative and absolute risk of severe asthma during thunderstorm asthma events for the full population and for sex and age subgroups. The overall population had a 1.06 (95 % CI: 1.02, 1.09) times higher risk of asthma-related ED visits during thunderstorm asthma events compared to days without thunderstorm asthma events. Children under 18 show no higher risk (RR 1.02; 95 % CI: 0.97 1.08), but adults 18-44 years (RR 1.08; 95 % CI: 1.02, 1.13) and 45 and up (RR 1.08; 95 % CI 1.02, 1.15) show higher relative risk. Absolute risk measures show similar patterns to the age and sex results, but age-sex subgroups show more variation in absolute vs relative risk. Our results support an association between ED visits and thunderstorm asthma and provide evidence of varying risks by sex across the life course. These differences in risk have implications for clinical treatment of this allergic type of asthma and for future research into this poorly recognized environmental exposure. Plain Language Summary: Recent research has highlighted the existence of Thunderstorm asthma events, a phenomenon in which pollen grains rupture in the conditions that occur with a thunderstorm, releasing subpollen particles that are capable of triggering severe asthma in susceptible populations. Where severe asthma is a disease that usually impacts children, we find in this study that asthma ED visits associated with thunderstorm asthma events more frequently impact adults, particularly males 18-44 and females 45 and up.

Preschool children from lower household incomes experience inequality in asthma treatment: findings from a Danish nationwide cohort study

BACKGROUND

The obligation to pay for asthma medication in a country with universal healthcare might lead to increased asthma exacerbations and inequitable healthcare access for children from low-income households. Thus, the aim of this study was to examine the association between household income and childhood/preschool asthma regarding hospitalization and medication receipt.

METHODS

In this nationwide register-based cohort study, we encompassed all 3-year-old children residing in Denmark, born between 2000 and 2014, along with their linked parents and followed them until their sixth birthday. Household income was divided into quartiles. Asthma was categorized in two mutually exclusive groups as either the redemption of two prescriptions for asthma medication or receiving a hospital diagnosis. We utilized Poisson regression to estimate the risk ratio (RR).

RESULTS

The analysis included 834 422 preschool children. The prevalence of asthma dependent on medication alone was 7.3%, while 1.8% of children necessitated asthma-related hospitalization. Income inequality was evident across all income quartiles. Notably, children from the lowest income quartile had a RR of 0.95 (95% CI: 0.92-0.98) of redeeming asthma medication and conversely a RR of 1.18 (95% CI: 1.14-1.23) of asthma-related hospitalization.

CONCLUSIONS

Despite universal healthcare, income inequality has a dual impact on children from low-income households. They face a diminished risk of redeeming asthma medication and a higher susceptibility to asthma-related hospitalizations indicating an unequal access to healthcare. Prioritizing efforts to reduce childhood health inequalities is crucial. However, further research, particularly qualitative studies, is needed to better comprehend the underlying mechanisms to address the complexities of income inequality.

Sociodemographic inequities in unscheduled asthma care visits among public assistance recipients in Japan: additional risk by household composition among workers

BACKGROUND

Public assistance programs aim to prevent financial poverty by guaranteeing a minimum income for basic needs, including medical care. However, time poverty also matters, especially in the medical care adherence of people with chronic diseases. This study aimed to examine the association between the dual burden of working and household responsibilities, with unscheduled asthma care visits among public assistance recipients in Japan.

METHODS

This retrospective cohort study included public assistance recipients from two municipalities. We obtained participants' sociodemographic data in January 2016 from the public assistance database and identified the incidence of asthma care visits. Participants' unscheduled asthma visits and the frequency of asthma visits were used as the outcome variables. Unscheduled visits were defined as visits by recipients who did not receive asthma care during the first three months of the observation period. Participants' age, sex, household composition, and work status were used as explanatory variables. Multiple Poisson regression analyses were performed to calculate the cumulative incidence ratio (IR) with a 95% confidence interval (CI) of unscheduled visits across the explanatory variables. The effect of modification on the work status by household composition was also examined.

RESULTS

We identified 2,386 recipients at risk of having unscheduled visits, among which 121 patients (5.1%) had unscheduled visits. The multivariable Poisson regression revealed that the working recipients had a higher incidence of unscheduled visits than the non-working recipients (IR 1.44, 95% CI 1.00-2.07). Among working recipients, the IRs of unscheduled visits were higher among recipients cohabiting with adults (IR 1.90 95% CI 1.00-3.59) and with children (IR 2.35, 95% CI 1.11-4.95) than for recipients living alone. Among non-working recipients, the IRs of unscheduled visits were lower for recipients living with family (IR 0.74, 95% CI 0.41-1.35) and those living with children (IR 0.50, 95% CI 0.20-1.23). A higher frequency in asthma visits was observed among working recipients living with family.

CONCLUSIONS

Working adults cohabiting with children are at the greatest risk of unscheduled visits among adults receiving public assistance. To support healthy lifestyles of public assistance recipients, medical care providers and policymakers should pay special attention to the potentially underserved populations.

The Association of Food Insecurity With Asthma Control in Adults During COVID-19

BACKGROUND

Food insecurity has been associated with poorer asthma control in children, but research lacks in adults.

OBJECTIVE

To assess the frequency of food insecurity and its association with asthma control in adults during the coronavirus disease 2019 pandemic.

METHODS

An online cross-sectional survey study was conducted in US adults with asthma. Survey questions included how worried or concerned participants were about food security since the pandemic. Asthma control was assessed using the Asthma Control Test, with uncontrolled asthma defined as Asthma Control Test score less than or equal to 19. Self-report of food insecurity since the pandemic was assessed. Food insecurity variables were dichotomized into high insecurity (≥3) or low insecurity (<3). Descriptive statistics and bivariate analyses were performed.

RESULTS

Of the total participants (N = 866), 82.79% were female; mean age of participants was 44 ± 15.05 years, their mean Asthma Control Test score was 19.25 ± 4.54, and 18.48% had high food insecurity. Participants with high food insecurity were more likely to have uncontrolled asthma (74.38%) compared with those with lower food insecurity (34.99%; P < .01). The relationship between asthma control and food insecurity remained significant after adjusting for age, education, sex, race, anxiety, and living stability concerns due to the pandemic.

CONCLUSIONS

Food insecurity exists in adults with asthma and is associated with uncontrolled asthma. Providers should consider screening their patients for food insecurity when treating individuals with uncontrolled asthma.

Disadvantage in early-life and persistent asthma in adolescents: a UK cohort study

OBJECTIVE

To determine how early-life risk factors explain socioeconomic inequalities in persistent asthma in adolescence.

METHODS

We did a causal mediation analysis using data from 7487 children and young people in the UK Millennium Cohort Study. Persistent asthma was defined as having a diagnosis reported at any two or more time points at 7, 11 or 14 years. The main exposure was maternal education, a measure of early-life socioeconomic circumstances (SECs), used to calculate the relative index of inequality. We assessed how blocks of perinatal (maternal health behaviours, infant characteristics and duration of breastfeeding, measured at 9 months) and environmental risk factors (family housing conditions; potential exposure to infections through childcare type and sibling number, and neighbourhood characteristics, measured at 3 years) mediated the total effect of childhood SECs on persistent asthma risk, calculating the proportion mediated and natural indirect effect (NIE) via blocks of mediators.

RESULTS

At age 14 the overall prevalence of persistent asthma was 15%. Children of mothers with lower educational qualifications were more likely to have persistent asthma, with a clear social gradient (degree plus: 12.8% vs no qualifications: 20.3%). The NIE gives the effect of SECs acting only via the mediators and shows a 31% increased odds of persistent asthma when SECs are fixed at the highest level, and mediators at the level which would naturally occur at the lowest SECs versus highest SECs (NIE OR 1.31, 95% CI 1.04 to 1.65). Overall, 58.9% (95% CI 52.9 to 63.7) of the total effect (OR 1.70, 95% CI 1.20 to 2.40) of SECs on risk of persistent asthma in adolescence was mediated by perinatal and environmental characteristics.

CONCLUSIONS

Perinatal characteristics and the home environment in early life are more important in explaining socioeconomic inequalities in persistent asthma in British adolescents than more distal environmental exposures outside the home.

Thunderstorms, Pollen, and Severe Asthma in a Midwestern, USA, Urban Environment, 2007-2018

BACKGROUND

Previous research has shown an association between individual thunderstorm events in the presence of high pollen, commonly called thunderstorm asthma, and acute severe asthma events, but little work has studied risk over long periods of time, using detailed measurements of storms and pollen.

METHODS

We estimated change in risk of asthma-related emergency room visits related to thunderstorm asthma events in the Minneapolis-St. Paul metropolitan area over the years 2007-2018. We defined thunderstorm asthma events as daily occurrence of two or more lightning strikes during high pollen periods interpolating weather and pollen monitor data and modeling lightning counts. We acquired daily counts of asthma-related emergency department visits from the Minnesota Hospital Association and used a quasi-Poisson time-series regression to estimate overall relative risk of emergency department visits during thunderstorm asthma events.

RESULTS

We observed a 1.047 times higher risk (95% CI:1.012,1.083) of asthma-related emergency department visits on the day of thunderstorm asthma event. Our findings are robust to adjustment for temperature, humidity, wind, precipitation, ozone, PM2.5, day of week, and seasonal variation in asthma cases. Occurrence of lightning alone or pollen alone showed no association with risk of severe asthma. A two-stage analysis combining individual zip code level results shows similar RR and we see no evidence of spatial correlation or spatial heterogeneity of effect.

DISCUSSION

Our results support an association between co-occurrence of lightning and pollen and risk of severe asthma events. Our approach incorporates lightning and pollen data and small-spatial area exposure and outcome counts.

Impact of socioeconomic factors and house cleaning on asthma control in women

Background: It is known that socioeconomic factors affect various chronic diseases and also might affect asthma control. Exposure to house-cleaning products has been shown to impact both the onset and control of asthma. Objective: This study aimed to determine the effect of socioeconomic factors and house cleaning on asthma control of women with asthma. Methods: Adult women with asthma (N = 204) with informed consent were included in this single-center, cross-sectional observational study. A questionnaire, including items related to demographic, clinical, and socioeconomic features of the patients, was administered with a face-to-face interview by an investigator. A test to assess the level of asthma control was used to classify the patients as uncontrolled, partially controlled, and fully controlled. Wealth perception was measured with a visual analog scale. Investigated socioeconomic features were household size, monthly household income, education status, working status, occupation, and education status of the mothers of the patients. Results: Of the 204 adult female patients, 68.6% had uncontrolled, 14.7% had partially controlled, and 16.7% had fully controlled asthma. Partially or fully controlled asthma was higher (odds ratio [OR] 2.6 [95% confidence interval [CI], 1.09-6.22]) in the highest income quantile compared with the lowest income quantile. Asthma was better controlled in women with a visual analog scale score of wealth perception ≥ 7 (OR 1.93 [95% CI, 1.04-3.59]) and, in those who cleaned their houses, one to two times per week compared with zero times per week (OR 2.94 [95% CI, 1.19-7.26]). Conclusion: Having a higher household income was the only socioeconomic factor associated with better asthma control. After adjusting for age, duration of asthma, and comorbidities, better asthma control was significantly associated with cleaning the house one to two times a week.

Treatable Traits in Elderly Asthmatics from the Australasian Severe Asthma Network: A Prospective Cohort Study

BACKGROUND

Data on treatable traits (TTs) in different populations are limited.

OBJECTIVE

To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model.

METHODS

We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort.

RESULTS

A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection-induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection-induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance.

CONCLUSIONS

TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma.

Medical Neglect as a Contributor to Poorly Controlled Asthma in Childhood

Child maltreatment, including medical neglect, is a frequent contributor to the development of asthma as well as a barrier to its proper management. This article aims to review the role of medical neglect as a contributor to poor asthma control. Medical neglect can present as failure of the caretaker to recognize severe asthma symptoms in a child, non-adherence to medical management, failure to prevent chronic exposure to allergens or tobacco smoke, poor child nutrition leading to obesity, and allowing a young child to manage his/her illness without supervision. This article will explore the different factors leading to medical neglect (as illustrated by two cases) and suggest possible interventions aiming to prevent emergency department visits, hospitalizations, and asthma-related deaths.

The Impact of Social Determinants of Health on Children with Asthma

SzAsthma is the most common chronic disease of childhood. Disparities in asthma outcomes have led to international attention on the biologic, social, economic, and other factors that impact the health of children with asthma. Studies indicate that social determinants of health such as housing, neighborhood safety, and access to care significantly impact the health of children with asthma. However, screening for socioeconomic and environmental factors that impact asthma can be difficult to integrate into clinical practice. In addition, it is not yet clear which interventions to address these factors are most effective. This article will review recent studies of determinants and social determinants of health and propose a framework for identifying and addressing them in the care of children with asthma in a clinical setting.

Regional Variation of Hospitalization Rates for Asthma in Korea: Association with Ambient Carbon Monoxide and Health Care Supply

This study was performed to investigate the relationship between the hospitalization rate for asthma and the ambient carbon monoxide (CO) by examining regional variation of the hospitalization rates for asthma in Korea and its factors. The hospital inpatient claims for asthma were acquired from the National Health Insurance database in 2015. A multivariate linear regression was performed with the hospitalization rate for asthma as a dependent variable. The annual ambient concentration of CO showed a negative association with the hospitalization rates for asthma while that of sulfur dioxide showed a positive association. The number of primary care physicians showed a negative association with the hospitalization rates for asthma while the number of beds in hospitals with less than 300 beds showed a positive association. The negative association of the ambient concentration of CO with the hospitalization rates for asthma showed results upon further investigation.

Health care costs and resource utilization for different asthma severity stages in Colombia: a claims data analysis

BACKGROUND

Asthma is one of the most common chronic respiratory conditions worldwide. Asthma-related economic burden has been reported in Latin America, but knowledge about its economic impact to the Colombian health care system and the influence of disease severity is lacking. This study estimated direct medical costs and health care resource utilization (HCRU) in patients with asthma according to severity in Colombia.

METHODS

This study identified all-age patients who had at least one medical event linked to an asthma diagnosis (CIE-10: J45-J46) between 2004 and 2014. Patients were selected if they had a continuous enrollment and uninterrupted insurance coverage between January 1-2015 and December 31-2015 and were categorized into 4 different severity levels using a modified algorithm based on Leidy criteria. Healthcare utilization and costs were estimated in a 1-year period after the identification period. A Generalized Linear Model (GLM) with gamma distribution and log link was used to analyze costs adjusting for patient demographics.

RESULTS

A total of 20,410 patients were included: 69.5% had mild intermittent, 18.0% mild persistent, 6.9% moderate persistent and 5.5% severe persistent asthma; with mean costs (SD) of $67 (134), $482 (1506), $1061 (1983), $2235 (3426) respectively (p < 0.001). The mean total direct cost was estimated at $331 (1278) per patient. Medication and hospitalization had the higher proportion in total costs (46% and 31% respectively). General physician visits was the most used service (57.2%) and short-acting β-2 agonists the most used medication (24%).

CONCLUSIONS

Health services utilization and direct costs of asthma were highly related to disease severity. Nationwide health policies aimed at the effective control of asthma are necessary and would play an important role in reducing the associated economic impact.

The status of geo-environmental health in Mississippi: Application of spatiotemporal statistics to improve health and air quality

Data enabled research with a spatial perspective may help to combat human diseases in an informed and cost-effective manner. Understanding the changing patterns of environmental degradation is essential to help in determining the health outcomes such as asthma of a community. In this research, Mississippi asthma-related prevalence data for 2003-2011 were analyzed using spatial statistical techniques in Geographic Information Systems. Geocoding by ZIP code, choropleth mapping, and hotspot analysis techniques were applied to map the spatial data. Disease rates were calculated for every ZIP code region from 2009 to 2011. The highest rates (4-5.5%) were found in Prairie in Monroe County for three consecutive years. Statistically significant hotspots were observed in urban regions of Jackson and Gulf port with steady increase near urban Jackson and the area between Jackson and meridian metropolis. For 2009-2011, spatial signatures of urban risk factors were found in dense population areas, which was confirmed from regression analysis of asthma patients with population data (linear increase of R² = 0.648, as it reaches a population size of 3,5000 per ZIP code and the relationship decreased to 59% as the population size increased above 3,5000 to a maximum of 4,7000 per ZIP code). The observed correlation coefficient (r) between monthly mean O₃ and asthma prevalence was moderately positive during 2009-2011 (r = 0.57). The regression model also indicated that 2011 annual PM_2.5 has a statistically significant influence on the aggravation of the asthma cases (adjusted R-squared 0.93) and the 2011 PM_2.5 depended on asthma per capita and poverty rate as well. The present study indicates that Jackson urban area and coastal Mississippi are to be observed for disease prevalence in future. The current results and GIS disease maps may be used by federal and state health authorities to identify at-risk populations and health advisory.

Persistent variations in national asthma mortality, hospital admissions and prevalence by socioeconomic status and region in England

BACKGROUND

The UK-wide National Review of Asthma Deaths sought to identify avoidable factors from the high numbers of deaths, but did not examine variation by socioeconomic status (SES) or region.

METHODS

We used asthma deaths in England over the period 2002-2015 obtained from national deaths registers, summarised by quintiles of Index of Multiple Deprivation (IMD) and Government Office Region. Emergency asthma admissions were obtained from Hospital Episode Statistics for England 2001-2011. The prevalence of asthma was derived from the Health Survey for England 2010. Associations of mortality, admissions and prevalence with IMD quintile and region were estimated cross-sectionally using incidence rate ratios (IRRs) adjusted for age and sex and, where possible, smoking.

RESULTS

Asthma mortality decreased among more deprived groups at younger ages. Among 5-44 year olds, those in the most deprived quintile, mortality was 19% lower than those in the least deprived quintile (IRR 0.81 (95% CI 0.69 to 0.96). In older adults, this pattern was reversed (45-74 years: IRR 1.37 (1.24-1.52), ≥75 years: IRR 1.30 (1.22-1.39)). In 5-44 year olds the inverse trend with asthma mortality contrasted with large positive associations for admissions (IRR 3.34 (3.30-3.38)) and prevalence of severe symptoms (IRR 2.38 (1.70-3.33)). Prevalence trends remained after adjustment for smoking. IRRs for asthma mortality, admissions and prevalence showed significant heterogeneity between English regions.

CONCLUSIONS

Despite asthma mortality, emergency admissions and prevalence decreasing over recent decades, England still experiences significant SES and regional variations. The previously undocumented inverse relation between deprivation and mortality in the young requires further investigation.

Epidemiology of chronic respiratory diseases and associated factors in the adult Italian population

Background

Detailed epidemiology of Chronic Respiratory Diseases (CRDs) and of their risk and protective factors is needed to plan preventive interventions to reduce the burden of CRDs on population health. This study determines the prevalence of doctor-diagnosed CRDs and its associated factors in the adult Italian population.

Methods

Data was collected from adults participating in the ongoing cross-sectional Italian Behavioural Risk Factor Surveillance System (PASSI) between 2013 and 2015.

Results

Among 108 705 respondents, 7.0% reported a CRD (3.4% asthma, 2.6% COPD, 1.0% Asthma-COPD Overlap Syndrome). Current smoking was more frequent in the group with CRD compared to those without (30.8% vs. 25.2%, P < 0.001), as was physical inactivity (41.9% vs. 36.4%, P 0.009) and overweight/obesity (52.4% vs. 41.4%, P 0.009). Adults with CRDs also reported appropriate perception of insufficient physical activity and excessive body weight, adopted protective behaviours and received preventive interventions more often than those without CRDs.

Conclusions

Italian adults with CRDs are more likely to be exposed to aggravating factors but are also knowledgeable of their condition and amenable to behaviour change. Since effective interventions for modifying these factors are available, there is an opportunity to reduce the significant disease burden of CRDs through specifically targeted health promotion interventions.

Health care access, concentrated poverty, and pediatric asthma hospital care use in California's San Joaquin Valley: A multilevel approach

BACKGROUND

California's San Joaquin Valley is a region with a history of poverty, low health care access, and high rates of pediatric asthma. It is important to understand the potential barriers to care that challenge vulnerable populations.

OBJECTIVE

The objective was to describe pediatric asthma-related utilization patterns in the emergency department (ED) and hospital by insurance coverage as well as to identify contributing individual-level indicators (age, sex, race/ethnicity, and insurance coverage) and neighborhood-level indicators of health care access.

METHODS

This was a retrospective study based on secondary data from California hospital and ED records 2007-2012. Children who used services for asthma-related conditions, were aged 0-14 years, Hispanic or non-Hispanic white, and resided in the San Joaquin Valley were included in the analysis. Poisson multilevel modeling was used to control for individual- and neighborhood-level factors.

RESULTS

The effect of insurance coverage on asthma ED visits and hospitalizations was modified by the neighborhood-level percentage of concentrated poverty (RR = 1.01, 95% CI = 1.01-1.02; RR = 1.03, 95% CI = 1.02-1.04, respectively). The effect of insurance coverage on asthma hospitalizations was completely explained by the neighborhood-level percentage of concentrated poverty.

CONCLUSIONS

Observed effects of insurance coverage on hospital care use were significantly modified by neighborhood-level measures of health care access and concentrated poverty. This suggests not only an overall greater risk for poor children on Medi-Cal, but also a greater vulnerability or response to neighborhood social factors such as socioeconomic status, community cohesiveness, crime, and racial/ethnic segregation.

Persistent asthma phenotype related with late-onset, high atopy, and low socioeconomic status in school-aged Korean children

BACKGROUND

Treatment guidelines for asthma have been established based on asthma severity; there are limitations in the identification of underlying pathophysiology and prediction of prognosis in heterogeneous phenotypes of asthma. Although the complex interactions between environmental and genetic factors affect the development and progression of asthma, studies on asthma phenotypes considering environmental factors are limited. This study aimed to identify asthma phenotypes using latent class analysis including environmental factors in school-age children.

METHODS

We included 235 children (6-8 years) with parent-reported, physician-diagnosed asthma from the Children's HEalth and Environmental Research (CHEER) study, which is a 4-year prospective follow-up study with 2-year intervals. At every survey, pulmonary function tests, methacholine challenge tests and blood tests with questionnaire were conducted.

RESULTS

Four asthma phenotypes were identified. Cluster 1 (22% of children) was characterized by high prevalence of atopy and mild symptoms; subjects in cluster 2 (17%) consisted of less atopy and normal lung function, but intermittent troublesome; cluster 3 (29%) experienced late-onset atopic troublesome asthma with decreased lung function in combination with low socioeconomic status; and cluster 4 was associated with early-onset and less-atopic infrequent asthma.

CONCLUSIONS

Late-onset, high atopy, and low socioeconomic status are associated with troublesome persistent asthma phenotype in school-age children. Environmental factors might be implicated in the clinical heterogeneity of asthma. Asthma phenotypes considering diverse factors might be more helpful in the identification of asthma pathogenesis and its prevention.

Childhood wheezing, asthma, allergy, atopy, and lung function: different socioeconomic patterns for different phenotypes

Identifying preventable exposures that lead to asthma and associated allergies has proved challenging, partly because of the difficulty in differentiating phenotypes that define homogeneous disease groups. Understanding the socioeconomic patterns of disease phenotypes can help distinguish which exposures are preventable. In the present study, we identified disease phenotypes that are susceptible to socioeconomic variation, and we determined which life-course exposures were associated with these inequalities in a contemporary birth cohort. Participants included children from the Avon Longitudinal Study of Parents and Children, a population-based birth cohort in England, who were born in 1991 and 1992 and attended the clinic at 7–8 years of age (n = 6,378). Disease phenotypes included asthma, atopy, wheezing, altered lung function, and bronchial reactivity phenotypes. Combining atopy with a diagnosis of asthma from a doctor captured the greatest socioeconomic variation, including opposing patterns between phenotype groups: Children with a low socioeconomic position (SEP) had more asthma alone (adjusted multinomial odds ratio = 1.50, 95% confidence interval: 1.21, 1.87) but less atopy alone (adjusted multinomial odds ratio = 0.80, 95% confidence interval: 0.66, 0.98) than did children with high SEP. Adjustment for maternal exposure to tobacco smoke during pregnancy and childhood exposure to tobacco smoke reduced the odds of asthma alone in children with a low SEP. Current inequalities among children who have asthma but not atopy can be prevented by eliminating exposure to tobacco smoke. Other disease phenotypes were not socially patterned or had SEP patterns that were not related to smoke exposure.

Prevalence of allergic rhinitis among adults in urban and rural areas of china: a population-based cross-sectional survey

Purpose

The aim of the present study was to compare the prevalence of self-reported and confirmable allergic rhinitis (AR) with positive skin prick test (SPT) results among adults living in urban and rural areas of China.

Methods

Adults from a community in Beijing and a village in Baoding were selected as representative urban and rural dwellers, respectively. All eligible residents were enrolled from the population register and received a face-to-face interview using modified validated questionnaires. Equal sets of randomly selected self-reporting AR-positive and AR-negative participants who responded to the questionnaires were also investigated using skin prick tests.

Results

A total of 803 participants in the rural area and a total of 1,499 participants in the urban area completed the questionnaires, with response rates being 75.9% and 81.5% respectively. The prevalence of self-reported AR of the rural area (19.1%) was significantly higher than that of the urban area (13.5%). The elementary school of educational level increased the risk of having AR (adjusted OR=2.198, 95% CI=1.072-2.236) .The positive SPT rates among subjects with self-reported AR in the rural and urban areas were 32.5% and 53.3%, respectively; the confirmable AR prevalence of 6.2% and 7.2% among the rural and urban adults, respectively.

Conclusions

The prevalence of confirmable AR is similar between rural and urban areas in China, although there is a higher prevalence of self-reported AR in the former.

Parental socioeconomic status, childhood asthma and medication use--a population-based study

Background

Little is known about how parental socioeconomic status affects offspring asthma risk in the general population, or its relation to healthcare and medication use among diagnosed children.

Methods

This register-based cohort study included 211,520 children born between April 2006 and December 2008 followed until December 2010. Asthma diagnoses were retrieved from the National Patient Register, and dispensed asthma medications from the Prescribed Drug Register. Parental socioeconomic status (income and education) were retrieved from Statistics Sweden. The associations between parental socioeconomic status and outcomes were estimated by Cox proportional hazard regression.

Results

Compared to the highest parental income level, children exposed to all other levels had increased risk of asthma during their first year of life (e.g. hazard ratio, HR 1.19, 95% confidence interval, CI 1.09–1.31 for diagnosis and HR 1.17, 95% CI 1.08–1.26 for medications for the lowest quintile) and the risk was decreased after the first year, especially among children from the lowest parental income quintile (HR 0.84, 95% CI 0.77–0.92 for diagnosis, and HR 0.80, 95% CI 0.74–0.86 for medications). Further, compared to children with college-educated parents, those whose parents had lower education had increased risk of childhood asthma regardless of age. Children with the lowest parental education had increased risk of an inpatient (HR 2.07, 95% CI 1.61–2.65) and outpatient (HR 1.32, 95% CI 1.18–1.47) asthma diagnosis. Among diagnosed children, those from families with lower education used fewer controller medications than those whose parents were college graduates.

Conclusions

Our findings indicate an age-varying association between parental income and childhood asthma and consistent inverse association regardless of age between parental education and asthma incidence, dispensed controller medications and inpatient care which should be further investigated and remedied.

Prevalence of asthma and allergies in children from the Greek-Cypriot and Turkish-Cypriot communities in Cyprus: a bi-communal cross-sectional study

Background

The Greek-Cypriot (G/C) and Turkish-Cypriot (T/C) communities have lived apart since 1974, with the former presumably adopting a more westernized way of life. We estimated the prevalence of asthma and allergies among children in the two communities and investigated differences in socio-demographic and lifestyle risk factors.

Methods

The ISAAC questionnaire was completed by 10156 children aged 7–8 and 13–14 years. Relative differences in asthma and allergic symptoms between the two communities were expressed as odds ratios (OR), estimated in multivariable logistic regression models before and after adjusting for participants’ risk characteristics.

Results

In contrast to our original speculation, consistently lower prevalence rates were observed for respiratory outcomes (but not eczema) among G/C compared to T/C children in both age-groups. For instance, the prevalence of current wheeze among 7–8 year-olds was 8.7% vs 11.4% (OR = 0.74, 95%, CI: 0.61, 0.90) and of current rhinoconjuctivitis 2.6% vs 4.9% (OR = 0.52, 95% CI: 0.37, 0.71). Surprisingly, the proportion reporting family history of allergy was almost double in the G/C community. With the exception of early life nursery attendance, several protective factors were more prevalent amongst T/C, such as bedroom sharing, less urbanized environment and exposure to farm animals. In contrast, exposure to tobacco smoke was more frequent in the T/C community. Controlling for risk factors did not account for the observed lower prevalence of current wheeze (in the younger age-group) and rhinoconjuctivitis (in both age-groups) among G/C children while differences in the prevalence of eczema between the two communities were no longer statistically significant.

Conclusions

A mixed picture of potential risk factors was observed in the two communities of Cyprus, not consistently favoring one over the other community since, for example, bedroom sharing and rural living but also exposure to tobacco smoke were more common among T/C children. Investigated risk factors do not fully account for the lower prevalence of asthma and allergies among G/C children, especially against a background of higher family history of allergy in this community.

Asthma care in resource-poor settings

Asthma prevalence in low- to middle-income countries is at least the same or higher than in rich countries, but with increased severity. Lack of control in these settings is due to various factors such as low accessibility to effective medications, multiple and uncoordinated weak infrastructures of medical services for the management of chronic diseases such as asthma, poor compliance with prescribed therapy, lack of asthma education, and social and cultural factors. There is an urgent requirement for the implementation of better ways to treat asthma in underserved populations, enhancing the access to preventive medications and educational approaches with modern technological methods.

Asthma in a primary health care center serving a poor population: a descriptive and interventional study

Asthma is a common chronic disease. Due to difficulties in accessibility to the health care system, asthma affects severely to minorities. This study's objective is to describe the morbidity of asthma on a poor population and its modification after abolishing assistance barriers.

Thirty-four asthma camps were carried out between May 2004 and May 2007. Patients' socioeconomic conditions, asthma history, and symptoms in the last month were determined during the camps. Patients received free medication and were invited to come to follow-up. Fifty-six children younger than 12 years old and 53 adults with persistent asthma were evaluated in 783 visits. The mean monthly income per capita was US $28.57.

At baseline, 50% of children and 34.5% of adults received inhaled corticosteroids. After intervention, 92.7% children and 98.1% adults received inhaled corticosteroids. Treatment was associated with a significant reduction of daytime and nighttime symptoms, absences to school or work, and emergency room visits and admissions. Patients referred less interference and more control of their disease in their everyday life.

Our results suggest that this population receives an insufficient treatment of its asthma severity. For such population, moving specialized assistance to the primary health care center resulted in a better control of their illness.

Home/social environment and asthma profiles in a vulnerable community from Caracas: lessons for urban Venezuela?

BACKGROUND

Asthma is a significant public health problem in Venezuela affecting the predominantly urban and poor majority of the population. Information regarding home and the social environment, key elements in asthma, is found to be deficient in these deprived socioeconomic sectors. This study was carried out to depict a life with asthma in this context which has been served over the years by a National Asthma Control Program.

METHODS

A survey of families residing in a socioeconomically deprived community of Caracas was carried out with the assumption that this community reflects the image of a life with asthma emanating from our deprived urban areas. Home physical settings were inspected for the following items: moldy walls, floors, ceilings, windows, sewage, garbage disposal, running water, plumbing, electricity, telephone, construction debris, furniture, bathrooms, food storage, and home appliances. In addition, we also gathered information regarding smoking habits, fumes exposure, pets and/or animals, and sighting of roaches and/or rodents. The presence of people with asthma was observed and their status of control was assessed through the asthma control test (ACT). Comparisons were made between families with asthmatics and those without asthmatics.

RESULTS

Randomly, 242 of 750 families (32.26%) were surveyed, with "head of family" providing information (75.6%) on most occasions. No significant association was found with respect to the previously explored items in those families with or without the presence of asthmatics. Medically diagnosed asthma was found in 14.91%, with ACT scores of <19 points in two-thirds of these adults and asthmatic children. Asthmatics reported symptoms occurring mostly during the night and an almost exclusive use of rescue medications. Families provided most treatments and children preferred to use the oral route for control medications. Significant work and school absenteeism were detected in more than 50% of these asthmatics.

CONCLUSIONS

No physical home environmental/risk factors turned out to be significantly associated with families reporting the presence of asthmatics. The high impact of asthma found in this Caracas slum underscores the realities of Venezuela's impoverished urban majority. To properly address this important challenge, our National Asthma Control Program needs to be reassessed.

Association between Household Income and Asthma Symptoms among Elementary School Children in Seoul

OBJECTIVES

This study examined the association between socioeconomic factors and asthma symptoms.

METHODS

A total of 6,919 elementary school children in Seoul were enrolled in the study. Data were obtained from a web-based questionnaire survey. The questionnaire was based on the International Study of Asthma and Allergies in Childhood core module. The prevalence of wheeze in the past 12 months and severe asthma symptoms were obtained. The potential risk factors for asthma symptoms included household income and the number of siblings. A multiple logistic regression analysis was used to calculate the odds ratios (OR) and 95% confidence interval (CI) for the risk factors of asthma symptoms.

RESULTS

The prevalence of current wheeze (wheeze in the past 12 months) was 5.2%. Household income and asthma symptoms were inversely associated after adjusting for other potential risk factors (p for trend=0.03). This association was modified by the number of siblings. With two or more siblings, the effect of household income on asthma symptoms was not significant. However, low household income was still a significant variable for patients with fewer than two siblings (OR 1.41; 95% CI, 1.09-1.81).

CONCLUSIONS

It appears that childhood asthma disparity is dependent on household income. Therefore, policies to improve childhood health inequities should be emphasized.

Longitudinal patterns of poverty and health in early childhood: exploring the influence of concurrent, previous, and cumulative poverty on child health outcomes

Background

Although the links between poverty and health have often been studied , the dynamics of poverty and physical health in early childhood remain under-investigated. In particular, it is not known whether the health of young children is affected differently from that of adults by patterns of poverty unique to them.

Methods

We examined patterns of health from 5 to 41 months of age as a function of concurrent, lagged, and chronic exposure to insufficient income. Using data from the first four rounds of the Quebec Longitudinal Study of Child Development, we performed multilevel logistic and multilevel Poisson regressions and latent growth curve analyses to explore associations between exposure to poverty and mother-reported asthma-like attacks, and maternal perception of health status controlling for neonatal, maternal, and environmental characteristics.

Results

The mean number of mother-reported asthma-like attacks significantly decreased as children aged. The likelihood of being perceived in a poorer health status also decreased across time. Concurrent poverty was associated with more mother-reported asthma-like attacks and with a higher risk of being perceived in poorer health status. One-period-lagged poverty was associated with more mother-reported asthma-like attacks and this remained significant after controlling for concurrent poverty. The number of mother-reported asthma-like attacks was significantly higher among children in the chronic poverty class compared to those in the never-poor class, particularly at 17 and 29 months. Perceived health status at 5-months was significantly poorer among chronically poor children compared to never-poor children.

Conclusion

Exposure to poverty negatively affects two major health indicators in early childhood – maternal perception of child health and mother-reported asthma-like attacks. Patterns of the effects vary according to timing and duration of poverty exposure. Further longitudinal research is warranted to disentangle time-specific from cumulative effects of poverty on child health.

Novel severe wheezy young children phenotypes: boys atopic multiple-trigger and girls nonatopic uncontrolled wheeze

BACKGROUND

Recurrent wheezing during infancy is a heterogeneous disorder that has been associated with early-onset asthma.

OBJECTIVE

To identify phenotypes of severe recurrent wheezing and therapeutic approaches.

METHODS

We performed cluster analysis with 20 variables of 551 children with active asthma, younger than 36 months old, and enrolled in the Trousseau Asthma Program.

RESULTS

We identified 3 independent clusters of children with wheezing. Cluster 1, mild episodic viral wheeze (n= 327), consisted of children with wheezing related only to colds (71%), mild disease (76%), and mainly normal chest x-ray results. Cluster 2, nonatopic uncontrolled wheeze (n = 157), was characterized by moderate to severe disease (91%), uncontrolled wheezing despite high doses of inhaled corticosteroids (55%), parents with asthma, and increased levels of ferritine. Cluster 3, atopic multiple-trigger wheeze (n = 67), included more children with multiple-trigger wheeze (68%) than did clusters 1 or 2; eczema (75%); a positive result from the Phadiatop Infant test (90%); increased levels of IgE, IgA, and IgG; and abnormal results from chest x-rays. In separate analysis, 1 parameter for boys (increased total level of IgE) and 2 parameters for girls (wheezing severity and increased total level of IgE) properly classified 90% of boys and 83% of girls in the appropriate cluster. Significant associations were found between overcrowding, molds and cockroaches at home, and atopic multiple-trigger wheeze and between day-care attendance and nonatopic uncontrolled wheeze in other parts.

CONCLUSION

We identified different phenotypes of recurrent wheezing in young children by using cluster analysis with usual variables. These phenotypes require confirmation in longer, follow-up studies.

Risk factors for asthma onset between the ages of 12 and 40. Results of the FENASMA study

OBJECTIVES

To describe the clinical profile of patients with asthma and to identify possible risk factors for its development in subjects over the age of 12.

PATIENTS AND METHODS

A multicenter study of cases and controls. Recruited for inclusion were case subjects between the ages of 12 and 40 diagnosed with asthma, with an onset of symptoms after the age of 12. Control subjects were selected, with ages between 12 and 40, who did not have childhood asthma and did not present symptoms of asthma at the time of the study.

RESULTS

We evaluated 923 subjects: 247 cases and 671 controls. 54.9% were women. Mean age of the cases was 28.3 ± 8.2; mean age of controls was 30.8 ± 7.1 (p<0.001). In the logistic regression analysis, it was observed that the determining factors for the of the presence of asthma were hypersensitivity to animals or other allergens, presence of rhinitis, family history of asthma, occupational risk/exposure to irritants and the hypersensitivity/intolerance to NSAIDs. In said analysis, it was also demonstrated that age was a protection factor, as well as level of education.

CONCLUSIONS

The risk factors for the development of asthma at an adult age are hypersensitivity to animals or other allergens, rhinitis, family history of asthma, occupational risk/exposure to irritants and the hypersensitivity/intolerance to NSAIDs, while age and level of education are protection factors.

Comparative resource utilization in medicaid-eligible patients with asthma treated with fixed-dose fluticasone propionate/salmeterol or fluticasone propionate monotherapy

OBJECTIVE

The aim of this work was to compare rates of asthma-related health service utilization for Medicaid-eligible pediatric and adult patients with asthma treated with fixed-dose fluticasone propionate/salmeterol (FSC) or fluticasone propionate (FP) monotherapy.

METHODS

A retrospective, observational claims analysis was conducted with Medicaid enrollees aged ≥4 years with ≥1 diagnosis code for asthma and a prescription fill for FSC or FP between January 1, 2002, and November 1, 2005. The end date allowed a follow-up period of ≥60 days; Medicaid data were available through December 31, 2005, and were obtained from 2 sources: a large US-managed Medicaid provider affiliated with i3 Innovus, and the Thomson Medstat Marketscan (Ann Arbor, Michigan) Medicaid claims database. Patients were new or continuing users of asthma controllers, but were new users of FSC or FP. Outcome measures included postindex use of systemic corticosteroid drugs and short-acting β-agonists (SABAs), asthma-related utilization, and costs. Descriptive and multivariate techniques were used, adjusting for differences in baseline demographics and length of follow-up time in the study population. Patients were grouped into cohorts according to age: 4 to 17 or ≥18 years.

RESULTS

The final study population was 50,428 patients, including 30,071 patients (59.6%) aged <18 years and 20,357 patients (40.4%) aged ≥18 years. Mean number of days of follow-up was 290.4, and 55.1% of patients (n = 27,793) were followed for ≥1 year after the index date. Among those aged <18 years, FSC treatment was associated with decreased adjusted risk of asthma-related emergency department (ED) visits (adjusted hazard ratio [HR] = 0.917; 95% CI, 0.855-0.984) and combined ED/inpatient (IP) visits (HR = 0.922; 95% CI, 0.860-0.988). Among those aged ≥18 years, FSC treatment was associated with decreased adjusted risk of asthma-related ED visits (HR = 0.907; 95% CI, 0.849-0.969) and combined ED/IP visits (HR = 0.907; 95% CI, 0.850-0.968). FSC treatment was also associated with significantly fewer prescription fills for SABAs compared with FP treatment in both age groups (aged <18 years: incident rate ratio [IRR] = 0.960 [95% CI, 0.929-0.992]; aged ≥18 years: IRR = 0.950 [95% CI, 0.905-0.998]). Total mean (SD) unadjusted asthma costs were $579 ($2429) for FSC and $551 ($3151) for FP in the <18-year age group and were $1764 ($10,006) for FSC and $1512 ($5543) for FP in the ≥18-year age group.

CONCLUSION

In this retrospective database analysis, Medicaid-eligible patients who initiated FSC therapy experienced better asthma control compared with patients who initiated FP monotherapy, as measured by asthma-related ED/IP visits and use of SABAs.

Effect of area of residence on patterns of aeroallergen sensitization in atopic patients

BACKGROUND

An association with sensitization to inhaled allergens and allergic rhinitis and asthma has been established. A recent study concluded that the disparity in allergen sensitization might primarily be caused by environmental factors rather than genetic differences. The primary objective was to identify potential differences in sensitization among subjects with the same ethnicity in South India who reside in different environments.

METHODS

Five hundred forty-six patients presenting to a tertiary allergy center with allergic rhinitis and or asthma underwent evaluation using a structured questionnaire, skin-prick testing to common aeroallergens, and spirometry and were categorized according to area of residence.

RESULTS

The most common allergens causing sensitization were house-dust mite (range, 65-70%), trees (range, 52-56%), and cockroaches (range, 39-53%). There was lower risk of sensitization to cockroach allergens for subjects <21 years old living in suburban (odds ratio [OR], 0.32; 95% confidence interval [CI], 0.12-0.81) and rural environments (OR, 0.33; 95% CI, 0.11-0.96) compared with subjects <21 years old living in urban areas. There was higher risk of sensitization to fungi in subjects <21 years old living in suburban areas (OR, 1.51; 95% CI, 0.60-3.77) and rural environments (OR, 2.71; 95% CI, 0.98-7.48) compared with subjects <21 years old living in urban environments.

CONCLUSION

Sensitization patterns are similar in different areas of residence except in younger subjects. Sensitization to fungi was higher in younger subjects from the rural area and cockroach sensitization were higher in younger subjects from urban areas. Sensitization is an important precursor of clinical allergic disease and further studies to unravel the complex gene-environment interactions of aeroallergen sensitization in different environments are needed.

Risk factors for current wheezing and its phenotypes among elementary school children

BACKGROUND

Accumulating evidence suggests, asthma includes many phenotypes with varying clinical and prognostic features. Epidemiological surveys documented a number of environmental risk factors for the development of asthma and interestingly these differ between and within countries, suggesting that the differences may be related with the different distribution of asthma phenotypes. This study aimed to investigate risk factors of current wheezing (CW) and different wheezing phenotypes in elementary school children.

METHODS

Six thousand nine hundred sixty-three 9- to 11-year-old children of a previous multicenter survey where the methodology of the International Study of Asthma and Allergies in Childhood (ISAAC) Phase-II was used were analyzed. Wheezing phenotypes were defined as wheezing with rhinitis (RW), wheezing with rhinoconjunctivitis (RCW), atopic wheezing (AW), non-atopic wheezing (NAW), and frequent wheezing (FW) (≥4/year wheezing episodes).

RESULTS

The prevalence of CW was 15.8% and among these, 22.4%, 67.3%, 45.9%, 20.5%, and 79.5% were classified as FW, RW, RCW, AW, and NAW, respectively. History of parental asthma/allergic rhinitis, coexistence of other allergic diseases, presence of mold and dampness in the house lived during the first year of life and maternal smoking in pregnancy were found to be risk factors for most phenotypes (odds ratio (OR) ranged from 1.43 to 3.56). Number of household in the last year (OR = 1.14), prematurity (OR = 2.08), and duration of breastfeeding (OR = 1.02) per additional month were found to be risk factor for FW, AW, and RCW, respectively.

CONCLUSION

Beside common risk factors for the development of asthma and its phenotypes, certain risk factors appeared to play a role in the development of phenotypic characteristics of asthma. These findings support our hypothesis that each phenotype has not only different clinical characteristics but also has different roots.

Childhood body mass index and risk of asthma in adolescence: a systematic review

Asthma and obesity, both of which are considered global health issues, affect approximately 300 million individuals worldwide. The observation that asthma and obesity tend to increase in parallel may indicate a potential link between these two conditions. The aim of this systematic review of the literature was to investigate the relationship between childhood nutritional status and incidence or persistence of asthma during adolescence. The principal eligibility criteria for selection of articles were including longitudinal analysis, and which measured of exposure during childhood or adolescence and outcome during adolescence. The systematic search initially returned 1563 unique articles. After inspection of titles and reading the abstracts of these articles, we chose 27 for full reading. Of these, 10 were selected to be included in the present review. Of the 10 selected studies, eight showed positive associations between overweight/obesity and asthma. Of these, two were independent of sex, three were found only among men and another three only among women. The present study shows strong evidence that, although the role of sex is not clear, obesity precedes, and is associated with, the persistence and intensity of symptoms of asthma.

Caesarean sections and risk of wheezing in childhood and adolescence: data from two birth cohort studies in Brazil

Background

There is evidence from two meta-analyses that children born through caesarean section (C-section) may have an increased risk of developing asthma compared with those born through vaginal delivery.

Objective

To evaluate the association between mode of delivery and wheezing (current and persistent) in childhood and adolescence, in two birth cohort studies in Brazil.

Methods

The outcome variable was based on the International Study of Allergy and Asthma questionnaire, which collects information about wheezing within the 12 months before the interview. Persistent wheezing was defined when it was present in more than one follow-up at different ages, in the 1993 cohort. The questions were asked to mothers when children were aged 4 years (1993 and 2004 cohorts) and directly to cohort participants at 11 and 15 years (1993 cohort). Mode of delivery was collected by the research team of each cohort when children were born.

Results

Response rates in the last follow-up visit of the 1993 and 2004 cohorts were 85% and 92%, respectively. The prevalence of current wheezing increased from 20% to 28% at 4 years from 1993 to 2004; at 11 and 15 years, the prevalence was around 14% and 12%, in the 1993 cohort. The proportion of C-sections increased from 30.5% to 45% between 1993 and 2004. In each cohort, the prevalence of current wheezing was similar among children born through vaginal and C-section. The risk for persistent wheezing in the 1993 cohort was higher among girls born through C-section than boys.

Conclusion

Despite the increase in the proportion of C-section in two cohorts in Southern Brazil, we found no evidence of an association between mode of delivery and the subsequent risk of wheezing. Among girls, although there was no statistical significance, the risk was higher for those born by C-section, especially regarding persistent wheezing.

Wheeze in children: the impact of parental education on atopic and non-atopic symptoms

There is conflicting evidence for the relationship between parental socioeconomic position and their children's asthma. The aim of this study was to investigate relationships between parental education and respiratory symptoms in their children, distinguishing atopic and non-atopic symptoms. A cross-sectional survey among 3262 elementary school children (age 8-13) was performed; data on parental education were obtained for 3213 children. Parents completed a questionnaire on their child's allergic and respiratory symptoms, and potential explanatory variables including family history, indoor environment, and the child's medical history. Subsets of children were tested for atopy (n = 1983), lung function (n = 2325), and airway hyperresponsiveness (AHR) (n = 880). Logistic regression was used to assess relationships of health outcomes with parental education. A high parental education was associated with an increased risk of atopic sensitization to indoor allergens (OR 1.31, 95% CI 1.02; 1.69). Studied explanatory variables did not influence the relationship. In contrast, a high parental education protected children from wheeze (OR 0.77, 95% CI 0.61; 0.97). This only applied to non-atopic wheeze (OR 0.65, 95% CI 0.43; 0.99) and not to atopic wheeze (OR 0.89, 95% CI 0.60; 1.31). The protection from non-atopic wheeze in children of highly educated parents declined after adjustment for household smoking and breastfeeding (OR 0.96, 95% CI 0.58; 1.57). Similar results were observed for non-atopic and atopic rhinitis. We conclude that children from highly educated parents are protected from non-atopic respiratory symptoms, which is largely explained by a lower rate of household smoking and a higher rate of breastfeeding.

Association between socioeconomic status and the prevalence of asthma

BACKGROUND

The finding in some recent studies that the prevalence of asthma is higher in poor populations contradicts the hygiene theory, which claims that improved quality of life removes protective factors that prevent atopy.

OBJECTIVE

To determine whether socioeconomic status (SES) is associated with the prevalence of asthma in adolescents in Israel.

METHODS

The study sample consisted of 159,243 consecutive 17-year-old military recruits examined in the Israel Defense Forces. Relevant medical data were collected from the army's computerized database. The SES of the recruits was assessed according to the socioeconomic grade (by quintiles) assigned to their city or town of residence by the Israel Central Bureau of Statistics and by the number of children in the family.

RESULTS

Asthma was documented in 8.5% of the male recruits and in 6.7% of the female recruits. The prevalence of asthma increased with an increase in socioeconomic grade, from 3.7% for the lowest quintile to 8.8% for the highest (P < .001). Separate analysis of individuals from the Tel Aviv area showed that the prevalence of asthma ranged from 3.4% to 13.7% from the lowest to the highest socioeconomic quintiles (P < .001). In Israel, having a higher number of children in the family is associated with lower SES. There was an inverse relationship between number of children in the family and the prevalence of asthma: 8.7% in families with 1 or 2 children and 1.9% in families with 9 or more children.

CONCLUSIONS

High SES is associated with a relatively high prevalence of asthma in adolescents in Israel.

The relationship between socio-economic and geographic factors and asthma among Canada's Aboriginal populations

OBJECTIVES

To examine the prevalence, exacerbations and management of asthma among Canada's Aboriginal populations, and its relationship to socio-economic and geographic factors.

STUDY DESIGN

Secondary analysis of a national cross-sectional questionnaire survey.

METHODS

Data were collected in 2000 and 2001 through a survey of Aboriginal children and adults residing on- and off-reserve as part of the 2001 Aboriginal People's Survey (APS). The asthma related outcome variables - physician-diagnosed asthma, attack in past year and regular use of inhalants - were examined in relation to socio-economic and geographic factors such as income, education, housing and location of residence. Statistical analyses were based on weighted univariate and multivariate logistic regressions.

RESULTS

The results show variations in asthma diagnosis, attacks and inhalant use across geographic location, socio-economic and demographic characteristics. Geographic location was found to be significantly associated with asthma for both adults and children, with those living in the northern territories, on-reserve or rural locations being the least likely to be diagnosed. Geographic location and Aboriginal identity were also found to be significantly associated with asthma medication use.

CONCLUSIONS

While these findings may suggest a "healthier" population in more remote locations, they alternatively point to a general pattern of under-diagnosis, potentially due to poor health care access, as is typical in more remote locations.

Poverty and chronic illness in early childhood: a comparison between the United kingdom and Quebec

OBJECTIVES

Our goal was to examine the association between poverty, in the first and fourth years of life and cumulatively in the first and fourth years of life, and the health of children in the fourth year of life in the UK Millennium Cohort Study and in the Quebec Longitudinal Study of Child Development (QLSCD).

METHODS

Data from the UK Millennium Cohort Study of 14 556 children and from the QLSCD of 1950 children were analyzed. Comparable measures of poverty were households in receipt of the safety-net benefit: income support in the United Kingdom and social welfare in Quebec. Three parent-reported health indicators were examined: asthma attack, long-standing illness, and limiting long-standing illness by the fourth year of life. Associations were explored with logistic regression modeling controlling for child characteristics and maternal education.

RESULTS

Poverty only in the first year of life significantly increased the risk of asthma attacks and limiting long-standing illness in the fourth year of life among UK children; trends were in the expected direction in the QLSCD but did not reach statistical significance. Poverty in the fourth year of life only significantly increased the risk of all 3 outcomes for UK children but not for Quebec children. For children experiencing poverty in both the first and fourth years of life, the risks for all 3 outcomes also increased in the United Kingdom, whereas only the risk of limiting long-standing illness increased in Quebec. Adjustment for confounding had little effect on the increased risks associated with poverty.

CONCLUSIONS

These findings suggest that experience of poverty at various times in early childhood increases the risk of asthma attacks and chronic illness in the fourth year of life; however, they also indicate that poverty at different stages of the early childhood life course may have different effects on chronic illness in different country settings.

Transdisciplinary research strategies for understanding socially patterned disease: the Asthma Coalition on Community, Environment, and Social Stress (ACCESS) project as a case study

As we have seen a global increase in asthma in the past three decades it has also become clear that it is a socially patterned disease, based on demographic and socioeconomic indicators clustered by areas of residence. This trend is not readily explained by traditional genetic paradigms or physical environmental exposures when considered alone. This has led to consideration of the interplay among physical and psychosocial environmental hazards and the molecular and genetic determinants of risk (i.e., biomedical framing) within the broader socioenvironmental context including socioeconomic position as an upstream "cause of the causes" (i.e., ecological framing). Transdisciplinary research strategies or programs that embrace this complexity through a shared conceptual framework that integrates diverse discipline-specific theories, models, measures, and analytical methods into ongoing asthma research may contribute most significantly toward furthering our understanding of socially patterned disease. This paper provides an overview of a multilevel, multimethod longitudinal study, the Asthma Coalition on Community, Environment and Social Stress (ACCESS), as a case study to exemplify both the opportunities and challenges of transdisciplinary research on urban asthma expression in the United States.

Determinants of the incidence of childhood asthma: a two-stage case-control study

Extensive literature exists on potential risk factors for childhood asthma. To the authors' knowledge, no investigators have yet attempted to disentangle the effects of those determinants within a single study setting. The authors aimed to evaluate the independent effects of 47 potential determinants (from the prenatal, perinatal, and childhood periods) of asthma development in children within the first 10 years of life. From a Canadian birth cohort of 26,265 children (1990-2002), a 2-stage case-control study was conducted. In the first stage, 20 controls per case were selected from 3 administrative databases. In the second stage, selected mothers were mailed questionnaires for assessment of additional determinants. Increased risks of childhood asthma were found for > or =1 previous diagnosis of bronchopulmonary disease and atopic dermatitis in the child, oxygen administration after birth, prescription of antibiotics within the first 6 months of life, male gender, asthma during pregnancy, use of antibiotics during pregnancy, maternal receipt of social aid, paternal asthma, and asthma in siblings. Protective effects included use of intranasal corticosteroids during pregnancy, having a wood-burning fireplace, having pets in the home prior to the index date, breastfeeding, and day-care attendance. This study allowed the authors to identify, within a single setting, the most influential determinants of childhood asthma among 47 predictors assessed for the prenatal, perinatal, and childhood periods.

Low income as a protective factor against asthma in children and adolescents treated via the Brazilian Unified Health System

OBJECTIVE

To analyze the role that low income plays in the development of asthma in children and adolescents.

METHODS

A case-control study using a questionnaire.

RESULTS

A total of 687 participants were studied at a tertiary hospital via the Brazilian Unified Health System. Ages ranged from 5 to 15 years, and 54.7% of the participants were male. Nearly half of the individuals (49.1%) lived in the metropolitan area of the city of Recife, and the remainder lived in the countryside. Most (98.1%) lived in concrete houses or apartments, with a mean of 5.7 rooms and 4.8 occupants per residence. Mean maternal level of education was 6.8 years of schooling. The median monthly per capita income was R$ 103.75 (Brazilian reals). The sample was stratified according to cut-off points related to the national minimum wage (R$350.00): <25% of minimum wage = very low income (39% of the sample); <50% of minimum wage = low income (37.3% of the sample); and > or =50% of minimum wage = satisfactory income (23.7% of the sample). There was no association between poverty and development of asthma.

CONCLUSIONS

Poverty is not protective against asthma in children and adolescents treated via the Brazilian Unified Health System, as we might suppose based on the hygiene hypothesis. However, cohort studies are needed in order to confirm these findings.

[The effects of season at time of birth on asthma and pneumonia in childhood and adulthood in a birth cohort in southern Brazil]

This study evaluated the effects of seasonal weather at time of birth and ambient temperature during the first six months of life on hospitalizations due to asthma and pneumonia in preschool children and on diagnosis of asthma in adulthood among individuals from the 1982 birth cohort in Pelotas, Rio Grande do Sul, Brazil. The cohort included 5,914 live births, of which 77% were followed up until adulthood (23-24 yr). The risk of hospitalization due to pneumonia and asthma among children born from April to June (autumn) was 1.31 (95%CI: 0.99-1.73) to 2.4 (95%CI: 1.11-4.99) times higher than that of children born from January to March (summer). For temperature in the first six months of life, risk of hospitalization was 1.64 (95%CI: 1.26-2.13) to 3.16 (95%CI: 1.63-6.12) times higher for children born in the coldest as compared to the hottest temperature tertile. The effects of seasonality decreased with age, and the association with asthma in adulthood was weak. Hospitalizations in poor children were more frequent, but the effects of seasonality on pneumonia were more evident among the wealthiest.

Prevalence of allergic symptoms among children with diabetes mellitus type 1 of different socioeconomic status

The aim of the study was to assess the possible associations between allergies and type 1 diabetes mellitus (DM1), stratified by social class. We studied 127 children with DM1 with a median age of 10.8 yr and 150 controls of comparable age and sex distribution. The parents completed questionnaires on their education and occupation and on their children's history of allergic symptoms, breast-feeding, viral infections, and measles-mumps-rubella (MMR) vaccination. Lower family's social class was more frequently encountered among the DM1 families than in the controls (OR = 0.56, 95% CI: 0.35-0.92). The occurrence of any allergic symptoms among children with DM1 (35.45%) was not significantly different from the controls (38.78%), neither in the total group (OR = 0.87, 95% CI: 0.52-1.45) nor in the stratified analysis by social class. Similar findings were observed regarding the different types of allergic symptoms. In the univariate analysis, breast-feeding, the experience of viral infections, and MMR vaccination were found to be protective of DM1 presentation in both upper and lower social classes. In the multiple logistic regression analysis, the experience of more than 2 infections/yr (OR = 0.12, 95% CI: 0.04-0.34), the origin from middle and upper social classes (OR = 0.42, 95% CI: 0.22-0.80) and breast-feeding (OR = 0.58, 95% CI: 0.31-1.07) were protective of DM1 occurrence. In children with DM1, the presence of allergic symptoms was not associated with the development of DM1. Among the environmental factors, the origin from middle or upper social classes, breast-feeding, the experience of viral infections, and MMR vaccination were found to have a protective effect on DM1 presentation.

Medicaid patient asthma-related acute care visits and their associations with ozone and particulates in Washington, DC, from 1994-2005

The primary objective of this ecologic and contextual study is to determine statistically significant short-term associations between air quality (daily ozone and particulate concentrations) and Medicaid patient general acute care daily visits for asthma exacerbations over 11 years for Washington, DC residents, and to identify regions and populations that may experience increased asthma exacerbations related to air quality. After removing long-term trends and day-of-week effects in the Medicaid data, Poisson regression was applied to daily time series data. Significant associations were found between asthma-related general acute care visits and ozone concentrations. Significant associations with both ozone and PM2.5 concentrations were observed for 5- to 12-year-olds. While poor air quality was closely associated with asthma exacerbations observed in acute care visits in areas where Medicaid enrollment was high, the strongest associations between asthma-related visits and air quality were not always for the areas with the highest Medicaid enrollment.

Household conditions, eczema symptoms and rhinitis symptoms: relationship with wheeze and severe wheeze in children living in the Polokwane area, South Africa

BACKGROUND

This is the fifth study that applied the International Study of Asthma and Allergies in Childhood (ISAAC) methodology in the Southern African Development Community (SADC region). However, it is the first ISAAC study that focused on 6- to 7-year-old children living in South Africa and that also investigated the association between potential risk factors and asthma symptoms. Objective To assess the 12-month prevalence of wheeze and severe wheeze along with their potential risk factors. Setting Within a 60-km radius from the Polokwane city centre, Limpopo Province.

METHODS

The survey was conducted during August 2004 and February 2005. Parents/guardians of 6- to 7-year-old children completed the questionnaires in English, Afrikaans or North-Sotho. However, the statistical analyses were restricted to the North-Sotho group (n = 2,437).

RESULTS

The 12-month prevalence rates of wheeze and severe wheeze were 11.2% and 5.7%, respectively. The 12-month prevalence rates of eczema symptoms and rhinoconjunctivitis symptoms were 8.0% and 7.3%, respectively. Living in a rural area significantly decreased the likelihood of wheeze by 31%. Exposure to environmental tobacco smoke at home and the presence of eczema symptoms and rhinoconjunctivitis symptoms increased the likelihood of wheeze by 77%, 104% and 226%, respectively. Only the presence of rhinoconjunctivitis symptoms increased the likelihood of severe wheeze by 107%.

CONCLUSION

Wheeze appears to be an emerging public health problem in the Polokwane area. Hopefully, detailed analytical intervention studies will further explicate these results in the near future.

Socioeconomic status and lung function

Poverty is a major social problem in the United States and throughout much of the world. Poverty and the broader term socioeconomic status (SES) are important determinants of overall health status and many pulmonary diseases. The purpose of this study was to review the medical literature from the past 20 years addressing the relationship between SES and lung function in both children and adults. There is a significant negative correlation between lung function (primarily FEV1 and FVC) and SES. This relationship exists even after adjusting for smoking status, occupational exposures, and race. The magnitude of the effect of low SES on lung function is variable, but FEV1 reductions of >300 mL in men and >200 mL in women have been reported. SES is an important determinant of lung function and an underrecognized contributor to pulmonary disease.

Household conditions, eczema symptoms and rhinitis symptoms: relationship with wheeze and severe wheeze in adolescents living in the Polokwane area, South Africa

OBJECTIVE

Determine the prevalence and risk factors of wheeze and severe wheeze in 13-to 14-year-old children.

METHODS

The study was conducted August 2004 to February 2005 in the Polokwane area, South Africa.

RESULTS

The 12-month prevalence rate was 18.9% for wheeze and 9.2% for severe wheeze (n = 3,926). The presence of other allergic symptoms and industrial activities appear to increase the likelihood of wheeze, even more so for severe wheeze. Socioeconomic-related factors appear to have a protective effect on wheeze.

CONCLUSIONS

Wheeze appears to be a substantial public health problem in the Polokwane area.