Health disparities in the United States: childhood asthma

Are Phthalate Exposure Related to Oxidative Stress in Children and Adolescents with Asthma? A Cumulative Risk Assessment Approach

Childhood asthma has become one of the most common chronic diseases in children and adolescents. However, few case–control studies investigating the relationship between phthalate exposure and asthma in children and adolescents have been conducted, especially in Asia. Therefore, we assessed the potential associations between phthalate exposure and asthma among children and adolescents in Taiwan. Because various demographic and environmental variables may influence the incidence and prognosis of asthma, we performed a case–control study with propensity score matching. Out of 615 Childhood Environment and Allergic Diseases Study participants, we conditionally matched 41 children with clinically diagnosed asthma with 111 controls. We then analyzed 11 phthalate metabolites by using liquid chromatography with tandem mass spectrometry. Compared with the control group, the median urinary phthalate levels for most phthalate metabolites in the case group were slightly increased, including monomethyl phthalate, mono-n-butyl phthalate, monobenzyl phthalate, monoethylhexyl phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, and mono-(2-carboxymethylhexyl) phthalate. Hence, our results suggest that phthalate exposure may be associated with the development of asthma. In addition, prenatal environmental factors, such as active or passive smoking during pregnancy, may increase the risk of asthma.

Mapping inequality: Childhood asthma and environmental injustice, a case study of St. Louis, Missouri

As a geographic continuum of poverty and affluence has emerged, so too has a geographic continuum of good and poor health. Asthma is currently one of the most prevalent chronic childhood diseases. Over the past three decades, the greatest increases in asthma rates have been in urban areas and have disproportionately affected youth in poverty and those in racial and ethnic minority groups. Neighborhoods serve as a mechanism fostering environmental injustice and perpetuating these disparities in health outcomes and life opportunity for our most vulnerable populations. Using Geographic Information Systems (GIS) methods in a case study of St. Louis Missouri, this study examines local environmental risk by identifying 'hotspots,' or statistically significant spatial clustering of high or low levels of childhood asthma, and associations with neighborhood characteristics, socio-demographic characteristics, and access to healthcare resources within these hotspots. Results revealed statistically significant clustering of high asthma rates in areas with more non-White and poor residents, higher rates of public housing, deteriorating housing, and violent crime. High asthma hotspots were also located in areas with limited physical access to healthcare resources, such as physicians and medication, and lower school attendance rates. Residents of these high asthma hotspots experience greater environmental risk, and significant disparities in health and education outcomes, physical and financial healthcare resources, and overall well-being. This study demonstrates these place-based inequalities and presents clear evidence of environmental injustice, supporting the need for investments and interventions to improve the environments, health, and economic resources of our most vulnerable youth.

Beliefs Regarding Asthma Management Relating to Asthma Action Plans (AAPs) of African American Caregivers Residing in Newark, New Jersey Public Housing Communities

PURPOSE

The purpose of this study was to explore the beliefs regarding asthma management and Asthma Action Plans (AAPs) of African American caregivers residing in three New Jersey public housing communities in Newark, New Jersey.

DESIGN

A qualitative methods design was accomplished using semi-structured interviews with a purposive sample of nine African American caregivers of children with asthma. Information was coded using N'VIVO™; the textual analysis combined codes into categories, which were then assembled into themes.

RESULTS

Self-determination was found to be a fundamental goal of asthma management; however, three themes emerged as barriers and facilitators to this goal: challenges in the urban environment, preference of familial methods, and access to medical care.

CONCLUSIONS

Findings from this study regarding minority caregivers' beliefs regarding difficulty navigating the health care system coupled with insurance instability, leading to use of Emergency Departments, are consistent with past research. Although caregivers expressed belief in use of prescribed medications as indicated on AAPs, familial methods, found to provide a sense of control over asthma, were preferred.

Asthma-related deaths

Despite major advances in the treatment of asthma and the development of several asthma guidelines, people still die of asthma currently. According to WHO estimates, approximately 250,000 people die prematurely each year from asthma. Trends of asthma mortality rates vary very widely across countries, age and ethnic groups. Several risk factors have been associated with asthma mortality, including a history of near-fatal asthma requiring intubation and mechanical ventilation, hospitalization or emergency care visit for asthma in the past year, currently using or having recently stopped using oral corticosteroids (a marker of event severity), not currently using inhaled corticosteroids, a history of psychiatric disease or psychosocial problems, poor adherence with asthma medications and/or poor adherence with (or lack of) a written asthma action plan, food allergy in a patient with asthma. Preventable factors have been identified in the majority of asthma deaths. Inadequate education of patients on recognising risk and the appropriate action needed when asthma control is poor, deficiencies in the accuracy and timing of asthma diagnosis, inadequate classification of severity and treatment, seem to play a part in the majority of asthma deaths. Improvements in management, epitomized by the use of guided self-management systems of care may be the key goals in reducing asthma mortality worldwide.

Ethnic variations in asthma hospital admission, readmission and death: a retrospective, national cohort study of 4.62 million people in Scotland

BACKGROUND

Our previous meta-analysis found that South Asians and Blacks in the UK were at a substantially increased risk of hospital admission from asthma. These estimates were, however, derived from pooling data from a limited number of now dated studies, confined to only three very broad ethnic groups (i.e. Whites, South Asians and Blacks) and failed to take account of possible sex-related differences in outcomes within these ethnic groups. We undertook the first study investigating ethnic variations in asthma outcomes across an entire population.

METHODS

This retrospective 9-year cohort study linked Scotland's hospitalisation/death records on asthma to the 2001 census (providing ethnic group). We calculated age, country of birth and Scottish Index of Multiple Deprivation adjusted incident rate ratios (IRRs) for hospitalisation or death by sex for the period May 2001-2010. We calculated hazard ratios (HRs) for asthma readmission and subsequent asthma death.

RESULTS

We were able to link data on 4.62 million people (91.8% of the Scottish population), yielding over 38 million patient-years of data, 1,845 asthma deaths, 113,795 first asthma admissions, and 107,710 readmissions (40,075 of which were for asthma). There were substantial ethnic variations in the rate of hospitalisation/death in both males and females. When compared to the reference Scottish White population, the highest age-adjusted rates were in Pakistani males (IRR = 1.59; 95% CI, 1.30-1.94) and females (IRR = 1.50; 95% CI, 1.06-2.11) and Indian males (IRR = 1.34; 95% CI, 1.16-1.54), and the lowest were seen in Chinese males (IRR = 0.62; 95% CI, 0.41-0.94) and females (IRR = 0.49; 95% CI, 0.39-0.61).

CONCLUSION

There are very substantial ethnic variations in hospital admission/deaths from asthma in Scotland, with Pakistanis having the worst and Chinese having the best outcomes. Cultural factors, including self-management and health seeking behaviours, and variations in the quality of primary care provision are the most likely explanations for these differences and these now need to be formally investigated.

Sex-Based Differences in Asthma among Preschool and School-Aged Children in Korea

The purpose of this study was to explore risk factors related to asthma prevalence among preschool and school-aged children using a representative national dataset from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted from 2009–2011. We evaluated the demographic information, health status, household environment, socioeconomic status, and parents’ health status of 3,542 children aged 4–12 years. A sex-stratified multivariate logistic regression was used to obtain adjusted prevalence odds ratios (ORs) and 95% confidence intervals after accounting for primary sample units, stratification, and sample weights. The sex-specific asthma prevalence in the 4- to 12-year-old children was 7.39% in boys and 6.27% in girls. Boys and girls with comorbid atopic dermatitis were more likely to have asthma than those without atopic dermatitis (boys: OR = 2.20, p = 0.0071; girls: OR = 2.33, p = 0.0031). Boys and girls with ≥1 asthmatic parent were more likely to have asthma than those without asthmatic parents (boys: OR = 3.90, p = 0.0006; girls: OR = 3.65, p = 0.0138). As girls got older, the prevalence of asthma decreased (OR = 0.90, p = 0.0408). Girls residing in rural areas were 60% less likely to have asthma than those residing in urban areas (p = 0.0309). Boys with ≥5 family members were more likely to have asthma than those with ≤3 family members (OR = 2.45, p = 0.0323). The factors related to asthma prevalence may differ depending on sex in preschool and school-aged children. By understanding the characteristics of sex-based differences in asthma, individualized asthma management plans may be established clinically.

Family socioeconomic status, household tobacco smoke, and asthma attack among children below 12 years of age: gender differences

Studies have demonstrated the negative impact of environmental tobacco smoke (ETS) or parental cigarette smoking on pediatric asthma. Little is known, however, regarding whether there is a gender difference in the effect of household ETS on pediatric asthma. Using a nationwide survey in Taiwan, we examined the relationship between asthma prevalence in the past year and household ETS among children below 12 years of age (N = 3761). We used multivariate regression models to assess odds ratios (ORs) and 95% confidence intervals (CIs) for the association of household ETS and asthma attacks by gender. In about 3% of the sample, parents reported that their children had an asthma attack in the past year, confirmed by physicians. Multivariate logistic regression revealed that household ETS predicted asthma attacks for girls (OR = 3.11, 95%CI = 1.24-7.76) but not for boys. Father's education was significantly associated with asthma attack for both girls (OR = 1.24, 95%CI = 1.04-1.47) and boys (OR = 1.15, 95%CI = 1.05-1.26). Girls with lower family income were more likely to have had an asthma attack in the last year (OR = .48, 95%CI = .27-.87). The impact of household ETS and family socioeconomic status on asthma attacks differs by gender among children below 12 years.

Changes in long-acting β-agonist utilization after the FDA's 2010 drug safety communication

PURPOSE

In February 2010, the US Food and Drug Administration (FDA) issued new recommendations for the safe use of long-acting β-agonists (LABAs) in patients with asthma. The objective of this study was to determine the impact of the FDA's 2010 safety advisory on LABA utilization.

METHODS

Using administrative data from the Oregon Medicaid program, we performed an interrupted time series regression to evaluate changes in the trend in new LABA prescriptions before and after the FDA's 2010 advisory. Trends in incident fills were examined among those with and without an asthma diagnosis code and previous respiratory controller medication use; trends were also assessed according to patient age.

FINDINGS

The average age of the 8646 study patients was 37 years, 53% had a diagnosis of asthma, 21% had no respiratory diagnosis, and 32% had not used a respiratory controller medication in the recent past. The trend in new LABA prescriptions declined by 0.09 new start per 10,000 patients per month (95% CI, -0.19 to -0.01) after the FDA's advisory. Among those with a diagnosis of asthma, there was an immediate drop of 0.48 (95% CI, -0.93 to -0.03) and a 0.10 (95% CI, -0.13 to -0.06) decline in the monthly rate of new starts per 10,000 patients. Immediately after the FDA's advisory, we observed a statistically significant 4.7% increase (95% CI, 0.8 to 8.7) in the proportion of new LABA starts with history of previous respiratory controller medication use. Utilization of LABAs did not change in those without a diagnosis of asthma.

IMPLICATIONS

The FDA's 2010 advisory was associated with modest reductions in LABA utilization overall and in ways highlighted in their recommendations.

Asthma coalition effects on vulnerable sub groups of children: the most frequent users of health care and the youngest

OBJECTIVE

To examine the impact of Allies Against Asthma, community-based coalitions working to improve asthma outcomes, on vulnerable children: those with the most urgent health care use and those of youngest age.

METHODS

Allies zip codes were matched with comparison communities on demographic factors. Five years of Medicaid data (n = 26,836) for significant health care events: hospitalizations, ED and urgent care facility visits, were analyzed. Longitudinal analyses using generalized estimating equations and proportional hazards models compared Allies and comparison group children.

RESULTS

In the two start-up years of Allies, odds of having a significant event were greater for Allies children than for comparison children (p < 0.05). During the third and fourth years when Allies activities were fully implemented, for frequent health care users at baseline, odds of an asthma event were the same for both Allies and comparison children, yet in the less frequent users, odds of an event were lower in Allies children (p < 0.0001). In the initial year of Allies efforts, among the youngest, the Allies children had greater odds than comparison children of an event (p < 0.01), but by the fourth year the Allies group had lower odds (p = 0.02) of an event. Hazard ratios over all years of the study for the youngest Allies children and most frequent baseline users of urgent care were lower than for comparison children (p = 0.01 and p = 0.0004).

CONCLUSION

Mobilizing a coalition of diverse stakeholders focused on policy and system change generated community-wide reductions over the long-term in health care use for vulnerable children.

Asthma, tobacco smoke and the indoor environment: a qualitative study of sheltered homeless families

OBJECTIVE

Asthma is common in homeless children with an incidence of 28-40%. There are few published studies investigating asthma in homeless children. This study examines the perspectives of both caregivers and shelter staff regarding challenges and opportunities of caring for children with asthma.

METHODS

A focus group of sheltered parents (n = 10) with children who have asthma was conducted to identify barriers to optimal asthma management. Key informant interviews (n = 6) were conducted with shelter staff to discuss the shelter systems and policies to address childhood asthma. Data were audio-recorded and transcribed. A representative analysis team performed qualitative theme analysis.

RESULTS

Key themes across 5 domains were identified: asthma education, access to asthma medication and equipment, asthma action plans, structural barriers to asthma management and environmental triggers. Parents identified multiple asthma triggers present in the shelter environment but cited lack of control as a barrier to remediation. Shelter staff desired elimination of asthma triggers but refer to the lack of resources as the primary barrier. Shelter staff favored a smoking ban on shelter property but named challenges to policy implementation. Both parents and staff identified asthma education and increased access to medications would be helpful.

CONCLUSIONS

Policies to reduce environmental exposures, such as a smoking ban, to asthma triggers has the potential to improve the health of sheltered children with asthma.

Health service deficits and school-aged children with asthma: a population-based study using data from the 2007-2008 National Survey of Child Health

BACKGROUND

Asthma is one of the most common and costly illnesses of childhood. This study addresses health services deficits experienced by school-aged children with asthma.

METHODS

Analyzing data from the 2007-2008 National Survey of Child Health, this cross-sectional study used household income, race/ethnicity, and geographic residency as the primary independent variables and health service deficits as the dependent variable.

RESULTS

Multivariate analysis yielded that other/multiracial (odds ratio [OR], 1.234; 95% confidence interval [CI], 1.226-1.242) and Hispanic (OR, 2.207; 95% CI, 1.226-1.242) school-aged children with asthma had greater odds of having health services deficits as did both urban (OR, 1.106; 95% CI, 1.099-1.113) and rural (OR, 1.133; 95% CI, 1.124-1.142) school-aged children with asthma. Children with either moderate (OR, 1.195; 95% CI, 1.184-1.207) or mild (OR, 1.445; 95% CI, 1.431-1.459) asthma had greater odds of having a health services deficit than those with severe asthma. Low-income school-aged children with asthma had greater odds of having a health services deficit than high-income children (OR, 1.031; 95% CI, 1.026-1.036). At lesser odds of having a health service deficit were those who were African American, of middle-range income, male, or who were school-aged children with asthma in good to excellent health.

CONCLUSION

Both African American and other/multiracial school-aged children were at greater risk of having asthma than either Caucasian or Hispanic children. Three vulnerable subgroups of school-aged children with asthma-rural, Hispanic, and those of low income were the most likely to have health service deficits.

Socioeconomic determinants associated with willingness to participate in medical research among a diverse population

INTRODUCTION

Although it is federally-mandated that racial/ethnic minorities be included in research studies, recruiting diverse populations remains a challenge. This is particularly difficult when research involves children. The purpose of this study was to assess attitudes and beliefs toward medical research among a racially and socioeconomically diverse population of parents of school children.

METHODS

A cross-sectional parent-report survey was conducted in New York City public elementary schools using stratified random selection to obtain a diverse population. Fear of medical research and likelihood to participate in medical research were assessed using a validated questionnaire. Differences in fear/likelihood to participate in research across race/ethnicity and socioeconomic characteristics were evaluated.

RESULTS

In general, parents were afraid of their child "being treated as a guinea pig", but were willing to allow their child to participate in research if asked by their own doctor. Factors associated with a lower score on fear toward research were; primary language other than English (OR=0.59), access to an interpreter (OR=0.73) and access to medical service within a day (OR=0.51). Latinos had the highest fear score (OR=1.87) compared to Whites. Asians were the ethnic group most likely to participate in research (OR=1.71). Low education level (OR=2.18) and public health insurance (OR=1.37) were associated with a higher score for likelihood of allowing one's child to participate in medical research.

CONCLUSION

Minority parents reported more fear of allowing their children to participate in medical research, but were as likely to consent their children's participation, especially if asked by their own physician.

Healthcare inequalities in paediatric respiratory diseases

Identifying that health inequalities exist is not enough; nor does the knowledge that a patient has a high-risk genotype or comes from a higher risk socioeconomic background does not, by itself, help the patient. To thoroughly examine the origins of health disparities, a broad view of environmental and molecular influences must be included. As these factors are identified, it is important to focus on interventions that can change outcomes for patients. Tools for education, community involvement, literacy, and environmental safety need to be developed, tested and disseminated. The basic science of health disparities must move forward in a coordinated fashion by structuring research that is an integrated effort between basic sciences, clinical medicine and include all traditionally underserved communities. Only through these collaborations can we hope to eliminate health inequalities in the future.

Association between biomarker-quantified antioxidant status during pregnancy and infancy and allergic disease during early childhood: a systematic review

Recent findings suggest a significant association between the antioxidant status of pregnant women and of their children during the first years of life and the development of allergic disease during childhood. The aim of this review was to identify all studies that estimated the effect of intake of antioxidants in pregnant women and their children on the development of allergic disease during early childhood. A systematic review was conducted of epidemiological studies featuring original peer-reviewed data on the association between dietary antioxidant status and allergic disease during childhood. A systematic search was performed following the Meta-analysis of Observational Studies in Epidemiology Guidelines. A comprehensive search of the literature yielded 225 studies, 18 of which were selected for the extraction of results and were related to antioxidant status and allergic disease. The systematic review included five prospective cohort studies, four cross-sectional studies, and nine case-control studies. Eight studies reported an important association between antioxidant status and asthma onset during childhood. Similarly, wheezing and eczema were studied as an outcome in six and in five studies, respectively. Recent observational studies suggest that a higher intake of antioxidant vitamins, zinc, and selenium during pregnancy and childhood reduces the likelihood of childhood asthma, wheezing, and eczema.

A population-based study of health service deficits for US adults with asthma

OBJECTIVE

Asthma prevalence in the United States is higher than it is in many other countries and its impact in terms of healthcare expenditures and morbidity and mortality is staggering. In the United States, many groups bear a disproportionate burden of asthma. Understanding the epidemiology of adult asthma and deficits in health care can identify opportunities for improving care and effectively managing resources.

METHODS

The computed dependent variable, health service deficits, entails a lack of health insurance, not having a healthcare provider, deferring medical care because of cost, and having had no routine medical exam. Bivariate and multivariate analyses were performed on 2005 Behavioral Risk Factor Surveillance Survey data to examine the relationship between health service deficits experienced by adults with asthma and socioeconomic status (SES), race and ethnicity, and geographic locale. The variable was also calculated for each US state.

RESULTS

Hispanic (OR = 1.594, 95% CI = 1.588-1.599) and Other/Multiracial (OR = 1.447, 95% CI = 1.441-1.452) adults with current asthma had greater odds of having a health service deficit. Rural adults with current asthma had greater odds of having a health service deficit (OR = 1.086, 95% CI = 1.083-1.089) when compared with non-rural adult residents. Low-SES (OR = 1.976, 95% CI = 1.971-1.982) and middle-SES (OR = 1.596, 95% CI = 1.592-1.600) adults with current asthma had greater odds of having a health service deficit. The percentage of current asthma adults experiencing at least one health service deficit by state ranged from a low of 28.5% (Delaware) to a high of 58.8% (Wyoming).

CONCLUSION

There are clear patterns of disparity associated with health services and asthma that can help target interventions.

The Breathmobile program: a good investment for underserved children with asthma

BACKGROUND

The Breathmobile, a specialty-based mobile asthma clinic, provides free care to underserved children. The cost of symptom-free day (SFD) improvement in this population has not been previously reported.

OBJECTIVE

To examine the clinical impact and cost-effectiveness of the Baltimore Breathmobile.

METHODS

Existing computerized data were analyzed for Breathmobile patient visits between 2002 and 2007. All SFDs were calculated, and direct medical cost savings attributable to decreased emergency department visits and hospitalizations (after program utilization vs the previous year) were compared with annual operating costs. Incremental cost-effectiveness ratios were determined by calculating the incremental costs of Breathmobile care per additional SFD gained per child per year.

RESULTS

The analysis included 255 patients enrolled in the program for at least 1 year. Most participants were black (93.3%), and 54.9% were male. At baseline, patients reported a mean (SD) of 199 (118) SFDs in the year before enrollment. After 1 year in the program, patients had a mean (SD) improvement of 44 (9) SFDs. The program resulted in overall cost savings of $79.43 per SFD gained, with greater cost savings for children aged 5 to 11 years (-$116.84 per SFD gained) and those with intermittent asthma (-$126.71 per SFD gained).

CONCLUSIONS

The Baltimore Breathmobile program has demonstrated significant improvement in SFDs, with direct medical cost savings of the program outweighing the operational costs. These data support the need to continue to sustain and expand Breathmobile programs for children at high risk for asthma exacerbations and to conduct a randomized clinical trial to estimate the cost-effectiveness of the Breathmobile.

Using information technology to reduce asthma disparities in underserved populations: a pilot study

BACKGROUND

Low health literacy has been identified as an independent predictor of poor asthma control. The Institute of Medicine considers the role of information technology (IT) as critical in providing "safe, effective, patient centered, timely, efficient, and equitable" care with the potential to reduce health disparities in underserved populations. The aim of this study was to design and evaluate an interactive computer-based questionnaire to assess asthma symptoms in children of parents with limited health literacy and/or limited English proficiency.

METHODS

Volunteer caregivers attending a mobile asthma clinic were randomly assigned to complete the electronic or the paper-and-pencil version of an asthma screening questionnaire (ASQ) in their language of choice (English or Spanish). In the electronic version, a tablet computer was used to present the ASQ questions as video clips and to collect information through the touchscreen. Participants also completed a demographic questionnaire, a brief health literacy questionnaire, and a system usability and satisfaction questionnaire. Reliability of the paper and electronic self-assessments was evaluated by comparing each participant's answers to information they provided during a nurse-guided structured interview (gold standard).

RESULTS

A total of 48 parents participated in the study, 26 completed the electronic ASQ and 21 the paper-and-pencil form. Thirty-five percent of the children had well-controlled asthma (n = 17). Most participants were Spanish speaking (67%) Hispanic (n = 44) mothers (n = 43) with a median age of 32 years. More than half had ≤8 years of education (n = 25) and earned <$20,000 per year (n = 27). The median health literacy score was 32 (range 0-36). The correlation between health literacy scores and years of education was significant (ρ = .47, p < .01). Concordance between the electronic ASQ and the nurse interview was significantly higher than concordance between the paper ASQ and the nurse interview (68% versus 54%; p < .01). All parents who completed the electronic questionnaire reported being satisfied; 96% felt comfortable using it, and found it simple to use.

CONCLUSIONS

By facilitating the assessment of asthma symptoms at manageable cost, interactive information technology tools may help reduce barriers to access due to inadequate levels of English proficiency and health literacy.

Health disparities: a primer for public health social workers

In 2001, the U.S. Department of Health and Human Services published Healthy People 2010, which identified objectives to guide health promotion and to eliminate health disparities. Since 2001, much research has been published documenting racial and ethnic disparities in healthcare. Although progress has been made in eliminating the disparities, ongoing work by public health social workers, researchers, and policy analysts is needed. This paper focuses on racial and ethnic health disparities, why they exist, where they can be found, and some of the key health/medical conditions identified by the U.S. Department of Health and Human Services to receive attention. Finally, there is a discussion of what policy, professional and community education, and research can to do to eliminate racial and ethnic disparities in healthcare.

Phthalate exposure and asthma in children

During the last decades more than 100 000 new chemicals have been introduced to the environment. Many of these new chemicals and many common consumer products that include these have been shown to be toxic in animal studies and an increasing body of evidence suggests that they are also impacting human health. Among the suspect chemicals, the endocrine disrupting chemicals (EDCs) are of particular concern. One such chemical group is the phthalates, used in soft poly vinyl chloride (PVC) material and in a huge number of consumer products. During the same period of time that the prevalence of these modern chemicals has increased, there has been a remarkable increase in several chronic illnesses, including asthma and allergy in children. In this article we outline the scientific knowledge on phthalate exposure for asthma and airway diseases in children by examining epidemiological and experimental peer review data for potential explanatory mechanisms. Epidemiological data point to a possible correlation between phthalate exposure and asthma and airway diseases in children. Experimental studies present support for an adjuvant effect on basic mechanisms in allergic sensitization by several phthalates. Despite variations in the experimental design and reported result in the individual studies, a majority of published reports have identified adjuvant effects on Th2 differentiation, production of Th2 cytokines and enhanced levels of Th2 promoted immunoglobulins (mainly IgG1 but also IgE) in mice. A limited amount of data do also suggest phthalate-induced enhancement of mast cell degranulation and eosinophilic infiltration which are important parts in the early inflammation phase. Thus, some of the early key mechanisms in the pathology of allergic asthma could possibly be targeted by phthalate exposure. But the important questions of clinical relevance of real life exposure and identification of molecular targets that can explain interactions largely remain to be answered.

Asthma patients' perception of their ability to influence disease control and management

BACKGROUND

Patients' perception of their ability to influence their asthma symptoms has not been sufficiently addressed.

OBJECTIVE

To study the relationship between patients' perceived ability to self-care, as approached by internal locus of control (LOC) orientation, and concomitant level of asthma control.

METHODS

A cross-sectional study was conducted from May 19, 2004, through July 7, 2005. Asthma patients receiving inhaled corticosteroids and supervised in primary care were identified. Asthma control was measured with the Asthma Control Test. Patients reported their LOC orientation on a 100-mm visual analog scale (0%, "I have absolutely no influence on asthma change," to 100%, "this change only depends on me"). Asthma therapy was obtained from a prescription database. The risk of an internal LOC of less than 50% was studied.

RESULTS

Among the 163 patients with documented LOC (mean age, 52 years; 58% female), 72 (44.2%) had an internal LOC of less than 50%. Asthma control was inadequate for 65 of the 157 patients with available data on the global score of the Asthma Control Test (41.4%). Patients with inadequately controlled asthma had a higher risk of a LOC of less than 50% (odds ratio, 2.68; 95% confidence interval, 1.23-5.81). A 3-fold increased risk also appeared for patients older than 65 years compared with those younger than 45 years. Conversely, no association was identified with sex, asthma severity markers, or therapy.

CONCLUSIONS

Asthma control was related to internal LOC orientation (ie, perceived ability to self-care). Improved self-care efficiency is a target for adequate disease management.

Asthma symptoms and airway narrowing in children growing up in an urban versus rural environment

The development of asthma and allergy appears to be the result of gene-environment interaction. Potential environmental risk factors such as outdoor and indoor air pollution, infections, allergen exposure, diet, and lifestyle patterns may trigger respiratory symptoms and compromise lung function in children. Specific features of urban and rural lifestyle may constitute distinct risk factors but may also coexist within certain socioeconomic levels. Children of rural environments are at lower risk for asthma and aeroallergen sensitization. The protective effect has been associated with close contact with large animals, but the genetic factor also plays a contributory role. Children with prolonged exposure to urban environment are at increased risk of reduced lung function and those that reside in polluted areas exhibit slower lung growth. It is possible that polluted urban environment per se facilitates subclinical small airway disease. Evidence to date supports a strong relation between residential area as a potential risk factor for childhood asthma symptoms and airway obstruction and a western type of socioeconomic development.

Barriers to care questionnaire: reliability, validity, and responsiveness to change among parents of children with asthma

BACKGROUND

Although it is well known which groups of children are more vulnerable to poor health care access, quality, and outcomes, less is known about how and why this occurs. Barriers to care-sociobehavioral processes that interfere with successful interaction with the health care system--may be a link between vulnerability and access, experiences, and outcomes.

OBJECTIVE

The aim of this study was to examine the reliability, validity, and responsiveness to change of the Barriers to Care Questionnaire (BCQ) in a sample of children with persistent asthma recruited from federally qualified health centers.

METHOD

Children (N = 252; aged 2-14 years) with persistent asthma and their parents (93.7% mother, 83.3% Hispanic, 76.9% Spanish speaking; 72.6% less than a high school diploma), enrolled in a clinical trial, and completed the BCQ, questions relating to access to care, the Parent's Perceptions of Primary Care Measure, and the Pediatric Quality of Life Inventory 4.0 (PedsQL) at baseline and 3 months.

RESULTS

The BCQ demonstrated internal consistency reliability. Supporting construct validity, barriers to care were worse for children without health insurance or an identified provider and who had problems with care or foregone care. Higher barriers correlated with poorer primary care and lower patient health-related quality of life. The BCQ was responsive to change, showing within- and between-subject differences for subjects with improved realized access from baseline to 3 months.

CONCLUSION

The BCQ is a reliable, valid, and responsive measure of barriers to care for vulnerable children with asthma. Barriers to care were associated with poorer access, lower primary care quality, and worse health-related quality of life.

Early-life environment, developmental immunotoxicology, and the risk of pediatric allergic disease including asthma

Incidence of childhood allergic disease including asthma (AD-A) has risen since the mid-20th century with much of the increase linked to changes in environment affecting the immune system. Childhood allergy is an early life disease where predisposing environmental exposures, sensitization, and onset of symptoms all occur before adulthood. Predisposition toward allergic disease (AD) is among the constellation of adverse outcomes following developmental immunotoxicity (DIT; problematic exposure of the developing immune system to xenobiotics and physical environmental factors). Because novel immune maturation events occur in early life, and the pregnancy state itself imposes certain restrictions on immune functional development, the period from mid-gestation until 2 years after birth is one of particular concern relative to DIT and AD-A. Several prenatal-perinatal risk factors have been identified as contributing to a DIT-mediated immune dysfunction and increased risk of AD. These include maternal smoking, environmental tobacco smoke, diesel exhaust and traffic-related particles, heavy metals, antibiotics, environmental estrogens and other endocrine disruptors, and alcohol. Diet and microbial exposure also significantly influence immune maturation and risk of allergy. This review considers (1) the critical developmental windows of vulnerability for the immune system that appear to be targets for risk of AD, (2) a model in which the immune system of the DIT-affected infant exhibits immune dysfunction skewed toward AD, and (3) the lack of allergy-relevant safety testing of drugs and chemicals that could identify DIT hazards and minimize problematic exposure of pregnant women and children.