Understanding disparities in asthma outcomes among African Americans

Real-World Assessment of Asthma Control and Severity in Children, Adolescents, and Adults with Asthma: Relationships to Care Settings and Comorbidities

BACKGROUND

Little is known about how patient-level factors and care settings relate to asthma outcomes in real-world settings.

OBJECTIVE

We therefore examined the rates and relative contributions of comorbidities and care settings in terms of asthma severity and control among pediatric and adolescent/adult patients in a large national sample.

METHODS

We examined deidentified patient data from 28,508 unique encounters documented in the Asthma Specialist Tool to Help Manage Asthma and Improve Quality database, obtaining patient-level factors (demographics, asthma characteristics, comorbidities), care setting (primary care physician [PCP] vs specialist physician [allergist or pulmonologist]), and guideline-defined levels of asthma control/severity. Rates of comorbidities were identified by asthma severity and control and by care setting. We calculated odds ratios for asthma control and severity based on each comorbidity.

RESULTS

Baseline demographic data indicated that patients seen by specialists versus PCPs were older, and had more severe and poorly controlled asthma (P < .05). Patients cared for by specialists also had more comorbid conditions, including gastroesophageal reflux disease (GERD; P < .01), rhinosinusitis (P < .01), and obstructive sleep apnea (adolescents/adults only: P < .01). GERD, smoke exposure, depression (adolescents/adults), rhinosinusitis (children), and African American race were associated with uncontrolled asthma. Smoke exposure (children), rhinosinusitis, and African American race were associated with severe disease.

CONCLUSIONS

We identified several demographics and comorbidities that are independently associated with the specialist care setting, persistent asthma, and poor asthma control. Awareness of these relationships may be helpful for clinicians caring for patients with asthma.

Asthma and Corticosteroid Responses in Childhood and Adult Asthma

Corticosteroids are the most effective treatment for asthma; inhaled corticosteroids (ICSs) are the first-line treatment for children and adults with persistent symptoms. ICSs are associated with significant improvements in lung function. The anti-inflammatory effects of corticosteroids are mediated by both genomic and nongenomic factors. Variation in the response to corticosteroids has been observed. Patient characteristics, biomarkers, and genetic features may be used to predict response to ICSs. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

The influence of community violence and protective factors on asthma morbidity and healthcare utilization in high-risk children

We examined the longitudinal effects of community risk and protective factors on asthma morbidity and healthcare utilization. Three hundred urban caregivers of children with poorly controlled asthma were enrolled in a randomized controlled trial testing the effectiveness of a behavioral/educational intervention and completed measures of exposure to community violence (ECV), social cohesion (SC), informal social control (ISC), child asthma control, child asthma symptom days/nights, and healthcare utilization. Latent growth curve modeling examined the direct and interaction effects of ECV, SC, and ISC on the asthma outcomes over 12 months. Caregivers were primarily the biological mother (92 %), single (70 %), and poor (50 % earned less than $10,000). Children were African American (96 %) and young (mean age = 5.5 years, SD = 2.2). ECV at baseline was high, with 24.7 % of caregivers reporting more than two exposures to violence in the previous 6 months (M = 1.45, SD = 1.61). Caregiver ECV-predicted asthma-related healthcare utilization at baseline (b = 0.19, SE = 0.07, p = 0.003) and 2 months (b = 0.12, s.e. = 0.05, p = 0.04). ISC and SC moderated the effect of ECV on healthcare utilization. Our findings suggest that multifaceted interventions that include strategies to curb violence and foster feelings of cohesion among low-income urban residents may be needed to reduce asthma-related emergency services.

Self-management of multiple chronic conditions among African American women with asthma: a qualitative study

OBJECTIVE

African American women are disproportionately burdened by asthma morbidity and mortality and may be more likely than asthma patients in general to have comorbid health conditions. This study sought to identify the self-management challenges faced by African American women with asthma and comorbidities, how they prioritize their conditions and behaviors perceived as beneficial across conditions.

METHODS

In-depth interviews were conducted with 25 African-American women (mean age 52 years) with persistent asthma and at least one of the following: diabetes, heart disease or arthritis. Information was elicited on women's experiences managing asthma and concurrent health conditions. The constant-comparison analytic method was used to develop and apply a coding scheme to interview transcripts. Key themes and subthemes were identified.

RESULTS

Participants reported an average of 5.7 comorbidities. Fewer than half of the sample considered asthma their main health problem; these perceptions were influenced by beliefs about the relative controllability, predictability and severity of their health conditions. Participants reported ways in which comorbidities affected asthma management, including that asthma sometimes took a "backseat" to conditions considered more troublesome or worrisome. Mood problems, sometimes attributed to pain or functional limitations resulting from comorbidities, reduced motivation for self-management. Women described how asthma affected comorbidity management; e.g. by impeding recommended exercise. Some self-management recommendations, such as physical activity and weight control, were seen as beneficial across conditions.

CONCLUSIONS

Multiple chronic conditions that include asthma may interact to complicate self-management of each condition. Additional clinical attention and self-management support may help to reduce multimorbidity-related challenges.

Racial/ethnic disparities in the prevalence of selected chronic diseases among US Air Force members, 2008

INTRODUCTION

Few studies have evaluated possible racial/ethnic disparities in chronic disease prevalence among US Air Force active-duty members. Because members have equal access to free health care and preventive screening, the presence of health disparities in this population could offer new insight into the source of these disparities. Our objective was to identify whether the prevalence of 4 common chronic diseases differed by race/ethnicity in this population.

METHODS

We compiled de-identified clinical and administrative data for Air Force members aged 21 or older who had been on active duty for at least 12 months as of October 2008 (N = 284,850). Multivariate logistic regression models were used to determine the prevalence of hypertension, dyslipidemia, type 2 diabetes, and asthma by race/ethnicity, controlling for rank and sex.

RESULTS

Hypertension was the most prevalent chronic condition (5.3%), followed by dyslipidemia (4.6%), asthma (0.9%), and diabetes (0.3%). Significant differences were noted by race/ethnicity for all conditions. Compared with non-Hispanic whites, the prevalence of all chronic diseases was higher for non-Hispanic blacks; disparities for adults of other minority race/ethnicity categories were evident but less consistent.

CONCLUSION

The existence of racial/ethnic disparities among active-duty Air Force members, despite equal access to free health care, indicates that premilitary health risks continue after enlistment. Racial and ethnic disparities in the prevalence of these chronic diseases suggest the need to ensure preventive health care practices and community outreach efforts are effective for racial/ethnic minorities, particularly non-Hispanic blacks.

Impact of race on asthma treatment failures in the asthma clinical research network

RATIONALE

Recent studies suggest that people with asthma of different racial backgrounds may respond differently to various therapies.

OBJECTIVES

To use data from well-characterized participants in prior Asthma Clinical Research Network (ACRN) trials to determine whether racial differences affected asthma treatment failures.

METHODS

We analyzed baseline phenotypes and treatment failure rates (worsening asthma resulting in systemic corticosteroid use, hospitalization, emergency department visit, prolonged decrease in peak expiratory flow, increase in albuterol use, or safety concerns) in subjects participating in 10 ACRN trials (1993-2003). Self-declared race was reported in each trial and treatment failure rates were stratified by race.

MEASUREMENTS AND MAIN RESULTS

A total of 1,200 unique subjects (whites = 795 [66%]; African Americans = 233 [19%]; others = 172 [14%]; mean age = 32) were included in the analyses. At baseline, African Americans had fewer asthma symptoms (P < 0.001) and less average daily rescue inhaler use (P = 0.007) than whites. There were no differences in baseline FEV(1) (% predicted); asthma quality of life; bronchial hyperreactivity; or exhaled nitric oxide concentrations. A total of 147 treatment failures were observed; a significantly higher proportion of African Americans (19.7%; n = 46) experienced a treatment failure compared with whites (12.7%; n = 101) (odds ratio = 1.7; 95% confidence interval, 1.2-2.5; P = 0.007). When stratified by treatment, African Americans receiving long-acting β-agonists were twice as likely as whites to experience a treatment failure (odds ratio = 2.1; 95% confidence interval, 1.3-3.6; P = 0.004), even when used with other controller therapies.

CONCLUSIONS

Despite having fewer asthma symptoms and less rescue β-agonist use, African-Americans with asthma have more treatment failures compared with whites, especially when taking long-acting β-agonists.

Inflammation and cardiorespiratory control: the role of the vagus nerve

Inflammation and immunity have been implicated in a wide variety of diseases and disorders ranging from asthma to cardiovascular disease to hemorrhagic shock. In this review we will briefly consider the evidence for the neural concomitants of immunomodulation. First, we will briefly review the anatomy and physiology of the cardiorespiratory system. Then we will review the anatomy and physiology of neural-immune communication. The nucleus of the solitary tract is a site of integration of both the afferent and efferent neural regulation of the cardiorespiratory as well as the immune system. Then we will provide an overview of what is known about neuroimmunomodulation from both animal and human studies including neuroimaging and clinical studies. Finally, we will discuss a possible role of this neural circuitry in asthma related health disparities.

Asthma and asthma severity among African American adults in the Jackson Heart Study

The aims of this study were to investigate the baseline prevalence of and risk factors associated with asthma, classify asthma severity, and describe medication use in a population-based sample of African American men and women 21 to 84 years of age from the Jackson Heart Study (JHS). Participants provided responses to respiratory and medical history questions and a medication inventory and underwent spirometry and other clinical examinations. These data were used to examine the extent to which novel and traditional risk factors were associated with asthma. Of the 4,098 participants included in this analysis, 9.4% reported lifetime asthma (5.7% current, 3.7% former), and current asthma was higher in women (6.8%) than in men (3.8%). An additional 9.8% reported an attack of wheeze with shortness of breath or non-doctor confirmed asthma (i.e., "probable" asthma). The mean forced expiratory volume in 1 second (FEV(1))% predicted was lower in those reporting current asthma (women: 83.7 +/- 18.0; men: 75.2 +/- 16.8) compared to those not reporting asthma (women: 95.6 +/- 16.7; men: 91.7 +/- 16.0). Current and probable asthma was associated with lower serum cortisol levels and hypertension medication use, along with traditional risk factors (i.e., lower socio-economic status, higher global stress scores, obesity, and fair to poor perceived general health). Severe asthma was low among participants reporting current (9.8%), former (3.3%), and probable (4.9%) asthma. Asthma medication use was reported by nearly 60% of the participants reporting current asthma. Asthma in African American adults is associated with decreased serum cortisol, hypertension medication use, and considerable lung function impairment compared to those who did not report asthma. The prevalence of asthma in the JHS is lower than state and national estimates, although the estimates are not directly comparable. Furthermore, asthma is drastically underdiagnosed in this population.

A new focus on assessing and treating asthma control in the African-American community: a call to action

Asthma continues to be a highly prevalent disease characterized by significant morbidity, unnecessary mortality, and substantial cost to the health care system. After decades of increasing prevalence, the number of current asthmatics in recent years has plateaued at approximately 22 million people in the United States. An additional 10 million Americans have a past history of asthma that is not active. The burden of asthma is higher among African Americans than in any other racial or ethnic group in America. The African-American community continues to experience a disproportional increase in asthma prevalence, morbidity, and mortality. The educational initiatives stemming from the newly revised National Heart Lung and Blood Institute (NHLBI) guidelines provide the opportunity to address the increased burden of asthma in the African American community. These new guidelines, released in August 2007, focus on asthma control as the primary goal of therapy, routine monitoring of asthma control, and use of asthma control assessments to direct treatment. The present review discusses the following: I. The impact of health disparities on outcomes of African Americans with asthma, II. The barriers that prevent asthmatic patients from achieving optimal control, III. The unique factors that challenge practitioners and patients in achieving optimal asthma control in the African American Community, IV. The impact of good asthma control and the need for patients and clinicians to assess asthma control in with a standardized assessment tool, and V. Strategic initiatives and the role of the End The Attacks NOW program in improving outcomes for African American patients with asthma.

The asthma emergency department visit: treating a crisis in the midst of uncontrolled disease

BACKGROUND

Patients with asthma who require emergency department (ED) care are burdened with asthma symptoms, are at risk for hospitalization, and use expensive resources.

OBJECTIVE

To examine whether an ED-based surveillance system that characterized asthma symptoms and care before, during, and after an ED visit enhances our understanding of the natural history of asthma exacerbations.

METHODS

This cross-sectional follow-up enrolled 225 adult patients who presented to 1 of 6 Illinois EDs for asthma care. Clinical characteristics before ED presentation, care provided in the EDs, and 1-month follow-up status were assessed by self-administered questionnaire, medical record review, and telephone interview, respectively.

RESULTS

Persistent asthma symptoms were reported by 85.8% and 84.9% (P = .37) of patients before their ED visit and follow-up call, respectively. For patients with persistent symptoms before the ED visit and follow-up call, 54.4% and 73.8% (P = .02) reported using an inhaled corticosteroid, respectively. Inhaled corticosteroids were recommended for 49.4% of discharged patients with persistent symptoms. Relapse rates for return ED visits and return hospitalizations were 26.4% and 9.6%, respectively. Patients had low asthma-specific and general quality-of-life scores at follow-up.

CONCLUSIONS

Patients with asthma exacerbations most often had uncontrolled asthma before the ED visit that subsequently deteriorated, temporarily improved with ED treatment, and continued as uncontrolled asthma after the ED visit. Although improvements in care were reported 1 month after the ED visit, opportunities for additional improvement were observed.

Prematurity as a predictor of childhood asthma among low-income children

PURPOSE

The purpose of this study was to evaluate the association among birth weight, prematurity, and the prevalence of asthma later in childhood and to assess the degree to which this association may differ between black and white children.

METHODS

Michigan Medicaid claims data from 2001 through 2003 were analyzed to determine asthma prevalence for 150,204 children between ages 5 and 18 years. Asthma cases were identified using Healthcare Effectiveness Data and Information Set persistent asthma criteria and included children having claims for any of the following services within a calendar year: at least one inpatient or one emergency department (ED) claim with an asthma primary diagnosis; at least four asthma medication-dispensing events; or at least four outpatient visits with an asthma diagnosis, and at least two asthma medication-dispensing events. Birth weight and gestational age from birth certificate data were matched with Medicaid files to determine size-for-gestational-age criteria.

RESULTS

Overall, 8.3% of children had persistent asthma; black children had slightly higher asthma prevalence (8.6%) than white children (7.8%; odds ratio [OR]=1.11, 95% confidence interval [CI]: 1.07-1.15). Children born very preterm (<or=32 weeks) had higher prevalence of childhood asthma (11.7%) compared with term births (8.0%; OR=1.51, 95% CI: 1.40-1.63). However, no significant differences were observed in odds of asthma between black and white children born very preterm, preterm (33-36 weeks), or small for gestational age (SGA).

CONCLUSIONS

Regardless of race, children born very preterm had an increased risk of childhood asthma. Although overall asthma prevalence is higher among black children enrolled in Medicaid compared with their white counterparts, these differences were attenuated when prematurity or SGA status were taken into account.