Modifiable barriers to adherence to inhaled steroids among adults with asthma: it's not just black and white

BACKGROUND: Sociobehavioral factors influence adherence to inhaled corticosteroid (ICS) in adults with asthma and warrant exploration as explanations of apparent racial disparities in adherence. OBJECTIVE: The purposes of this study were to identify barriers to adherence, potentially modifiable by healthcare providers, in a group of African Americans and non-African Americans and to test modifiable barriers as explanations of racial-ethnic differences in adherence. METHODS: We conducted a cohort study of 85 adults (mean age, 47 +/- 15 years; 61 [72%] female; 55 [65%] African American) with moderate or severe persistent asthma to determine modifiable sociobehavioral predictors of adherence. These were knowledge of the function of ICS, patient-perceived adequacy of communication with the provider, social support, attitude (perception of risks/benefits of ICS), depression, and self-efficacy. Adherence was calculated from electronic monitoring data as the mean of the number of doses recorded per 12 hours divided by the number prescribed, truncated at 100%. Past adherence, baseline severity of symptoms, and sociodemographics were treated as fixed confounders in ordinal logistic modeling. RESULTS: Adherence was 60% +/- 30%. In bivariate analyses, favorable attitude to ICS (P =.01) was associated with better adherence. Of immutable predictors, African American race-ethnicity (P =.001), lower educational achievement (P =.01), lower household income (P =.002), and more baseline symptoms (P =.003) were associated with poorer adherence. In multivariable analysis, controlling for immutable predictors, favorable attitude was associated with adherence. Favorable attitude was associated with greater adherence in African Americans and non-African Americans. Controlling for immutable factors, the race-adherence relationship was not mediated by the mutable factors, but economic factors (income and insurance) were mediators. CONCLUSION: Attitude is strongly related to adherence but does not mediate the effect of race-ethnicity.     

Sociodemographic correlates of indoor allergen sensitivity among United States children.

BACKGROUND: Exposure to indoor allergens is associated with asthma morbidity. Nationally, asthma morbidity disproportionately affects socially disadvantaged populations, but it is unclear whether exposure to indoor allergens follows a similar pattern. OBJECTIVE: We sought to examine the national prevalences and demographic correlates of sensitivity to indoor allergens related to asthma. METHODS: Analysis of a cross-sectional survey of a representative sample of 4164 United States children aged 6 to 16 years who participated in allergen testing in the Third National Health and Nutrition Examination Survey from 1988 to 1994 was performed. The main outcome measures were sensitivity reactions to cockroach, dust mite, cat, and Alternaria alternata, as measured via skin prick testing. RESULTS: Multivariate models, including sex, age, race-ethnicity, education, poverty, family history, region of country, housing age, crowding, and urban residence, revealed significant racial-ethnic disparities in sensitivity. Compared with white children, African American children had higher odds ratios (ORs) of cockroach or dust mite sensitivity (cockroach OR, 2.5 [95% CI, 1.9-3.2]; dust mite OR, 1.3 [95% CI, 1.0-1.7]), as did Mexican American children (cockroach OR, 1.9 [95% CI, 1.3-2.8]; dust mite OR, 1.6 [95% CI, 1.2-2.2]). African American children also had significantly higher odds of sensitivity to A alternata (OR, 2.1 [95% CI, 1.5-2.8]). CONCLUSIONS: African American and Mexican American children are substantially more likely than white children to be sensitized to allergens important in asthma. Differences in indoor allergen sensitivity are consistent with racial differences in asthma morbidity. Along with other data, these findings suggest that racial disparities in housing, community, or both environmental factors play a role in determining national patterns of asthma morbidity.     

Qualitative research-enhanced understanding of patients' beliefs: results of focus groups with low-income,urban, African American adults with asthma

BACKGROUND: Qualitative research is an important research methodology for understanding the health beliefs and attitudes of patients. These beliefs and attitudes have been proposed as partial explanations for low adherence to medical therapy and the consequent high burden of morbidity from asthma among low-income urban minorities. OBJECTIVE: The purpose of this study was to explore barriers to adherence to inhaled corticosteroids (ICSs), health beliefs regarding asthma and its treatment, and opinions about providers and clinical research among low-income groups. METHODS: Three focus groups were conducted with 15 low-income, urban, African American adults with persistent asthma. These focus group sessions were audiotaped, transcribed verbatim, and coded by using qualitative analytic techniques. RESULTS: Health beliefs that influenced adherence included patients' reliance on their assessment of asthma control over that of the health provider and concern over the adverse effects of ICS therapy. Adherence was also adversely affected by social obligations and insurers' approval policies and restricted formularies. Although mistrust of the medical establishment was evident, members generally expressed a willingness to participate in nonpharmacologic clinical research and the belief that research was beneficial. However, they had strong preferences for where the research should be conducted. CONCLUSIONS: Although barriers exist to ICS adherence in patient populations, many of these can be addressed during patient-clinician interactions. Qualitative research is an important tool for formulating hypotheses for improving ICS adherence that can then be tested in the future by using quantitative research methods.     

Association between IgE levels and asthma severity among African American, Mexican, and Puerto Rican patients with asthma

BACKGROUND: High levels of IgE are associated with asthma. Whether higher levels of IgE are associated with more severe asthma is still unclear. OBJECTIVE: To determine whether IgE is associated with asthma severity among Latino and African American subjects with asthma. METHODS: We assessed lung function and asthma severity among African American, Mexican, and Puerto Rican patients with asthma with high IgE levels (> or =100 IU/mL; n = 492) and compared these values to those of patients with asthma with low IgE levels (<100 IU/mL; n = 247). We also examined IgE as a continuous variable among these groups. RESULTS: Patients with asthma with high IgE had a lower mean FEV(1) (87.6 +/- 17.1, percent of predicted) than patients with asthma with low IgE (91.5 +/- 17.0; P = .031). Regardless of race and ethnicity, baseline FEV(1), forced expiratory flow, and FEV(1)/forced vital capacity were lower among subjects with high IgE than among subjects with low IgE (P = .031, P < .0001, P = .0001, respectively). In addition, 54.7% of patients with asthma with high IgE had been previously hospitalized, compared with 44.1% of patients with asthma with low IgE (odds ratio, 1.33; 95% CI, 1.04-1.71). CONCLUSION: Higher IgE is associated with lower baseline lung function and more severe asthma among these populations. CLINICAL IMPLICATIONS: Among patients with asthma from 3 ethnically distinct groups, total IgE levels are inversely correlated with baseline lung function and asthma severity.     

Race/ethnicity, language, and asthma care: findings from a 4-state survey.

BACKGROUND: Latino and African American children have poorer asthma control than non-Latino white children, but few studies examine the association among race/ethnicity, language, and specific processes of asthma care. OBJECTIVE: To evaluate the association of race/ethnicity and language with the quality of asthma care. METHODS: A random sample of children from birth to the age of 17 years with asthma within 4 states (California, Texas, Illinois, and Alabama) was selected for the National Asthma Survey conducted by the National Center for Health Statistics from March 1, 2003, to March 10, 2004. Parents completed a telephone survey that included measures of asthma care quality. The final sample was 1,517 children. RESULTS: According to parental report, only 41.4% of children had an asthma management plan and 48.5% were ever advised by a clinician to control asthma by changing the child's home and school environment. African American and Latino children with persistent asthma had lower odds of taking controller medication than non-Latino white children. In multivariate analysis adjusting for annual income, insurance, and age, Latino children with Spanish parental interview, but not African American and Latino children with English parental interview, had poorer experiences with care than white children (ever taught what to do during an attack: odds ratio, 0.4 [95% confidence interval, 0.2-0.6]; and ever advised to change child's home and school environment: odds ratio, 0.5 [95% confidence interval, 0.3-0.8]). CONCLUSIONS: Differences in asthma care quality and controller use persist among racial/ethnic and language groups despite similar rates of planned encounters for asthma. Improving use of controller medications and counseling on environmental modifications are important for reducing asthma disparities.     

Barriers to adherence to asthma management guidelines among inner-city primary care providers

BACKGROUND: Health care provider adherence to national asthma guidelines is critical in translating evidence-based recommendations into improved outcomes. Unfortunately, provider adherence to the National Heart, Lung, and Blood Institute (NHLBI) guidelines remains low. OBJECTIVE: To identify barriers to guideline adherence among primary care professionals providing care to inner-city, minority patients with asthma. METHODS: We surveyed 202 providers from 4 major general medicine practices in East Harlem in New York, New York. The study outcome was self-reported adherence to 5 NHLBI guideline components: inhaled corticosteroid (ICS) use, peak flow (PF) monitoring, action plan use, allergy testing, and influenza vaccination. Potential barriers included lack of agreement with guideline, lack of self-efficacy, lack of outcome expectancy, and external barriers. RESULTS: Most providers reported adhering to the NHLBI guidelines for ICS use (62%) and for influenza vaccinations (73%). Self-reported adherence was 34% for PF monitoring, 9% for asthma action plan use, and 10% for allergy testing. Multivariate analyses showed that self-efficacy was associated with increased adherence to ICS use (odds ratio [OR], 2.8; P = .03), PF monitoring (OR, 2.3; P = .05), action plan use (OR, 4.9; P = .03), and influenza vaccinations (OR, 3.5; P = .05). Conversely, greater expected patient adherence was associated with increased adherence to PF monitoring (OR, 3.3; P = .03) and influenza vaccination (OR, 3.5; P = .01). Familiarity with specific guideline components and higher level of training were also predictors of adherence. CONCLUSIONS: Lack of outcome expectancy and poor provider self-efficacy prevent providers from adhering to national asthma guidelines. Efforts to improve provider adherence should address these specific barriers.     

Ethnic differences in asthma and associated phenotypes: collaborative study on the genetics of asthma.

BACKGROUND: In the Collaborative Study on the Genetics of Asthma, 314 families with 2584 subjects were characterized for asthma and allergy. OBJECTIVE: The purpose of this investigation was to examine clinical heterogeneity observed in asthma and allergic characteristics among 3 ethnic groups (African American, white, and Hispanic family members). METHODS: Pulmonary function parameters and asthma associated phenotypes were compared among the ethnic groups. RESULTS: In comparison with the other groups, African American sibling pairs had a significantly lower baseline FEV(1) percent of predicted (P =.0001) and a higher rate of skin test reactivity to cockroach allergen (P =.0001); Hispanic sibling pairs had significantly more skin reactivity overall (P =.001); and white sibling pairs had significantly lower total serum IgE (P <.05). In addition, there were significantly more relatives with asthma among the African American families than among the white and the Hispanic families (P =.001). CONCLUSION: Although different environmental backgrounds should be considered, these clinical differences could be due to differences in genetic susceptibility among the ethnic groups, such as those suggested by our previous genome screen.     

Eotaxin polymorphisms and serum total IgE levels in children with asthma

BACKGROUND: Eotaxin (chemokine, CC motif, ligand; CCL11) is a potent eosinophil chemoattractant strongly implicated in the pathobiology of asthma. Genetic variation at the CCL11 locus has been correlated with serum total IgE, blood eosinophil counts, and circulating eotaxin protein levels in several case-control asthma studies. Family-based association studies of CCL11 genetic variants have not been reported to date. OBJECTIVE: To evaluate 9 common CCL11 single nucleotide polymorphisms (SNPs) in nuclear families ascertained through patients with asthma participating in the Childhood Asthma Management Program study. METHODS: Single nucleotide polymorphism genotyping was performed by using minisequencing and probe hybridization platforms. Family-based association analysis for asthma and 4 asthma-related intermediate quantitative phenotypes was performed by using FBAT. RESULTS: One SNP, -384A>G, was associated with asthma among African American families (P = .01). CCL11 SNPs and haplotypes were not associated with asthma among white or Hispanic families. Two low-frequency alleles in strong pairwise linkage disequilibrium, -426C and IVS2+199A, were associated with lower serum total IgE levels (P = .0006 and P = .009, respectively) in white families, whereas 2 more common variants, -576C and g.4438C, were associated with higher IgE levels in African American families (P = .01-.04). Haplotype analysis in the white cohort provided additional evidence of association with serum total IgE, implicating 2 haplotypes. No single SNP or haplotype associations were observed with blood eosinophil levels, FEV(1), or airway responsiveness. CONCLUSION: These findings provide further evidence that genetic variation at the CCL11 locus is an important determinant of serum total IgE levels among patients with asthma.     

Risk factors for death in adults with severe asthma

BACKGROUND: Mortality risk in adult asthma is poorly understood, especially the interplay among race, disease severity, and health care access. OBJECTIVE: To examine mortality risk factors in adult asthma. METHODS: In a prospective cohort study of 865 adults with severe asthma in a closed-panel managed care organization, we used structured interviews to evaluate baseline sociodemographics, asthma history, and health status. Patients were followed up until death or the end of the study (mean, 2 years). We used Cox proportional hazards regression to evaluate the impact of sociodemographics, cigarette smoking, and validated measures of perceived asthma control, physical health status, and severity of asthma on the risk of death. RESULTS: We confirmed 123 deaths (mortality rate, 6.7 per 100 person-years). In an analysis adjusted for sociodemographics and tobacco history, higher severity-of-asthma scores (hazard ratio [HR], 1.11 per 0.5-SD increase in severity-of-asthma score; 95% confidence interval [CI], 1.01-1.23) and lower perceived asthma control scores (HR, 0.91 per 0.5-SD increase in perceived asthma control score; 95% CI, 0.83-0.99) were each associated with risk of all-cause mortality. In the same adjusted analysis, African American race was not associated with increased mortality risk relative to white race (HR, 0.64; 95% CI, 0.36-1.14). CONCLUSIONS: In a large managed care organization in which access to care is unlikely to vary widely, greater severity-of-asthma scores and poorer perceived asthma control scores are each associated with increased mortality risk in adults with severe asthma, but African American patients are not at increased risk for death relative to white patients.     

Relationship between adherence to inhaled corticosteroids and poor outcomes among adults with asthma

BACKGROUND: Regular use of inhaled corticosteroids (ICSs) can improve asthma symptoms and prevent exacerbations. However, overall adherence is poor among patients with asthma. Objective To estimate the proportion of poor asthma-related outcomes attributable to ICS nonadherence. METHODS: We retrospectively identified 405 adults age 18 to 50 years who had asthma and were members of a large health maintenance organization in southeast Michigan between January 1, 1999, and December 31, 2001. Adherence indices were calculated by using medical records and pharmacy claims. The main outcomes were the number of asthma-related outpatient visits, emergency department visits, and hospitalizations, as well as the frequency of oral steroid use. RESULTS: Overall adherence to ICS was approximately 50%. Adherence to ICS was significantly and negatively correlated with the number of emergency department visits (correlation coefficient [ R ] = -0.159), the number of fills of an oral steroid ( R = -0.179), and the total days' supply of oral steroid ( R = -0.154). After adjusting for potential confounders, including the prescribed amount of ICS, each 25% increase in the proportion of time without ICS medication resulted in a doubling of the rate of asthma-related hospitalization (relative rate, 2.01; 95% CI, 1.06-3.79). During the study period, there were 80 asthma-related hospitalizations; an estimated 32 hospitalizations would have occurred were there no gaps in medication use (60% reduction). CONCLUSIONS: Adherence to ICS is poor among adult patients with asthma and is correlated with several poor asthma-related outcomes. Less than perfect adherence to ICS appears to account for the majority of asthma-related hospitalizations.     

Race/ethnicity, socioeconomic status and the health of pregnant women

We examined how traditional (income, education) and nontraditional (public assistance, material deprivation, subjective social standing) socioeconomic status (SES) indicators were associated with self-rated health, physical functioning, and depression in ethnically diverse pregnant women. Using multiple regression, we estimated the association of race/ethnicity (African American, Latino, Asian/Pacific Islander (PI) and white) and sets of SES measures on each health measure. Education, material deprivation, and subjective social standing were independently associated with all health measures. After adding all SES variables, race/ethnic disparities in depression remained for all minority groups; disparities in self-rated health remained for Asian/Pacific Islanders. Few race/ethnic differences were found in physical functioning. Our results contribute to a small literature on how SES might interact with race/ethnicity in explaining health.     

Polymorphisms in the myosin light chain kinase gene that confer risk of severe sepsis are associated with a lower risk of asthma

BACKGROUND: Myosin light chain kinase (MYLK) is a multifunctional protein involved in regulation of airway hyperreactivity and other activities relevant to asthma. OBJECTIVE: To determine the role of MYLK gene variants in asthma among African Caribbean and African American populations. METHODS: We performed association tests between single nucleotide polymorphisms (SNPs) in the MYLK gene and asthma susceptibility and total serum IgE concentrations in 2 independent, family-based populations of African descent. Previously we identified variants/haplotypes in MYLK that confer risk for sepsis and acute lung injury; we compared findings from our asthma populations to findings in the African American sepsis and acute lung injury groups. RESULTS: Significant associations between MYLK SNPs and asthma and total serum IgE concentrations were observed in the African Caribbean families: a promoter SNP (rs936170) in the smooth muscle form gave the strongest association (P = .009). A haplotype including rs936170 corresponding to the actin-binding activity of the nonmuscle and smooth muscle forms was negatively associated with asthma (eg, decreased risk) in both the American (P = .005) and Caribbean families (P = .004), and was the same haplotype that conferred risk for severe sepsis (P = .002). RNA expression studies on PBMCs and rs936170 suggested a significant decrease in MYLK expression among patients with asthma with this variant (P = .025). CONCLUSION: MYLK polymorphisms may function as a common genetic factor in clinically distinct diseases involving bronchial smooth muscle contraction and inflammation. CLINICAL IMPLICATIONS: Genetic variants in MYLK are significantly associated with both asthma and sepsis in populations of African ancestry.     

Health-related quality-of-life measures for children with asthma: reliability and validity of the Children's Health Survey for Asthma and the Pediatric Quality of Life Inventory 3.0 Asthma Module.

BACKGROUND: Economically disadvantaged African American youth are especially vulnerable to the effects of pediatric asthma and are at increased risk for difficulties in daily functioning. Measures of health-related quality of life (HRQoL) yield important information regarding the impact of pediatric chronic illness on daily functioning. It is essential to develop and validate measures of HRQoL to detect the impact of asthma on this vulnerable population. OBJECTIVE: To examine the psychometric properties of 2 asthma-specific measures of pediatric HRQoL in a sample of economically disadvantaged African American children diagnosed as having asthma. METHODS: One hundred twenty-seven caregivers completed questionnaires regarding their child's HRQoL, asthma symptoms, health care utilization, and school absences and regarding caregiver emotional distress. The severity of the child's asthma was measured via spirometry. RESULTS: The Children's Health Survey for Asthma and the Pediatric Quality of Life Inventory 3.0 Asthma Module demonstrated adequate internal consistency reliability and validity for the present sample. Lower HRQoL was associated with poorer adherence and more health care utilization, asthma symptom days, school absences, and caregiver distress. Only the Children's Health Survey for Asthma was significantly associated with severity, when defined as airway obstruction. CONCLUSIONS: This study supports the psychometric equivalence of 2 condition-specific measures of HRQoL in a population at high risk for asthma and asthma-related problems. The utility of each measure will depend on the needs of the researcher or physician. Both measures can inform the treatment course, help identify and address barriers to treatment adherence, and inform treatment interventions.     

Inhaled corticosteroids and augmented bronchodilator responsiveness in Latino and African American asthmatic patients.

BACKGROUND: National asthma guidelines recommend that patients with persistent asthma regularly use an inhaled corticosteroid (ICS) in addition to as-needed albuterol, yet recent debates question whether this combination is equally efficacious in all ethnicities. OBJECTIVE: To examine the effect of ICS use on bronchodilator responsiveness to albuterol in 3 different ethnic populations. METHODS: A cross-sectional study of 106 Mexican Americans, 246 Puerto Ricans, and 163 African Americans with physician-diagnosed persistent asthma. Asthma severity, ethnicity, and medication use were evaluated using spirometry and questionnaires. Percentage change in forced expiratory volume in 1 second (FEV) was compared in patients who used ICSs vs those who used a short-acting beta2-agonist as their only asthma medication. RESULTS: Inhaled corticosteroid use was associated with improvements in the percentage change in FEV1 after albuterol administration in Mexican Americans (21.7%, P = .01) and Puerto Ricans (18.5%, P = .02) but not in African Americans (3.0%, P = .73). CONCLUSIONS: Inhaled corticosteroid use is associated with augmented bronchodilator responsiveness to albuterol in Mexican Americans and Puerto Ricans, but not in African Americans, with persistent asthma. This underscores the need for an improved understanding of ethnic-specific drug-drug interactions, particularly in those subgroups experiencing the highest burden of asthma morbidity and mortality in the United States.     

Comparison of patterns of allergen sensitization among inner-city Hispanic and African American children with asthma.

BACKGROUND: Among Hispanics, the largest minority ethnic group in the United States, asthma prevalence is increasing, particularly in inner-city neighborhoods. Although allergen sensitization among asthmatic African Americans has been extensively studied, similar details are not available for Hispanic children. OBJECTIVES: To examine patterns of allergen sensitization, including the association with illness severity, in asthmatic children overall and in Hispanic and African American children living in a socioeconomically disadvantaged area of New York City. METHODS: A retrospective medical record review of asthmatic children attending a community hospital in the South Bronx area of New York City was performed. Information abstracted included demographics, asthma severity classification, reported exposures to indoor allergens, and results of allergy testing. RESULTS: Among 384 children in the analysis, 270 (70.3%) were Hispanic and 114 (29.7%) were African American. Sensitization to indoor and outdoor allergens, respectively, did not differ between Hispanic (58.5% and 27.0%) and African American (58.8% and 32.6%) children. Allergen sensitization exhibited a direct, significant association with asthma severity for indoor allergens for the 2 ethnic groups combined and for Hispanics separately but not between asthma severity and outdoor allergens (P < .01). No correlation was found between self-reported allergen exposure and sensitization. CONCLUSIONS: Patterns of allergen sensitization among inner-city Hispanic asthmatic children resemble those among African American children, a finding that is likely explained by the similarity in levels of environmental exposures. With the increasing prevalence of asthma among inner-city Hispanic children, skin testing should be used frequently for objective evaluation of asthma in this ethnic group.     

Disparities in risk communication: a pilot study of asthmatic children, their parents, and home environments

Parents' knowledge and control of asthma triggers in home environments can help reduce risks associated with asthmatic children's respiratory health. This pilot study used both qualitative and quantitative methods to determine parental knowledge of their children's asthma triggers in home environments, control of those triggers, and information received and trusted. Twelve parents of asthmatic children in the greater Pittsburgh area--8 white and 4 African American--participated in one-on-one interviews about home exposures to asthma triggers. All parents described the link between asthma symptoms and both environmental tobacco smoke (ETS) and pet dander exposures. House dust mites and mold were also commonly identified asthma triggers. All 8 white parents reported receiving information from physicians about controlling home environmental triggers of asthma, but the 4 African American parents reported having received no such information. However, all 12 parents reported having greater trust in information received from physicians than from other sources. White parents were significantly more aware of potential asthma triggers and performed significantly more actions to control the triggers in their homes. African American parents noted stressful experiences with primary and secondary care, less recall of information sharing about asthma triggers, and a focus on symptom management vs trigger avoidance.     

Ethnicity moderates the influence of perceived social status on subjective sleep quality

It has long been recognized that socioeconomic status (SES) influences health and health-related behaviors, and it has been suggested that the adverse impact of low SES on health may be partly mediated by poor sleep quality. The relation between sleep and objective and subjective measures of SES has only been explored in a preliminary manner, providing indirect evidence that associations between SES and health might be explained, in part, by disrupted sleep. However, it remains unclear whether low SES directly affects sleep quality or whether the SES-sleep quality relation varies as a function of ethnicity given robust ethnic disparities across SES-related factors. This study examined the relation between perceived social status (i.e., individuals' perception of their socioeconomic standing) and subjective sleep quality among 149 college students, and examined the moderating effect of ethnicity to determine whether the magnitude or direction of association differed among Caucasian, Asian, and African Americans. Using hierarchical regressions and a dummy-coded ethnicity variable, results demonstrated significant moderation (ΔR? = 0.04, p = .02), such that both Asian (p = .04) and African Americans (p = .02) were significantly different from Caucasian Americans. Lower perceived social status was related to greater impairment in sleep quality for Asian Americans (β = -.37, p < .01) and African Americans (β = -.51, p < .01), but not Caucasian Americans (β = -.02, p = .87). These findings provide initial support for the negative impact of low perceived social status on sleep quality for specific subgroups of ethnic minorities.