Robert S. Valet

Rural health disparities in asthma care and outcomes

Fifty-nine million Americans (21% of the US population) live in rural areas of the United States. Compared with persons living in urban areas of the United States, rural populations have lower income, a higher rate of government versus private insurance, and decreased access to health care. Although there are reports of lower asthma prevalence in rural areas, the majority of these data have been published on international populations, with few available studies looking at American urban versus rural asthma prevalence on a national scale or comparing rural with nearby urban cohorts in the United States. A large body of literature, mainly generated from studies of rural Europe, suggests that lower prevalence might be due to beneficial effects of exposure to farm environments, but the extent to which this applies to the rural United States, where a smaller proportion of the population engages in farming, is unclear. The United States has the additional covariate of having a higher proportion of African Americans, who have a greater asthma burden than whites independent of socioeconomic status, clustered in cities. There are data indicating that rural patients have increased difficulty obtaining health care in general and limited data suggesting that they receive inferior care for asthma. Future work is needed to more clearly define asthma prevalence and morbidity among residents of the rural United States, as well as to identify interventions effective in this population.

High asthma prevalence and increased morbidity among rural children in a Medicaid cohort.

BACKGROUND Urban children represent a group at high risk for asthma development and adverse asthma outcomes. Although rural children also encounter sociodemographic disparities that might be expected to worsen asthma, asthma in the rural United States is poorly studied. OBJECTIVES To determine rural-urban differences in childhood asthma diagnosis and morbidity. METHODS We studied a statewide population of 117,080 children continuously enrolled in Tennessee Medicaid from birth through the sixth year of life, using linked Tennessee Medicaid, vital records, and pharmacy claims databases to determine asthma diagnosis and residence. RESULTS The cohort was 45% urban, 23% suburban, and 33% rural. Compared with urban children, rural children were more likely to be white, have a history of bronchiolitis, and have mothers who smoked. Eleven percent of urban, 12% of suburban, and 13% of rural children met study criteria for asthma diagnosis (adjusted odds ratio for rural children, 1.16; 95% confidence interval, 1.09-1.24; adjusted odds ratio for suburban children, 1.22; 95% confidence interval, 1.14-1.30; with urban as the referent; P < .001). Rural children had greater use of outpatient asthma care, whereas urban children had greater use of inhaled corticosteroids. Compared with urban children, rural children had fewer asthma emergency department visits but were hospitalized for asthma at similar rates and had similar use of asthma rescue medications. CONCLUSION In this pediatric Medicaid population, rural children had increased asthma prevalence and similar asthma morbidity compared with urban children but differences in patterns of asthma care and resource use, suggesting that optimal interventions for asthma may differ in rural compared with urban populations.

Objectives, design and enrollment results from the Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure Study (INSPIRE)

BackgroundRespiratory syncytial virus (RSV) lower respiratory tract infection (LRI) during infancy has been consistently associated with an increased risk of childhood asthma. In addition, evidence supports that this relationship is causal. However, the mechanisms through which RSV contributes to asthma development are not understood. The INSPIRE (Infant Susceptibility to Pulmonary Infections and Asthma Following RSV Exposure) study objectives are to: 1) characterize the host phenotypic response to RSV infection in infancy and the risk of recurrent wheeze and asthma, 2) identify the immune response and lung injury patterns of RSV infection that are associated with the development of early childhood wheezing illness and asthma, and 3) determine the contribution of specific RSV strains to early childhood wheezing and asthma development. This article describes the INSPIRE study, including study aims, design, recruitment results, and enrolled population characteristics.Methods/designThe cohort is a population based longitudinal birth cohort of term healthy infants enrolled during the first months of life over a two year period. Respiratory infection surveillance was conducted from November to March of the first year of life, through surveys administered every two weeks. In-person illness visits were conducted if infants met pre-specified criteria for a respiratory illness visit. Infants will be followed annually to ages 3-4 years for assessment of the primary endpoint: wheezing illness. Nasal, urine, stool and blood samples were collected at various time points throughout the study for measurements of host and viral factors that predict wheezing illness. Nested case-control studies will additionally be used to address other primary and secondary hypotheses.DiscussionIn the INSPIRE study, 1952 infants (48% female) were enrolled during the two enrollment years and follow-up will continue through 2016. The mean age of enrollment was 60 days. During winter viral season, more than 14,000 surveillance surveys were carried out resulting in 2,103 respiratory illness visits on 1189 infants. First year follow-up has been completed on over 95% percent of participants from the first year of enrollment.With ongoing follow-up for wheezing and childhood asthma outcomes, the INSPIRE study will advance our understanding of the complex causal relationship between RSV infection and early childhood wheezing and asthma.

Increased healthcare resource utilization for acute respiratory illness among Latino infants.

OBJECTIVE To examine healthcare resource utilization for acute respiratory illness in Latino infants compared with other racial/ethnic groups. STUDY DESIGN We studied 674 term-born, previously healthy infants brought in for an unscheduled healthcare visit for an acute respiratory illness. The predictor variable was infant race/ethnicity, and the primary outcome was healthcare resource utilization, adjusted for age and disease severity. RESULTS The cohort was 14% Latino, 52% white, 22% African American, and 12% other race/ethnicity. More than one-third (37%) of the mothers of Latino infants were Spanish-speaking. The bronchiolitis severity score was higher (indicating more severe disease) in white infants (median, 6.0; IQR, 3.0-9.0 on a scale of 0-12) compared with Latino (median, 3.0; IQR, 1.0-6.0) and African American (median, 3.5; IQR, 1.0-6.0) infants (P < .001 for the comparison of all groups). Disease severity was similar in Latino and African American infants (P = .96). Latino infants were the most likely to receive antibiotics (58%, compared with 47% of whites and 34% of African Americans; P = .005) and to have body fluid cultures drawn. Latino infants also were more likely than African American infants to undergo chest radiography and respiratory virus rapid antigen testing (P ≤ .01). Latino infants from Spanish-speaking families had a higher rate of respiratory syncytial virus testing compared with those from English-speaking families (76% vs 51%; P = .016). CONCLUSION Providers caring for Latino infants with acute respiratory illness ordered more antibiotics and diagnostic testing for this group, particularly compared with African Americans, even though the 2 groups had similar disease severity and socioeconomic disparities. Language barrier may be a possible explanation for these differences.

Prevalence and characteristics of medication sharing behavior in a pediatric Medicaid population with asthma

Few studies have examined sharing or borrowing of non-addicting prescription medications (references 1–6; reviewed in reference 7) and no study has looked at this behavior in patients with asthma. We hypothesized that medication sharing/borrowing would be common in families with children with asthma and be associated with worsened asthma control, and undertook this investigation to describe features surrounding this behavior and examine its effect on adverse asthma outcomes. We studied 112 children enrolled from primary care or pediatric pulmonology clinic at the Vanderbilt University site of a larger study regarding barriers to asthma medication adherence. Eligible children were aged 4–11 years, insured under Tennessee Medicaid (TennCare), and carried a chart reviewed physician’s diagnosis of asthma, with a controller medication prescribed in the previous year. The child and caregiver completed an interview including an Asthma Control Test (ACT) score (for ages 4–11 years),8 and questions about asthma adverse events, asthma controller adherence, and medication sharing/borrowing behaviors. Medication sharing (“Sometimes patients share medicine that a doctor prescribed with someone else. In the last year, have you ever given your child’s prescription medicine for asthma or allergy to someone else?”) and borrowing (“In the last year, has your child ever taken a dose of a medicine for asthma or allergy that was prescribed for someone else?”) were determined by parental report, using questions modeled on those utilized in previous studies.3,6,7 We examined, by sharing/borrowing status, subjects’ ACT scores, reported emergency department (ED) or asthma acute care visits in the past 6 months, rescue inhaler usage, and reported asthma controller medication adherence in the past week. Parents provided written informed consent, and the protocol was approved by the Institutional Review Board of Vanderbilt University. A total of 112 children were studied. The cohort was 52% African-American, 29% white, 3% Asian, and 14% other or >1 race; 20% were of Latino ethnicity. The cohort had a slight male predominance (64%), and mean age was 7.8 years (range 4–11 years). Sixty percent of families had yearly income <

β-AGONIST USE AS AN INDICATOR OF CHANGE IN ASTHMA CONTROL DURING PREGNANCY

20,000, and 92% had yearly income <

Respiratory Severity Score Separates Upper Versus Lower Respiratory Tract Infections and Predicts Measures of Disease Severity.

40,000. Parents of 18 children (16%) reported that their child either shared or borrowed prescription asthma or allergy medication in the preceding year; parents of 13 children (12%) reported borrowing someone else’s medication, and parents of 11 children (10%) reported sharing their child’s medication with someone else. (Table 1) The most common medications to share/borrow were short acting beta agonists (SABA), leukotriene antagonists, inhaled corticosteroids (ICS), and inhaled corticosteroid-long acting beta agonists (ICS-LABA); no subjects reported sharing/borrowing antibiotics or oral corticosteroids. Sharing/borrowing among siblings or with other family members accounted for nearly all reported instances. Reasons cited for sharing/borrowing medication are listed in Table 1. Table 1 Features of asthma and allergy medication sharing/borrowing in the preceding year among 18 asthmatic children whose parent reported this behavior. Among those who shared/borrowed asthma/allergy medication, median ACT (interquartile range) was 17 (13.2–21.5) compared with 20 (17–22) among those who did not share/borrow, p=0.14 (Table 2). Among those who shared/borrowed, 67% had an ACT ≤19 (suggesting uncontrolled asthma8) compared with 43% of those who did not share/borrow, p=0.066. Rate of reporting one or more ED or acute care visits for asthma in the previous 6 months, and reported usage of rescue inhalers in the previous 14 days, did not differ by medication sharing/borrowing status. Finally, there was no difference by sharing/borrowing status in reported adherence to asthma controller medications over the week preceding the survey (median reported usage of ICS, ICS-LABA, and leukotriene modifier medications among those who did and those who did not share/borrow was 7 out of 7 days). Table 2 Measures of asthma control by asthma/allergy medication sharing/borrowing status. Asthma is a major cause of childhood morbidity, and disproportionately affects disadvantaged persons, including minorities and those of low socioeconomic status.9 A factor that has not been studied previously that might influence asthma outcomes is sharing or borrowing of prescription asthma and allergy medications. Among a population of Medicaid-enrolled children with asthma, 16% of families reported engaging in this behavior in the year preceding the survey. Nearly all sharing/borrowing was among family members, particularly between siblings, and most frequently involved rescue inhalers and asthma controllers. Previous studies2,4,6–7 of non-recreational medication sharing/borrowing found that one-time or short duration medications (e.g. antibiotics, oral antihistamines, pain medications) were most frequently shared; interestingly no family reported sharing/borrowing antibiotics or oral corticosteroids. This may relate to the cohort being of lower socioeconomic status, since previous studies of medication sharing have suggested that young adult, white, more educated individuals comprise the group that feels most competent to self-medicate.6 For reasons that likely include that the cohort is of low socioeconomic status and most subjects qualify for free or very low co-pay prescriptions10, asthma and allergy medication sharing/borrowing was somewhat less frequent than in previous studies, impacting our ability to detect differences in asthma control and controller medication adherence. There was a trend toward decreased ACT and a higher proportion with ACT ≤19 among those who shared/borrowed medication, although not significant at the 0.05 level. This study has several limitations. First, sharing/borrowing behavior, asthma adverse events, and controller medication adherence were based upon parental report. Language validating sharing/borrowing behavior was included in the questionnaire (“Sometimes patients share medicine…”), and questions were modeled on those used in previous studies3,6,7 that have examined medication sharing/borrowing, but it is likely that this practice is underreported. Asthma controller medication adherence was likely overreported, and future studies may benefit from inhaler dose counters or other confirmatory measures. Regarding asthma adverse events, a validated objective measure of asthma control (ACT) was included, and questions about sharing/borrowing were asked last, to minimize recall bias. Finally, this study was intended to be primarily descriptive about the prevalence and features of medication sharing/borrowing among children with asthma, and the sample size did not allow for detection of small differences in asthma control. Nevertheless, this is the first study to our knowledge to examine prescription asthma and allergy medication sharing/borrowing among any population with asthma, and suggests that this is a relatively common issue, even when self-reported. Future studies should examine the prevalence of this practice among other populations of asthmatics, and define whether this practice impacts asthma control and asthma controller medication adherence.

Gastroesophageal Reflux Disease Increases Infant Acute Respiratory Illness Severity, but not Childhood Asthma

Asthma is a common chronic disease that affects care during pregnancy in approximately 8% of pregnant women.1 Asthma during pregnancy has adverse effects on both mothers and infants, including increased risk for preeclampsia, pregnancy-induced hypertension, preterm delivery, and birth weight of less than 2,500 g.2,3 A commonly quoted generalization based on data from several small and select study populations is that the course of asthma worsens in one-third of pregnant women, improves in one-third, and remains unchanged in one-third.4 In a large population-based cohort, we studied 8,149 pregnant women with asthma from a larger group of 112,171 pregnant white and black women aged 15 to 44 years who were enrolled in TennCare, Tennessee’s Medicaid managed care program from 1995 to 2001 and who had at least 180 days of continuous enrollment before their last menstrual period. The 112,171 eligible women represented 48% of all deliveries to women enrolled in Tennessee Medicaid and 21% of all live births in Tennessee during the study period. Data were obtained from linked Tennessee Medicaid database and vital records files, providing information on maternal demographics, International Classification of Diseases, Ninth Revision (ICD-9) diagnoses, and pharmacy claims. The protocol was approved by the institutional review boards of Vanderbilt University and the Tennessee Department of Health. A more complete discussion of these methods is contained in the article by Enriquez et al.5 Asthma control was defined by use of short-acting β-agonists. Pharmacy claims containing short-acting β-agonist dose and days of supply were available for all study participants from 25 weeks before last menstrual period until the end of pregnancy. These data were used to determine short-acting β-agonist use for each week from 20 weeks before last menstrual period through the last full week of pregnancy or 40 weeks. Women were classified as current users for each week that was within 30 days of their last dispensed prescription; otherwise, they were classified as nonusers for that week. In Figure 1 (bottom), 95% confidence bands were estimated by bootstrap simulations.6 Figure 1 Effect of pregnancy on asthma control as measured by short-acting β-agonist use. Top, Proportion of white and black women whose β-agonist use increased or decreased during pregnancy. Black women had a significantly greater increase in ... Among the 8,149 pregnant asthmatic women, 77% used short-acting β-agonists during follow-up. Overall, pregnant women had an initial decrease in β-agonist use in the first trimester before experiencing peak use in the third trimester, with 31.8% experiencing worsening asthma control, 31.4% experiencing unchanged asthma control (defined as <5% variation from baseline), and 36.8% experiencing improved asthma control during pregnancy. Changes in use for black and white women are given in Figure 1 (top). Figure 1 (center) shows that asthma control improves during the first half of pregnancy and then worsens. Among pregnant white women control improves during the first half of pregnancy and then reverts to control similar to baseline (Figure 1). However, black women show little change in asthma control in the first 20 weeks and then experience worsening control in the last half of their pregnancy. The initial decrease in albuterol use early in pregnancy is consistent with previous work, from both our group and other groups, showing that despite national guidelines that recommend continuation of maintenance asthma medications,7 use of inhaled corticoste-roids and rescue medications decreases overall during pregnancy.5 Alternatively, consistent with prior work,8 the group whose asthma improved may have experienced the improvement early in pregnancy, resulting in decreased overall use in this interval. The rebound in albuterol use early in the third trimester may be attributable to previously stopping use of controller medications or may be partly attributable to the physiologic effects of pregnancy on asthma control.4 Finally, the racial differences in worsening asthma control during the third trimester compared with prepregnancy seen in blacks but not whites is important and requires further study. We present the first study of the time course and trends in asthma control during pregnancy in a large population-based cohort. This study affirms the classic adage about change in asthma severity during pregnancy, with approximately one-third of pregnant women showing improved control, one-third experiencing worsened control, and one-third remaining unchanged, as measured by change in pharmacy claims for short-acting β-agonist prescriptions. This pattern is similar for both blacks and whites; however, compared with their prepregnancy states, black women were more likely to have worsened asthma control during pregnancy than white women.