Racial-Ethnic Differences in Childhood Asthma Treatment Eric M. Sarpong and G. Edward Miller AHRQ Conference September 20, 2011

Introduction Asthma – chronic, complex and costly health condition Asthma – chronic, complex and costly health condition – Estimated costs of asthma in the U.S. - $19.7 billion (NHLBI, 2007) Why childhood asthma medication use? Why childhood asthma medication use? – Recent significant increases in: Treated prevalence Treated prevalence Health care and prescribed asthma drug expenditures ( Miller & Sarpong ) Health care and prescribed asthma drug expenditures ( Miller & Sarpong ) – Recent changes in asthma care Treatment guidelines (NAEPP-EPR3, 2007) - Inhaled corticosteroid (ICS); preferred first-line therapy for persistent asthma Treatment guidelines (NAEPP-EPR3, 2007) - Inhaled corticosteroid (ICS); preferred first-line therapy for persistent asthma – Changes in use and availability of new pharmacotherapies Increased use of controller medications Increased use of controller medications Decreased use of mono-therapy with relievers Decreased use of mono-therapy with relievers Differences in asthma treatment persists Differences in asthma treatment persists

Pharmaceutical Treatment of Asthma Recommended treatment depends on asthma severity (NAEPP-EPR3, 2007) Recommended treatment depends on asthma severity (NAEPP-EPR3, 2007) – Controllers (e.g., inhaled corticosteroid) Used in managing asthma symptoms, by minimizing inflammation and reducing the risk of serious exacerbations Used in managing asthma symptoms, by minimizing inflammation and reducing the risk of serious exacerbations Recommended for all children with persistent asthma Recommended for all children with persistent asthma – Relievers (e.g., inhaled short acting beta agonists) Used in managing moderate or severe asthma attacks by promptly relaxing airway muscles Used in managing moderate or severe asthma attacks by promptly relaxing airway muscles Recommended for all children with intermittent asthma Recommended for all children with intermittent asthma

Treated Prevalence of Childhood Asthma by Race-Ethnicity, Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites significant at p <.05.

Use of Controllers Among Children With Treatment for Asthma, Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites significant at p <.05.

Use of Relievers Only, Among Children with Treatment for Asthma, Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites significant at p <.05.

Differences in Treated Prevalence and Use of Asthma Medications NH Black children - more likely than NH White and Hispanic children to be treated for asthma NH Black children - more likely than NH White and Hispanic children to be treated for asthma NH Black and Hispanic children - less likely than NH White children to use controllers NH Black and Hispanic children - less likely than NH White children to use controllers NH Black and Hispanic children - more likely than NH White children to use relievers only NH Black and Hispanic children - more likely than NH White children to use relievers only

Previous Research Large body of literature with mixed evidence on differences in children’s use of asthma medication Large body of literature with mixed evidence on differences in children’s use of asthma medication Some studies find no differences by race-ethnicity, others do find a difference Some studies find no differences by race-ethnicity, others do find a difference Studies differ on a number of dimensions Studies differ on a number of dimensions – Time period – Population (e.g., Medicaid, private claims, nationally representative) – Degree to which they control for differences in underlying characteristics across groups

Research Objective and Contribution Research Objective Research Objective – Examine differential use of asthma medication by race- ethnicity – Examine extent to which differences in mean predisposing, enabling and need characteristics explain differences in use New Contribution New Contribution – Previous literature limited - Medicaid data, administrative data or community samples, key variables unavailable – Comprehensive look at differences using nationally representative data (MEPS) – Provide descriptive information on reasons for differences and possible approaches to addressing these differences

Analytic Approach Describe differences in controllers and relievers only use by race-ethnicity Describe differences in controllers and relievers only use by race-ethnicity Estimate pooled regression models with binary outcomes (i.e., controllers and relievers only) Estimate pooled regression models with binary outcomes (i.e., controllers and relievers only) – Explanatory variables Predisposing (e.g., socio-demographics, geographic) Predisposing (e.g., socio-demographics, geographic) Enabling (e.g., health insurance, family income/structure and parental education/employment status) Enabling (e.g., health insurance, family income/structure and parental education/employment status) Need (e.g., health status, co-occurring conditions) Need (e.g., health status, co-occurring conditions) Use Oaxaca-Blinder method - decompose differences into: Use Oaxaca-Blinder method - decompose differences into: – Explained - differences due to mean differences in explanatory variables – Unexplained - differences due to differences in estimated coefficients

Data Data Data – Medical Expenditure Panel Survey (MEPS) Population studied Population studied – Insured children (ages 0-17) with reported treatment for asthma Treatment = health service use associated with asthma Treatment = health service use associated with asthma – Sample size N = 813 NH White children N = 813 NH White children N = 608 NH Black children N = 608 NH Black children N = 644 Hispanic children N = 644 Hispanic children Drugs Drugs – Link MEPS drug data by NDC to the Multum Lexicon – Use generic names to categorize drugs as controllers or relievers – Measures: any use of controllers and relievers only

Descriptive Results - Differences in Mean Characteristics NH Black children more likely than NH White children to NH Black children more likely than NH White children to – Be covered by public insurance, live in an MSA and in the south (predisposing) – Live in families with low levels of family income, low parental education, unmarried parent and unemployed parent (enabling) – Be in fair/poor physical health (need) Hispanic children more likely than NH White children to Hispanic children more likely than NH White children to – Be covered by public insurance, live in an MSA, in the west, have non-native parents and parents with risky attitudes towards health (predisposing) – Live in families with low levels of family income, low parental education, unmarried parent, unemployed parent and live in a larger family (enabling) – Be in fair/poor physical health (need)

Multivariate Results - Predictors of Controller and Reliever Only Use Positive effects on controller use Positive effects on controller use – Age 5-11, native parents, married parent, fair/poor physical health, and having treatment for allergies Negative effects on controller use Negative effects on controller use – Female, MSA, western region, low family income, parental education, and large family Positive effects on reliever only use Positive effects on reliever only use – Female, MSA, western region, native parents, low family income, and large family Negative effects on reliever only use Negative effects on reliever only use – Age 5-11, married parent, fair/poor physical health, and having treatment for allergies Results are based on coefficient estimates from pooled linear probability models.

Oaxaca-Blinder Decomposition - NH Whites vs. NH Blacks, Controllers Important variables Enabling Low income Low income ≤ High school ≤ High school Family of > 4 Family of > 4 Unmarried Unmarried Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites, significant at p <.10. Explained

Oaxaca-Blinder Decomposition Results - NH Whites vs. NH Blacks, Relievers Only Important variables Enabling Low income Low income Family of > 4 Family of > 4 Unmarried Unmarried Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites, significant at p <.10. Explained

Oaxaca-Blinder Decomposition Results - NH Whites vs. Hispanics, Controllers Important variables Predisposing MSA MSA West West Non-native parents Non-native parentsEnabling Low income Low income ≤ High school ≤ High school Family of > 4 Family of > 4 Unmarried Unmarried Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites, significant at p <.10. Explained

Oaxaca-Blinder Decomposition Results - NH Whites vs. Hispanics, Relievers only Important variables Enabling Low income Low income ≤ High school ≤ High school Family of > 4 Family of > 4 Unmarried Unmarried Source: MEPS, Estimates for insured children with reported treatment for asthma. Differences from NH Whites, significant at p <.10. Explained

Interpretation of Oaxaca-Blinder Decomposition Results Several characteristics in the domains of the behavioral model were associated with Several characteristics in the domains of the behavioral model were associated with – Controller use – Reliever only use Our model Our model – Explained most differences in: Controller use for NH Blacks and Hispanics Controller use for NH Blacks and Hispanics Reliever only use for Hispanics Reliever only use for Hispanics – Differences in reliever only use for NH Blacks, largely unexplained Unobservable factors - differences in responses to characteristics, may be important Unobservable factors - differences in responses to characteristics, may be important

Limitations and Future Research Limitations Limitations – No measure of asthma severity Results may change if severity differs across groups Results may change if severity differs across groups – Non-causal descriptive model Future research Future research – Depart from linear probability models – Use non-parametric approach Raking (Pylypchuk and Selden, 2008, JHE) Raking (Pylypchuk and Selden, 2008, JHE) – Follow previous approaches Kirby et al, 2010 MCRR and Hudson et al, 2007 Kirby et al, 2010 MCRR and Hudson et al, 2007

Conclusions Non-Hispanic whites: low asthma treated prevalence and reliever only use and, higher controller use Non-Hispanic whites: low asthma treated prevalence and reliever only use and, higher controller use Enabling factors explained some, not all, of the differences in controller and reliever only use for NH Blacks and Hispanics Enabling factors explained some, not all, of the differences in controller and reliever only use for NH Blacks and Hispanics Predisposing factors explained some of the differences in controller use for Hispanics Predisposing factors explained some of the differences in controller use for Hispanics Some unobservable characteristics may have also played a role Some unobservable characteristics may have also played a role Results are consistent with studies in other therapeutic classes of drugs and disease areas Results are consistent with studies in other therapeutic classes of drugs and disease areas

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