HP4 Dose Medicaid Expansion Provide Affordability of Helathcare Service for Asthma Population


      The purpose of this analysis is to estimate the impact of Medicaid expansion in 2014 on healthcare services among asthma patients.


      A retrospective cross-section study was conducted among asthma patients aged 26-64 years in the United States between 2007-2018 using the Medical Expenditure Panel Surveys. The total expenditure and utilization of healthcare services, including prescription drugs, emergency department (ED) visits, hospital inpatients stay, outpatient department visits, office-based medical provider visits, and home health visits, served as the outcome variables. The study sample included 9,564 adults identified as having asthma by Clinical Classifications Software (CCS) disease categorization scheme. We excluded individuals who were covered by Medicare. We estimated a difference-in-difference (DID) design compared two outcomes of patients under 138% federal poverty level (FPL) and upper 138% FPL before and after the Medicaid expansion. The expenditures of healthcare services were estimated by two-part model with logit in the first part and generalized linear model in the second part. The utilization was estimated by negative binomial regression. Other covariates were included to adjust potential confounding factors. Expenditures were inflated to 2018 US dollars as a common year by using the Medical Care component of the Gross Domestic Product (GDP) price index. Estimates were survey-weighted and adjusted for complex multi-stage sampling design.


      A significant difference was found in asthma prescription drug expenditure and utilization. The DID estimates indicated that the Medicaid expansion increased expenditure by $344.39 (p<0.001) and utilization by 2.15 claims (p<0.001) for asthma population under 138% FPL after Medicaid expansion. Expenditures of outpatient department visits decreased by 65.9% (p<0.01) for asthma population under 138% FPL after Medicaid expansion.


      Medicaid expansion were benefit to asthma patients under 138% FPL, especially on prescription drug utilization.