The Role of Health Insurance, Race/ethnicity, and Income in Total Medical Expenditure for Asthma Care

Rationale: Asthma is a chronic disease that affects quality of life, productivity at work and school, and healthcare utilization; although controllable, it can even result in death. To control asthma symptoms and prevent severe asthma attacks, the evidence-based guidelines developed by medical professionals should be followed. These recommendations include assessment of asthma severity, prescribing and ensuring adherence to asthma control medications, providing asthma self-management education, and identifying and avoiding ambient and indoor environmental triggers. In this paper, we estimated the effect of health insurance status, race/ethnicity, and income on asthma-related incremental medical expenditure.

Methods: The primary source of data was the 2008-2013 household component of the Medical Expenditure Panel Survey. We defined treated asthma as the presence of at least one medical or pharmaceutical encounter or claim associated with asthma. For the main analysis, we applied two-part regression models to estimate asthma-related annual per-person incremental medical expenditure (APIME). Routine outpatient care was defined as scheduled nonemergency physician office visits or hospital outpatient visits.

Results: During 2008-2013 the national average of APIME in the United States was $3,266 (in 2015 US dollars); more than 80% of that amount was attributable to prescription medication and routine outpatient care, while roughly 20% was attributable to hospitalizations and emergency room (ER) visits. APIME was significantly lower than the national average for uninsured persons, Blacks, Hispanics, and persons whose income was equal to or above the national poverty level. Conversely, APIME was higher than the national average for insured persons, Whites, Asians, and for those whose income was below the national poverty level. Studies show that use of ERs and hospitalization services, previously a major driver of high total medical expenditures for asthma, occurs more often among uninsured persons, Blacks, and Hispanics. Our study shows that prescription medications and routine outpatient care are comprising an increasingly large proportion of total asthma care expenditure. Uninsured persons may tend to seek care through use of the ER or hospitalization services rather than through routine outpatient care and filling prescription medications, which lowers overall total medical expenditure for asthma care.

Our results also show that persons with income below the national poverty level have higher APIME than persons in higher income brackets. These persons are more likely to live in areas with a higher concentration of outdoor and indoor environmental asthma triggers, which are a major cause of asthma attacks. On the other hand, these individuals are more likely to qualify for Medicaid, which may facilitate access to a wider range of routine and urgent medical services, contributing to higher total medical cost for asthma care.

Conclusion: Lack of health insurance hinders access to prescription medications and routine outpatient care and, as a result, contributes to higher use of ER visits and hospitalizations for persons with asthma. Persons with income lower than the national poverty level have higher APIME and, despite being potentially eligible for Medicaid, may need additional financial support, such as health insurance reimbursement for environmental interventions, to maintain an indoor environment free of asthma triggers.