Estimating prevalence of current asthma and care among Medicaid enrollees by examining final Medicaid paid claims for primary asthma care, when asthma is only reported as a secondary diagnosis, and prevalence of receipt of asthma-related drug claims: CY 2001 and 2003

NCHS publishes childhood asthma prevalence (NHIS) and CDC publishes adult asthma (BRFSS). Prevalence in Medicaid nationally is unknown but is believed to account for a large proportion of the asthma burden on health services. This study aimed to estimate prevalence using the CMS Medicaid eXtract (MAX) research files of enrollment and final paid claims. We identified 2 cohorts and then combined them: a cohort with at least one claim for care with a primary diagnosis of asthma; and, another cohort with asthma only reported as a secondary diagnosis. In 2001, 4.6% (2,292,406) of the 50,078,316 Medicaid population had a primary and/or a secondary diagnosis of asthma (primary =1,597,585; secondary = 694,821. In 2003 prevalence increased to 5.04% (2,906,721) (primary =1,947,938; secondary = 958,783).

In 2001, 70% of of the identified asthmatics received asthma-related care, and 67% in 2003. Among asthmatics, 4% (97,496) were hospitalized for asthma; 68 % (1,570,972) received asthma ambulatory care in 2001. Additional prevalence estimates will compare variations by year for gender, age group, race/ethnicity, and type of care. Overall, race/ethnicity and gender differences persisted throughout the cohorts for both years. Black males, especially children, have higher rates of hospitalizations and ambulatory services; however, caucasians are more apt to have an asthma-related drug claim.

For drugs, findings indicated that in 2001 82% (1,878,550)of asthmatics had at least one asthma-related claim; in 2003 – 76.3%. Among asthmatics who received asthma care in 2001, 58% (1,332,464) had an asthma-related drug claim compared with 56% (1,627,809) in 2003. Further research continues.