Changes in asthma claims in a Medicaid population from 1991-1994

Previous reports have found an increase in asthma prevalence and severity during the 1980s. The purpose of this study was to evaluate changes in asthma claims in a cohort of Medicaid enrollees from 1991 through 1994. A historical study used Ohio Medicaid claims data for fiscal years 1989 through 1994. Adult and pediatric enrollees with at least one claim for asthma care during fiscal year 1989 who subsequently were continuously eligible through fiscal year 1994 were divided into 2 cohorts consisting of those with (Cohort 1) or without (Cohort 2) an asthma claim in 1990. Claims were then analyzed forward from 1991-1994. Patients consisted of 3,027 enrollees, including 2,206 children and 821 adults. Overall emergency department visits increased in both cohorts, primarily due to an increase in adult visits. Visits by children who were preschool-aged in 1989 decreased. Patients in the cohort with an asthma visit in both 1989 and 1990 continued to have an increased frequency of emergency department (ED) visits compared to cohort 2. Outpatient visits decreased in both cohorts but the decrease was greater in cohort 1 in spite of the assumption that these patients should have greater attendance at outpatient clinics. The percentage of patients with an outpatient clinic visit within 3 days of their ED visit also decreased. Admissions decreased in both cohorts indicating that there was not a marked increase in asthma severity. Patients in cohort 1 with ED visits in 2 successive years represent those under relatively poorer control. In spite of a continued higher frequency of ED use, these patients had decreased use of outpatient facilities. Severity to the extent reflected by admissions did not increase over this period. Further research may demonstrate that improved outpatient management and followup of higher frequency ED users may lead to greater asthma control.