Use of asthma medication dispensing patterns to predict risk of adverse health outcomes: a study of Medicaid-insured children in managed care programs.

BACKGROUND: Regular use of inhaled anti-inflammatory (AI) medication improves outcomes for children with persistent asthma.
OBJECTIVE: To relate 3 measures of asthma medication dispensing to physical health and hospital-based events among children with asthma who were enrolled in 1 of 5 managed care health plans.
METHODS: Parents of Medicaid-insured children with asthma were interviewed at baseline and 1-year follow-up. Utilization data were collected from the health plans in which the children were enrolled. Subjects were stratified into 3 subgroups according to asthma severity: intermittent asthma; persistent asthma for which beta-agonist (BA) medication was dispensed infrequently (< or = 3 times per year); and persistent asthma for which BA medication was dispensed frequently (> or = 4 times per year).
RESULTS: Baseline interviews were completed by 1,663 parents (63% response rate), 1,504 of whom were enrolled in their health plan for at least 11 months during the baseline year. Follow-up interviews were completed by 1,287 (86%) of the 1,504 parents. Among the subgroup of children with persistent asthma for whom BA was dispensed frequently, those who had 1 to 3 AI dispensings had a greater risk for hospital-based events than those with 6 or more AI dispensings. Baseline-year AI medication utilization patterns were not associated with follow-up-year outcomes. No clinically meaningful association was found in subgroups with less severe asthma; however, few AI medications were dispensed to these children.
CONCLUSIONS: Policymakers and clinicians who wish to use medication-based measures to evaluate quality of asthma care should consider counting the number of times AI medication is dispensed among children with more severe asthma.