Geographic variation of asthma quality measures within and between health plans

Objective: To contrast health plan performance in treating pediatric asthma within and between different geographic regions. Study Design: Retrospective analysis of administrative claims data for 18 health plans serving Medicaid enrollees. Methods: The study population was 3970 children 5-18 years old with persistent asthma who were continuously enrolled in the same Michigan Medicaid health plan for 2002 and 2003, with no other source of health insurance. Outcome measures were assessed based on national guidelines for asthma management: at least 1 asthma controller medication prescription, at least 1 outpatient visit, 1 or more asthma emergency department visits, and an annual influenza vaccination. Results: Adherence to national guidelines varied significantly (P ≤ .05) between plans. The proportion of children with at least 1 asthma controller prescription ranged from 66% to 88%; the proportion of children with influenza vaccination ranged from 3% to 46%. Plan ranking varied depending on the guideline measure used. The plan with the lowest aggregate proportion of children who had asthma controller prescriptions (66%) had regional proportions that ranged widely, from 44% to 72%. Some plans were observed to rank highly in performance in 1 region and substantially lower in other regions; similar with-plan regional variation was found for each outcome measure. Conclusions: Assessments of adherence to Medicaid pediatric asthma management guidelines at the plan level may be insufficient to identify opportunities for improvement. Administrative claims-based profiles of plan performance that are sensitive to regional variations in plan characteristics may be particularly useful in isolating and prioritizing quality-improvement opportunities.