OBJECTIVES: To compare condition-related prescription medication utilization across Affordable Care Act Exchange metal levels of health insurance plans for covered individuals with diabetes, chronic obstructive pulmonary disease (COPD) and asthma.

METHODS: A retrospective cohort study was conducted using claims data from three New Mexico Exchange insurers for years 2015-2019. Annually, adults were included if enrolled in Bronze, Silver or Gold plans for ≥11 months and during the year had >1 diagnosis for diabetes, COPD or asthma and >1 condition-related prescription claim. Prescription medication utilization by condition and drug group (based on United States Pharmacopeia classifications) as percentage of condition-related prescriptions, was compared across metal level plans for the 5-year period. Frequencies, percentages with 95% confidence intervals (95% CI) were compared using Rao-Scott Chi-Square tests.

RESULTS: Included members numbered 4888 with diabetes, 801 with COPD, and 2456 with asthma. Significant differences were observed (diabetes p<0.0001, COPD p=0.02, asthma p<0.001). Diabetes prescriptions were highest for metformin, with Bronze use highest (95% CI): Bronze|Silver|Gold=50.3-55.6%|47.0-49.5%|43.8-47.4%, insulin use was similar (Bronze|Silver|Gold=15.3-20.7%|17.2-19.9%|17.6-21.2%), and other antidiabetic agent use lowest for Bronze (Bronze|Silver|Gold=25.6-30.8%|30.2-32.8%|30.6-34.2%). For COPD, short-acting inhaler use (Bronze|Silver|Gold=46.4-65.5%|44.0-51.3%|39.1-46.8%) and long-acting inhaler use (Bronze|Silver|Gold=29.0-48.5%|38.7-46.2%|38.2-49.0%) was similar, while anti-inflammatory/inhaled-corticosteroid use was lowest for Bronze, highest for Gold (Bronze|Silver|Gold=2.4-8.2%|7.7-12.0%|9.1-17.8%). For asthma, antileukotriene use (Bronze|Silver|Gold=21.4-29.7%|28.0-32.7%|25.9-31.4%) and anti-inflammatory/inhaled-corticosteroid use (Bronze|Silver|Gold=8.3-13.7%|9.8-12.8%|10.2-13.7%) was similar, while long-acting inhaler use was lower for Bronze than for Gold (Bronze|Silver|Gold=13.2-21.2%|21.0-24.9%|22.5-27.5%), with shorting-acting inhaler use highest for Bronze (Bronze|Silver|Gold=41.6-50.9%|33.4-37.5%|32.0-36.8%).

CONCLUSIONS: We found significant difference in condition-related prescription claims between members with differing health insurance coverage levels. In general, medications associated with greater severity of disease were a larger percentage in the Gold level, suggesting that individuals may be choosing appropriate levels of insurance for their needs. However, longitudinal studies are needed to further investigate the effect of differing health insurance on appropriate medication utilization for chronic conditions.