Comparison of Specialty Medication Use for Common Chronic Inflammatory Diseases Among Health Exchange and Other Commercially Insured Members

BACKGROUND: The Affordable Care Act of 2010 allows the purchase of health insurance through special marketplaces called “health exchanges.” The majority of individuals enrolling in the exchanges were previously uninsured, older, and sicker than other commercially insured members. Early evidence also suggests that exchange plan members use more costly specialty drugs compared with other commercially insured members. OBJECTIVES: To (a) examine patient characteristics and specialty drug use for common chronic inflammatory diseases (CIDs) among exchange plan members compared with other commercially insured members and (b) explore variations in specialty drug use within exchange plans by metal tiers (bronze, silver, gold, and platinum), as well as across local markets. METHODS: This analysis included adults aged ≥ 18 years who were enrolled in exchange plans (exchange population) and other commercial health plans (nonexchange population). The primary outcome was the likelihood of using specialty drugs prescribed to treat common CIDs, such as rheumatoid arthritis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis, psoriatic arthritis, and psoriasis. The adjusted likelihood of using CID specialty drugs was calculated from logistic regression controlling for prevalence of CIDs and other health risk factors. RESULTS: A total of 931,384 exchange plan members and 2,682,855 nonexchange plan members were included in the analysis. Compared with the nonexchange population, the exchange population was older, more likely to be female, had more comorbid conditions, but filled fewer prescriptions. The 2 groups were similar in terms of CID prevalence. The observed likelihood of CID specialty drug use was 20.0% lower in the exchange versus the nonexchange populations (341 users per 100,000 exchange members vs. 427 users per 100,000 nonexchange members; P < 0.001). Within the exchange population, the observed likelihood of CID specialty drug use was 132 per 100,000 bronze plan members (69.1% lower than nonexchange); 326 per 100,000 silver plan members (23.5% lower than nonexchange); 579 per 100,000 gold plan members (35.6% higher than nonexchange); and 672 per 100,000 platinum plan members (57.5% higher than nonexchange). All differences were statistically significant at P < 0.001. There were also large differences by local market, ranging from 49.1% lower to 75.8% higher CID use in the exchange population than in the nonexchange population. After adjustment, the exchange population was 16.6% less likely to use CID specialty drugs than the nonexchange population (P < 0.001). Large variation in specialty drug use within the exchange plan metal tiers was reduced. After adjustment, the higher use of CID specialty drugs among the exchange population in certain local plans was no longer statistically significant. CONCLUSIONS: Members insured through exchange plans were older and sicker than those with nonexchange plans, but they did not use more CID specialty drugs compared with the nonexchange population. Large variations were seen among the exchange plan metal tiers and by local markets, which were often related to the risk profiles of exchange plan enrollees.