This study examined total healthcare costs and rates of patients with rheumatoid arthritis (RA) who switch biologic disease-modifying anti-rheumatic drug (bDMARD) therapy in a real world setting.
A retrospective longitudinal analysis was conducted in patients with RA using IMS PharMetrics Plus database from 1/1/2004 to 3/31/2010. The first-line cohort included patients newly initiated on abatacept or the tumor necrosis factor-alpha inhibitors (anti-TNFs) adalimumab, etanercept, or infliximab, with 12 months of continuous follow-up. The second-line cohort included patients initiating a bDMARD with evidence of a different bDMARD within the previous 2 years and with 12 months of continuous follow-up. Switching was defined as a different bDMARD claim within a 200% gap in days supply from the previous bDMARD claim. Non-switchers stayed on their bDMARD in the follow-up period. Monthly total healthcare costs for switchers and non-switchers and rates of bDMARD switching were examined. Switch rates for each bDMARD were also compared.
First-line switchers had significantly higher monthly total healthcare costs after the switch than non-switchers ($3759 vs $2343; p < 0.05), as did second-line switchers ($3956 vs $2616; p < 0.05). First-line abatacept (2.1%) had significantly lower rates of switching compared to adalimumab (9.5%), etanercept (9.0%), and infliximab (5.5%). Second-line abatacept (8.0%) had significantly lower rates of switching compared to adalimumab (16.7%), etanercept (14.4%), and infliximab (14.3%).
There are no clinical data available in this database and, therefore, this study did not examine the clinical drivers of healthcare costs and switch rates.
Monthly total healthcare costs were higher for bDMARD switchers following the switch compared to non-switchers. Patients on abatacept switched less frequently than patients on anti-TNFs. This study highlights the need to identify patients who are likely to switch in order to ensure they receive the appropriate therapy which may improve outcomes and decrease healthcare costs.