Claims data generally lack information on clinical outcomes. However, a validated claims-based algorithm for estimating the effectiveness of biologic agents in treating rheumatoid arthritis (RA) was recently developed and applied to various databases.
The objectives of the study were to implement a claims-based algorithm in a large nationwide database to estimate medication effectiveness and cost for patients with RA using biologic disease-modifying antirheumatic drugs (DMARDs) and to assess the effect of eliminating one criterion from the algorithm on results.
The DMARD groups included patients initiated on etanercept, adalimumab, abatacept, or infliximab. Patients were categorized as effectively treated if they met these six criteria: a medication possession ratio of 80% or greater; no escalation in biologic dose; no switch in biologics; no new nonbiologic DMARD; no new or increased oral glucocorticoid treatment; and no more than one glucocorticoid injection. In a follow-up analysis, the dose-escalation criterion was removed because an increase in dose for infliximab may be appropriate. Average costs for RA-related medications were calculated for each DMARD patient group and divided by the number of patients who met all six effectiveness criteria.
A total of 1196 individuals were included in the analysis. Using the algorithm, the index biologic was categorized as effective for 25.4% of patients overall: 30.3% (102/337) of etanercept, 27.6% (104/377) of adalimumab, 32.7% (37/113) of abatacept, and 16.5% (61/369) of infliximab patients. Total costs for RA medication costs per effectively treated patient ranged from more than $80,000 for infliximab to ~$43,000-$46,000 for the other three groups. Removing the no dose-escalation criterion drastically reduced the cost per effectively treated patient in the infliximab group (to ~$42,000).
Using the original six-criteria claims-based algorithm in a large claims database, infliximab was the least-effective biologic agent and had the highest medication cost per effectively treated patient. However, when a follow-up analysis removed the dose-escalation exclusion criterion, the four groups had similar effectiveness and medication costs per effectively treated patient with RA.