Measurement and rates of persistence with and adherence to biologics for rheumatoid arthritis: a systematic review

Background: Biologics are an important addition to the conventional care of patients with rheumatoid arthritis (RA). Poor persistence with and adherence to biologics can undermine the effectiveness of these medications. There are no standardized methods to track persistence with and adherence to biologics.

Objective: The goal of this systematic review was to assess the methods of measurement and reported rates of persistence with and adherence to biologic regimens in patients with RA in clinical practice.

Methods: Observational studies that evaluated persistence with and adherence to biologic treatments in patients with RA were identified by searching Medline and SCI-Expanded for observational studies published in English between January 1995 and May 2009, using the following search terms: adalimumab, adherence, arthritis, biologics, compliance, discontinuation, etanercept, infliximab, persistence, RA, treatment retention, and TNF. The articles were independently reviewed to identify relevant studies and abstracted data.

Results: Of the 52 studies identified, 73% were based in Europe and 21% were set in the United States. All but 1 study reported measures of persistence, such as median drug survival and rates of discontinuation and retention. Four studies reported on adherence, all of which were conducted in the United States and used administrative claims data. Methods of persistence and adherence measurement were unclear or, if recorded, varied considerably across studies. Although various continuation rates (persistence) were reported across studies, the overall range of continuation at 12 months was 32.0% to 90.9%. Continuation rates were generally higher with the addition of methotrexate or other disease-modifying antirheumatic drugs.

Conclusion: The data from the available studies on RA treatments suggest a need for better methods for tracking persistence and adherence, for examining prescribing patterns, and for identifying interventions to improve adherence.