Methods for measuring adherence to oral disease-modifying drugs in rheumatoid arthritis and factors associated with low adherence to pharmacological treatment

Objectives: To review the definitions, associated factors, as well as the methods for the measurement and determination of adherence to oral disease modifying drugs in rheumatoid arthritis. Methods: A search of the literature was carried out in the PUBMED databases up to December 2017 using MeSH terms: (((“Arthritis, Rheumatoid” [Mesh] AND “Medication Adherence” [Mesh]) OR “Patient Compliance” [Mesh]) AND “Antirheumatic Agents” [Mesh]). Only articles that included an adult population and were in Spanish or English were reviewed. Results: From the 387 articles found, 43 were included for general review (definitions of adherence, compliance, concordance and persistence, components, classification and dimensions of adherence, risk factors related to non-adherence, description of direct and indirect methods for measuring adherence). Only 9 articles measured adherence and included information about risk factors related to non-adherence to oral treatment in rheumatoid arthritis. Conclusions: The adherence to pharmacological treatment in rheumatoid arthritis is sub-optimal and is associated with less effectiveness in the control of inflammatory activity. The main factors related to low adherence include problems of drug access and availability, increased activity and duration of the disease, polypharmacy, use of medications for prolonged periods, socioeconomic stratum, ethnicity, adverse drug reactions, perception of ineffectiveness of the medication, and concomitant diseases. It is necessary to incorporate the systematic measurement of pharmacological adherence within clinical practice. It is also important to identify the most frequent risk factors associated with low adherence, in order to design strategies aimed at improving patient adherence and achieve better clinical outcomes.