A scoping review of disease-modifying antirheumatic drug nonadherence in rheumatoid arthritis: Measurement, prevalence and implications for clinical practice.

AIMS: Adherence to disease-modifying antirheumatic drugs (DMARDs) has been associated with improved treatment outcomes, but how adherence is reported ranges between studies. We therefore aimed to determine how nonadherence to DMARDs used to treat rheumatoid arthritis (RA) has been measured and to report the nonadherence rate with each measure identified. Additionally, we aimed to explore what factors are associated with nonadherence.

METHODS

A scoping review was conducted in the following databases: Embase, Medline, Scopus and Cochrane, searching from 2000 up to 31 August 2022 using search terms related to 'adherence'; 'measures'; rheumatoid arthritis'; and 'medication'. Descriptive analyses were used to analyse and interpret the data according to the stated aims. We included 172 manuscripts that met the inclusion criteria and the median number of participants for each study was 249 (interquartile range 120-767). Measures of adherence included dispensing data, tablet counts, self-report and physician estimates, electronic monitors, questionnaires and blood assays.

RESULTS

Nonadherence was most commonly reported as a proportion and ranged from 1.5 to 100% for any DMARDs as a class, 0 to 95% for conventional synthetic DMARDs and 3 to 95% for biologic DMARDs. Increased disease activity, younger age and comorbidities were found in several studies to be associated with nonadherence, while there were inconsistent findings for sex, education, disease duration and other patient characteristics.

CONCLUSION

Much variability exists in the reported prevalence of nonadherence in RA, in what measures are used to assess nonadherence, how nonadherence is reported and which patient characteristics are associated with nonadherence.