Background Adherence to disease-modifying anti-rheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA) is suboptimal and ranges from 22% to 107%. As non-adherence can result in more disease activity and a lower quality of life, interventions to improve adherence are warranted. Beliefs about medication might be useful intervention targets as they are associated with non-adherence according to existing research.
Objectives This is the first cross-sectional study which aims to examine associations between beliefs about medication and non-adherence in RA patients, taking potential psychological confounders into account in the data-analysis.
Methods Eligible patients (diagnosed with RA for ≥ one year, ≥18 years, using ≥ one DMARD) were included by their rheumatologist during regular outpatient visits between September 2009 and September 2010. Included patients received questionnaires. The Beliefs about Medicines Questionnaire (BMQ) was used to measure the perceived need to take medication (necessity beliefs), the concerns about taking medication (concern beliefs), general medication beliefs, and attitudes towards taking medication. Medication non-adherence (no/yes) was measured using the Compliance Questionnaire Rheumatology (CQR). Associations between beliefs and non-adherence, and the influence of demographical, clinical and psychological factors (symptoms of anxiety/depression, illness cognitions, self-efficacy) were assessed using logistic regression.
Results 580 of the 820 eligible patients willing to participate were included in the analyses (68% female; mean age 63 years; 30% non-adherent to their medication). Weaker necessity beliefs (OR: 0.8, 95% CI: 0.8-0.9) and an unfavorable balance between necessity and concern beliefs (OR: 0.9, 95% CI: 0.9-1.0) were associated with CQR non-adherence. Also, having an indifferent attitude towards medication (no/yes) was associated with CQR non-adherence (OR: 5.3, 95% CI: 1.1-25.8), but the prevalence of patients with an indifferent attitude towards medication was low. The associations were barely confounded by demographical, clinical and psychological factors.
Conclusions (Weaker) necessity beliefs about medication, a more unfavorable balance between necessity and concern beliefs about medication, and having an indifferent attitude towards medication are associated with medication non-adherence. Psychological factors hardly confound those associations. Of the BMQ constructs associated with non-adherence, increasing necessity beliefs about medication in clinical practice might be most worthwhile to improve medication adherence in RA patients.
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Van den Bemt BJF, Van den Hoogen FH, Benraad B, Hekster YA, Van Riel PL, Van Lankveld W (2009). Adherence rates and associations with nonadherence in patients with rheumatoid arthritis using disease modifying antirheumatic drugs. J. Rheumatol. 36:2164-2170.
Acknowledgements We would like to thank Peter Spreeuwenberg for his advice regarding the statistical analyses.
Disclosure of Interest None declared