Relationship between beliefs about medicines, adherence to treatment, and disease activity in patients with rheumatoid arthritis under subcutaneous anti-TNFα therapy

OBJECTIVE: In patients with rheumatoid arthritis (RA), nonadherence to treatment is often related to patients’ beliefs and concerns regarding their medication. This study aimed to analyze the correlations regarding patients’ medication beliefs, medication adherence, and objective measures of disease activity and safety in patients with RA established on subcutaneous (SC) anti-tumor necrosis factor α (TNFα) therapy. METHODS: This Phase IV, noninterventional, non–drug-specific study enrolled patients with RA being treated with stable-dose SC anti-TNFα (adalimumab, etanercept, golimumab, and certolizumab pegol). At initial visit and 6 and 12 months later, patients completed the Beliefs about Medicines Questionnaire-Specific section, assessing perceptions of personal need for anti-TNFα therapy (anti-TNFα-Necessity) and concerns (anti-TNFα-Concerns), Medication Adherence Rating Scale (MARS), mean Disease Activity Score in 28 joints (DAS28), and other scales. Longitudinal data were analyzed by linear mixed models. RESULTS: A total of 460 patients were included. At initial visit, anti-TNFα-Necessity beliefs were high (mean ± SD: 4.3 ± 0.55) vs anti-TNFα-Concerns (2.8 ± 0.78). Medication adherence (MARS) was high (4.8 ± 0.39). All scores remained stable over the 1-year follow-up period. Anti-TNFα-Necessity beliefs and anti-TNFα-Concerns were not related to each other, but strongly correlated with medication adherence. While concerns worsened with disease activity, clinical status, and low quality of life, necessity beliefs remained unaffected. CONCLUSION: In patients with RA established on stable-dose SC anti-TNFα, anti-TNFα-Necessity beliefs persistently outweighed anti-TNFα-Concerns, but both correlated with adherence. These findings may be of use in subsequent studies looking to predict adherence in patients starting treatment with SC anti-TNFα.