Contribution of personality traits, psychological factors, and health-related quality of life to medication adherence in patients with rheumatoid arthritis

Purpose: This study sought to investigate the associations between personality traits and medication adherence and to identify predictors of good medication adherence in rheumatoid arthritis (RA) patients. Materials and Methods: A total of 207 RA patients using disease-modifying anti-rheumatic drugs were invited for an interview and questionnaire study. Medication adherence was measured using the Compliance Questionnaire for Rheumatology (CQR). Personality traits were analyzed with the five-factor model of the Korean version of the Big Five Inventory 10. Psychological factors were assessed with the Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and British Columbia Cognitive Inventory. Health-related Quality of Life (HRQoL) and functional disability were evaluated with the EuroQoL-5 dimension questionnaire and Health Assessment Questionnaire. Multivariate logistic regression analyses were performed to investigate predictors of good medication adherence. Results: Nonadherence to medication was reported by 66.7%. The number of daily prescribed pills was higher in the medication adherence group than in the nonadherence group. Concomitant oral glucocorticoid doses were associated with medication adherence. A high level of conscientiousness and diabetes mellitus comorbidity were associated with better medication adherence [odds ratio (OR), 2.11; 95% confidence interval (CI), 1.01–4.38 and OR, 3.00; 95% CI, 1.12–8.07, respectively]. There were no significant differences in psychological factors or HRQoL between medication adherence and nonadherence groups. Conclusion: The personality trait of conscientiousness was associated with medication adherence among the five personality traits evaluated. Patients with diabetes mellitus also showed higher medication adherence than those without this comorbidity.