THU0083 ROLE OF CLINICAL IMPACT, DISEASE-SPECIFIC KNOWLEDGE AND BELIEFS ABOUT MEDICATION ON THERAPEUTIC ADHERENCE IN RHEUMATOID ARTHRITIS: AN INTEGRATIVE STRUCTURAL EQUATION MODELING APPROACH
Authors: George Karpouzas, Elizabeth Hernandez, Vibeke Strand, Sarah Ormseth
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Treatment of rheumatoid arthritis (RA) to remission is the optimal way to ensure control of symptoms, prevention of structural damage, optimization of function and quality of life. Adherence to medical treatment is, therefore, an integral part of a comprehensive and successful management of RA. <h3>Objectives</h3> We interrogated the influence of three distinct domains of RA clinical impact (disease activity, functional limitations, mood disturbance), patient specific knowledge about RA and beliefs about medications on treatment adherence. <h3>Methods</h3> We evaluated 285 patients with established RA from a single center. In the proposed model, disease activity DAS28(CRP), mood disturbance (Patient Health Questionnaire-9 depression scale and SF-36 Mental Health domain), functional limitations (Health Assessment Questionnaire Disability Index and SF-36 Physical Function domain) and RA-specific knowledge (Patient Knowledge Questionnaire) were expected to predict beliefs about the necessity of RA medications and concerns about them (Beliefs about Medicines Questionnaire) which, in turn, would impact adherence (Simplified Medication Adherence Questionnaire). Cross-sectional multi-group structural equation modeling evaluated the model separately in patients treated with bDMARDs and those only receiving csDMARDs. <h3>Results</h3> RA-specific knowledge was not significantly associated with medication beliefs or adherence and therefore was dropped from the model. Modification indices suggested addition of two supplementary paths (dashed lines) that significantly improved the proposed model fit for both treatment groups, shown in Figure 1. Disease activity, functional limitations and mood disturbance influenced adherence via multiple and often competing pathways, directly or indirectly through a necessity/concerns evaluation by the patient. Notably, RA activity directly promoted adherence in patients on bDMARDs (p&lt;0.01). In contrast, in patients on csDMARDs, RA activity had an indirect, net negative effect on adherence (p&lt;0.01); the main pathway was through worsening mood disturbance which in turn attenuated adherence (p&lt;0.01). This may imply that the experience of disease activity in patients requiring bDMARDs may be sufficiently impactful to independently promote medication adherence. In contrast, disease activity may be largely experienced as depressed mood in patients on csDMARDs which may in turn overwhelm their capacity to adhere. Additionally, mood disturbance adversely influenced adherence directly in patients on csDMARDs (p&lt;0.01) yet there was no significant direct or net indirect effect of mood disturbance on adherence to biologics. Functional limitations fostered adherence through enhanced awareness of medication necessity (p&lt;0.05). <h3>Conclusion</h3> Distinct domains of the impact of clinical RA influence treatment adherence directly or indirectly through a necessity/concerns framework. Mood disturbance and concerns about medications may represent complementary yet salient intervention targets of comprehensive RA management promoting medication adherence; the former may be more relevant for patients on csDMARDs whereas the latter may be more significant with bDMARDs. <h3>Disclosure of Interests</h3> George Karpouzas Grant/research support from: Pfizer, Consultant for: Sanofi-Genzyme-Regeneron, Janssen, Roche-Genentech, Pfizer, Speakers bureau: BMS, Sanofi-Genzyme-Regeneron, Janssen, Roche-Genentech, Elizabeth Hernandez: None declared, Vibeke Strand Consultant for: AbbVie, Amgen, Bayer, BMS, Boehringer Ingelheim, Celgene, Celltrion, CORRONA, Crescendo, EMD Serono, Genentech/Roche, GSK, Horizon, Inmedix, Janssen, Kezar, Lilly, Merck, Novartis, Pfizer, Regeneron, Samsung, Sandoz, Sanofi, Servier, UCB., Sarah Ormseth: None declared