Determinants Of Adherence To Postoperative Anticoagulant Therapy Among Patients With Mechanical Heart Valve Replacement:an Application Of The Health Belief Model

Objective:1. To describe the level of adherence to postoperative anticoagulant therapy among patients with mechanical heart valve replacement.2. To explore the determinants of adherence to postoperative anticoagulant therapy among patients with mechanical heart valve replacement based on the Health Belief Model.3. To provide implications in cognitive behavioral interventions among patients with mechanical heart valve replacement.Methods:Using the convenience sampling method, we recruited 113 patients who had mechanical heart valve replacement hospital between January 2012 and December 2014 in two tertiary hospitals in Liaocheng City. Interviews were carried out by face to face or telephone, using self-developed questionnaires on adherence to postoperative anticoagulant therapy, warfarin anticoagulation knowledge, health belief model and sociodemographic and clinical information more than one month after hospital discharge.Results:1.91.2% of patients had high adherence to postoperative anticoagulant therapy. Score indexes for adherence to medication,, review of INR, lifestyle and self-monitoring was 96.1%,91.4%,85.7%, and 58% respectively.2.Anticoagulation knowledge score index averaged 62.7%.41.6% of patients had low scores. Score indexes for perceived severity, susceptibility, behavioral benefits, behavioral barriers and self-efficacy in Health belief constructs were 86.4%,83.9%,83.1%,64.6%, and 92.9% respectively.3. The anticoagulant adherence score did not vary significantly by sociodemographic characteristics (P> 0.05), while it seemed that higher anticoagulant adherence was found among female patients with older age, higher education, higher income, living with their families.4. The anticoagulant adherence score did not vary significantly by clinical characteristics significantly (P> 0.05), while it seemed that higher anticoagulant adherence was found among patients within six months after surgery, with comorbidity, better heart function, taking imports warfarin anticoagulation, and without anticoagulation complications.5. Anticoagulant adherence was positively correlated with anticoagulation knowledge, perceived severity, susceptibility, behavioral benefits, behavioral barriers, and self-efficacy (r= 0.327-0.505, P<0.001).6. Self-efficacy, behavioral barriers, anticoagulation knowledge and educational level were independent predictors of anticoagulation adherence among patients with mechanical heart valve replacement (β= 0.21～-0.37, P<0.05). The rates of explained variance in anticoagulation adherence were 12.5%,9.3%, and 32.6% by socio-demographic and clinical treatment factors, anticoagulant therapy knowledge, health belief model constructs, respectively.Conclusion:1. Patients with mechanical heart valve replacement have moderate or high adherence to postoperative anticoagulant therapy. Adherence to medication is the best, followed by the review of INR and adherence to lifestyle, and adherence to self-monitoring was worst.2. Anticoagulation knowledge is low. Health beliefs were generally moderate or high; self-efficacy is the highest, and the lowest is behavioral barriers.3. Anticoagulation adherence does not differ by socio-demographic and clinical characteristics among patients with mechanical heart valve.4. Anticoagulant adherence has a positive relationship with anticoagulation knowledge and health beliefs constructs.5. Health belief model can well explain anticoagulant adherence behavior in patients with mechanical heart valve replacement. Self-efficacy, behavioral barriers and anticoagulant therapy knowledge and education are significantly independent predictors.