Impact Of Warfarin Knowledge And Psychosocial Factors On Warfarin Adherence In Patients With Non-valvalar Atrial Fibrillation

Background:Atrial Fibrillation(AF)is the most common cardiac arrhythmia in clinical settings. The famous Framingham research reported: every four people have one person is in the risk of AF after 40years old in the life, which is higher than that of heart failure (1/5) and female breast cancer (1/8). The most serious complication of AF is thromboembolism, and the incidence of ischemic stroke in non-valvalar atrial fibrillation is about 5%, which is 2 to 7 times of patients without of AF. Ischemic stroke is the major reason of death and disability in AF, and how to prevent ischemic stroke is the important link in the treatment of AF. Five internationally recognized trials had confirmed warfarin could prevent ischemic stroke effectively. The mechanism of AF is not clear, and the treatment strategy of AF includes cardioversion and maintaining sinus rhythm/controlling ventricular rate and anticoagulation. But the status of anticoagulation in AF in China is low ratios,non-standard of treatment and high incidence of ischemic stroke. Hu et al.'s epidemiology investigation on AF in China displayed: the warfarin anticoagulation rate was only 1.7%, more than 97% patients never took warfarin, and nearly 1/4 patients don't monitor INR, or their INR kept in invalid low status(1.3～1.5). The value of INR <2.0 or >3.0, which means the doses of warfarin are inadequate or too much may lead recurrent stroke or VTE due to under-anticoagulation or hemorrhagic events due to over-anticoagulation. Adherence, defined as the extent to which a person's medication taking behavior coincides with medical advice, was found to have substantial impact on anticoagulation control. Previous study on warfarin compliance focused on patients'demographic factors and the clinical characteristics, however, there is lacking of data regarding the impact of psychosocial factors on warfarin adherence.The aim of this study is to investigate the effects of warfarin knowledge and psychosocial factors such as anxiety/depression/social support/self-efficacy on the warfarin adherence in non-valvalar atrial fibrillation (NVAF) patients, and to formulate specific nursing strategies to guide patients' safety and effectively anticoagulation, which will potentially help patients to prevent adverse clinical outcomes.Objective:1. To investigate the level of warfarin compliance in non-valvalar atrial fibrillation patients. 2. To investigate warfarin knowledge level/psychological conditions and to explore the influencing factors of warfarin adherence in patients with non-valvalar atrial fibrillation.Materials and Methods:A total of 210 AF patients were investigated by using a structure questionnaire for general data of patients, such as demographic and clinical factors, self-designed warfarin compliance questionnaire, self-designed warfarin knowledge questionnaire, Zung Self-Rating Anxiety Scale (SAS) and Zung Self-Rating Depression Scale (SDS), the Social Support Rating Scale (SSRS) and Self-Rated Abilities for Health Practices Scale (SRAHP). To analyze the relationship between warfarin compliance and these variables, then to explore the impact factor(s) of warfarin compliance.Results:1. The score of warfarin adherence questionnaire ranged from 16 to 32, the average score of warfarin adherence questionnaire was (23.29±4.09). The"having INR monitored on the requested dates"and"taking stable quantity of vitamin K everyday"were the lowest scored.2. The average score of warfarin knowledge questionnaire was (4.92±2.26), there were 9.52%,8.10% and 4.29% of the patients who know which medications could influence anticoagulation therapy,what kind of food can affect INR level and Vitamin K-contained products; the average score of SAS/SDS were (43.87±8.67) and (44.94±9.94) respectively; the average score of SSRS was (41.90±7.69); the average score of SRAHP was (74.82±1 5.72).3. Warfarin adherence was significantly associated with the level of warfarin knowledge,self-efficacy; and the score of warfarin adherence was positively correlated with social support scores,female and education level; while negatively correlated with SDS scores. Multiple linear regression model pointed that the level of warfarin knowledge,self-efficacy and SDS scores were significant predictors of warfarin adherence.Conclusions:1. The warfarin compliance in NVAF patients was good, but patients'warfarin knowledge was poor and the lacking of knowledge was more obvious with respect to the diet, or drug-drug or drug-supplement interactions. The salient low scored items present the health providers with potential intervention part in the practice.2. The level of warfarin knowledge,self-efficacy and SDS scores were significant predictors of warfarin compliance. It means that health providers could improve patients'warfarin compliance by enhancing patient's warfarin knowledge, improving patients'self-efficacy and alleviating patients'depression.