Inconsistent anticoagulation therapy in AF patients is associated with a higher risk of stroke and abnormal bleeding. The purpose of the study is to investigate the efficacy of a health belief model based self-management of oral anticoagulant therapy intervention on the outcome of medication adherence and the mediators of knowledge, professional support, health belief, and self-efficacy in patients treated with oral anticoagulants for atrial fibrillation. A randomized clinical trial with repeated measurements was conducted. A convenient sample of 110 adults who were treated with anticoagulants for atrial fibrillation was recruited from two teaching hospitals in northern Taiwan. Participants were randomly assigned 1:1 to either the control group (n = 36) or the intervention group (n = 36) after completion of baseline questionnaires. Patients in the experimental group received the health belief model based anticoagulation adherence intervention, including one 60-minute individual instructions and six 15-minute telephone follow-ups. Participants in the control group received regular medication education, 10-minute individual instruction for health knowledge and six follow-up telephone calls for concerning health. Patients in both groups answered the study questionnaires at three and six months. The generalized estimating equations were used to analyze the efficacy of the intervention for enhancing knowledge, knowledge, perceived benefits, perceived barriers, self-efficacy, and adherence to anticoagulant therapies in patients treated with oral anticoagulants for atrial fibrillation. The results of the study will contribute to the knowledge for improving adherence to oral anticoagulation therapies in patients with atrial fibrillation.
BACKGROUND: Inconsistent anticoagulation therapy in AF patients is associated with a higher risk of stroke and abnormal bleeding. However, control of oral anticoagulation therapy in AF patients has been frequently reported as inadequate. Few theoretical based interventions have been tested for enhancing medication adherence in this population. Previous studies showed that the health belief model may offer some advantage over other behavior change theories for enhancing medication adherence in adult with chronic conditions. PURPOSE: The purpose of the study is to investigate the efficacy of a health belief model based self-management of oral anticoagulant therapy intervention on the outcome of medication adherence and the mediators of knowledge, professional support, health belief, and self-efficacy in patients treated with oral anticoagulants for atrial fibrillation. METHODS: The study is a randomized clinical trial with repeated measurements. A convenient sample of 72 adults who were treated with anticoagulants for atrial fibrillation was recruited from two teaching hospitals in northern Taiwan. Participants were randomly assigned 1:1 to either the control group (n = 36) or the intervention group (n = 36) after completion of baseline questionnaires. Allocation was balanced by site by using a minimization method. The health belief model based self-management intervention comprised two main components: a 60-minute individual face to face instruction and six follow-up telephone calls. Participants in the control group received regular medication education, 10-minute individual instruction for health knowledge and six follow-up telephone calls for concerning health. Data were collected at baseline, third month, and sixth month in both groups, by using self-administered questionnaires. The investigator administered the study questionnaire after obtaining informed consent from each subject. The data collection took place at the waiting areas outside the outpatient clinics during the patients' visits to the clinics. For subjects who were unable to read the questionnaire due to vision or other problems, the investigator read each question to help them complete the questionnaire. The instruments include the Atrial Fibrillation Knowledge Scale, Satisfaction Scale about Service and Warfarin Treatment, Belief About Anticoagulation Survey, and Self-Efficacy for Appropriate Medication Use Scale. DATA ANALYSIS: Data were analyzed using the Statistical Package for Social Sciences 20.0 (SPSS, Inc., Chicago, IL, USA). Descriptive analyses were used to describe study variables. Independent t-tests and one-way analysis of variance (ANOVA) were performed to analyze the baseline equivalent between study groups. The generalized estimating equations were used to analyze the efficacy of the intervention for enhancing knowledge, knowledge, perceived benefits, perceived barriers, self-efficacy, and adherence to anticoagulant therapies in patients treated with oral anticoagulants for atrial fibrillation.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
DOUBLE
Enrollment
72
The health belief model based medication adherence intervention comprised two main components: a 60-minute individual face to face instruction and six follow-up telephone calls.
Taipei Medical University Shuang Ho Hospital
Taipei County, Taipei, Taiwan
Taipei Medical University WanFang Hospital
Taipei, Taiwan
The Short-form Adherence to Refills and Medications Scale (ARMS)
There are seven items in the scale. Subjects were asked to indicate how often they actually miss taking their anticoagulants in each item on a 4-point Likert scale (1\_ none of the time to 4\_ all of the time). The total score of the 7 items represents the scale score, with a possible range of 7 to 28. A higher score indicates worse adherence to anticoagulation treatment.
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups.
The Knowledge of Warfarin Anticoagulation Treatment Scale
The 11-item scale covers four areas of warfarin treatment knowledge: administration (e.g., dose, color, and route of administration), interaction with foods, interaction with other drugs, and side effects. There are five choices for each item, and only one of the choices is correct (scored 1). The total score of the 11 items represents the scale score, with a possible range of 0 to 11. Higher scores indicate higher levels of understanding of warfarin treatment. The scale was also modified to measure the NOACs treatment knowledge. To facilitate analysis and comparison, the score of each scale was converted to a scale of 0 to 100 (actual score/possible maximum score x 100).
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups.
The Perceived Benefits Subscale of the Beliefs About Anticoagulation Survey (BAAS)
The subscale covers 5 potential benefits of taking anticoagulation, including lessening the risk of having a stroke, lowering the chance of being hospitalized, feeling healthier, improving quality of life, and worrying less about the disease. For each item, the subjects indicated their levels of agreement on a 5-point Likert scale (from 1\_ strongly disagree to 5\_ strongly agree). The potential scores range from 5 to 25 points, with higher scores indicating higher levels of perceived benefits associated with taking anticoagulation.
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups.
The Concerns About Anticoagulation Therapy Scale
The scale lists ten potential concerns, including drug interactions, forgetting to take anticoagulants, side effects, hospital visits, diet interactions, activity restrictions, impact on work, not helpful, and difficulty of following instructions. The subjects were asked to indicate all concerns that apply to them. Each concern was scored 1. The potential scores range from 0 to 10, with higher scores indicating more concerns.
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups.
The Self-efficacy for Appropriate Medication Use Scale (SEAMS)
The 13-item scale covers two dimensions of self-efficacy: for taking medications under difficult circumstances and for taking medications under uncertain or changing circumstances. For each item, the subjects indicated their level of confidence about taking medications correctly under a specific circumstance on a three-point response scale (1 \_ not confident, 2 \_ somewhat confident, and 3 \_ very confident). The potential scores range from 13 to 39, with high scores indicating higher levels of self-efficacy for appropriate anticoagulant use.
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups.
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