An interventional study of The medication adherence intervention in Anticoagulants, sponsored by National Taipei University of Nursing and Health Sciences. Completed at 2 sites in Taiwan. Open to participants aged 20 Years and older. Per ClinicalTrials.gov, last updated 2021-09-22.
Sponsored by National Taipei University of Nursing and Health Sciences · Not applicable, Interventional, and Other
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.
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The medication adherence intervention comprised two main components: a 60-minute individual face to face instruction and six follow-up telephone calls.
Behavioral: The medication adherence intervention
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.
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.
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.
The Satisfaction Scale About Service and Warfarin Treatment (SSWT)
The original scale includes seven positive statements about the services and warfarin treatment. In the current study, the term of warfarin was replaced with anticoagulants. The item 5 (regarding INR monitoring) in the original scale was deleted as it only applies to patients treated with warfarin. Therefore, there were only six items used in the current study. For each item, the subjects indicated their levels of agreement on a 5-point Likert scale (from 0_ strongly disagree to 4_ strongly agree). The total score of the 6 items represents the scale score, with a possible range of 0 to 24. Higher scores indicate higher levels of satisfaction about service and warfarin treatment.
Time frame: baseline (T1), 12th week (T2), and 24th week (T3) follow-ups
| Milestone | The Intervention Group | The Control Group |
|---|---|---|
| Started | 36 | 36 |
| Completed | 33 | 30 |
| Not completed | 3 | 6 |
| Withdrew: Withdrawal by subject | 1 | 1 |
| Withdrew: Medical reason: change anticoagulation drug, hemorrhage, operation | 2 | 5 |
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.
| score on a scale | The Intervention Group | The Control Group |
|---|---|---|
| baseline (T1) | 9.6 ± 1.6 | 9.4 ± 1.7 |
| 12th week (T2) | 8.5 ± 1.7 | 9.3 ± 2.2 |
| 24th week (T3) | 8.1 ± 1.4 | 9.2 ± 2.2 |
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).
| percentage of accuracy | The Intervention Group | The Control Group |
|---|---|---|
| Baseline (T1) | 35.9 ± 15.7 | 36.9 ± 20.0 |
| 12th week (T2) | 63.9 ± 22.5 | 43.7 ± 23.0 |
| 24th week (T3) | 66.4 ± 18.2 | 49.5 ± 21.8 |
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.
| units on a scale | The Intervention Group | The Control Group |
|---|---|---|
| baseline (T1) | 20.2 ± 2.6 | 19.9 ± 2.0 |
| 12th week (T2) | 20.9 ± 2.6 | 19.8 ± 1.3 |
| 24th week (T3) | 21.6 ± 2.6 | 20.3 ± 2.1 |
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.
| score on a scale | The Intervention Group | The Control Group |
|---|---|---|
| baseline (T1) | 1.2 ± 1.4 | 1.8 ± 1.4 |
| 12th week (T2) | 0.8 ± 1.4 | 1.4 ± 1.5 |
| 24th week (T3) | 0.5 ± 1.0 | 1.1 ± 1.2 |
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.
| score on a scale | The Intervention Group | The Control Group |
|---|---|---|
| baseline (T1) | 32.0 ± 6.0 | 31.4 ± 6.4 |
| 12th week (T2) | 33.7 ± 5.2 | 33.1 ± 5.5 |
| 24th week (T3) | 35.3 ± 4.5 | 33.3 ± 4.6 |
The original scale includes seven positive statements about the services and warfarin treatment. In the current study, the term of warfarin was replaced with anticoagulants. The item 5 (regarding INR monitoring) in the original scale was deleted as it only applies to patients treated with warfarin. Therefore, there were only six items used in the current study. For each item, the subjects indicated their levels of agreement on a 5-point Likert scale (from 0_ strongly disagree to 4_ strongly agree). The total score of the 6 items represents the scale score, with a possible range of 0 to 24. Higher scores indicate higher levels of satisfaction about service and warfarin treatment.
| score on a scale | The Intervention Group | The Control Group |
|---|---|---|
| baseline (T1) | 19.7 ± 3.1 | 18.8 ± 2.9 |
| 12th week (T2) | 19.4 ± 2.9 | 18.9 ± 2.6 |
| 24th week (T3) | 20.6 ± 3.0 | 19.7 ± 3.1 |
Collected over 6 months. Non-serious events are listed at a 0% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| The Intervention Group | 0/36 (0%) | 0/36 (0%) | 0/36 (0%) |
| The Control Group | 0/36 (0%) | 0/36 (0%) | 0/36 (0%) |
Age 20 years and over, diagnosed with AFib by physical and receiving anticoagulation therapy
| Age, Categorical(Participants) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| <=18 years | 0 | 0 | 0 |
| Between 18 and 65 years | 14 | 14 | 28 |
| >=65 years | 22 | 22 | 44 |
| Age, Continuous(years) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| Mean | 69.3 ± 7.5 | 73.3 ± 10 | 71.3 ± 9.0 |
| Sex: Female, Male(Participants) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| Female | 12 | 17 | 29 |
| Male | 24 | 19 | 43 |
| Race (NIH/OMB)(Participants) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| American Indian or Alaska Native | 0 | 0 | 0 |
| Asian | 36 | 36 | 72 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 0 |
| Black or African American | 0 | 0 | 0 |
| White | 0 | 0 | 0 |
| More than one race | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 0 | 0 |
| Region of Enrollment(Participants) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| Taiwan | 36 | 36 | 72 |
| Kinds of Anticoagulation(participants) | The Intervention Group | The Control Group | Total |
|---|---|---|---|
| Warfarin | 17 | 17 | 34 |
| NOACs | 19 | 19 | 38 |
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National Taipei University of Nursing and Health Sciences