The Effect of Motivational Interviewing on Knowledge, Self-Efficacy, and Treatment Adherence in Patients With Primary Hypertension Living in Semi-Rural Areas: A Randomized Controlled Trial
The Effect of Motivational Interviewing on Knowledge, Self-Efficacy, and Treatment Adherence in Patients With Primary Hypertension Living in Semi-Rural Areas: A Randomized Controlled Trial
This study is a single-center, single-blind, parallel-group randomized controlled trial designed to examine the impact of a Health Belief Model (HBM)-based motivational interviewing (MI) intervention on knowledge level, self-efficacy, and treatment adherence among primary hypertension patients living in a semi-rural region. Hypertension, despite its typically asymptomatic course, is a prevalent chronic condition that contributes significantly to cardiovascular morbidity and mortality. Poor adherence to treatment and insufficient disease-related knowledge remain major barriers to achieving optimal blood pressure control. Self-efficacy is recognized as a crucial psychological determinant influencing lifestyle modification and medication adherence, and theoretical models-particularly the HBM-provide a structured framework for understanding individuals' health perceptions and facilitating behavioral change.
Motivational interviewing, a patient-centered counseling method aimed at strengthening intrinsic motivation, is thought to be particularly effective when combined with the HBM. The integration of these two approaches is expected to enhance individuals' readiness for change and promote active engagement in treatment. Existing evidence indicates that MI-based interventions can improve medication adherence, encourage lifestyle modifications, increase self-efficacy, and support better blood pressure control. These findings form the conceptual basis of the present study.
The trial was conducted between November 2025 and April 2026 at Hisarardı Family Health Center in Simav, Kütahya. The target population consisted of 140 individuals diagnosed with primary hypertension. Using G*Power with an effect size of 0.60, 80% power, and α=0.05, the required sample size was calculated as 50 participants per arm. Stratified randomization by sex and block randomization with blocks of four were employed.
The intervention group received a four-session MI program structured according to the HBM, consisting of the following components:
Enhancing risk perception and awareness of disease severity Highlighting treatment benefits and reducing perceived barriers Strengthening self-efficacy and developing a personalized action plan Strategies for maintaining behavioral change and identifying cues to action Each session lasted 30-45 minutes and was delivered biweekly. Participants in the control group did not receive any educational intervention and continued with routine clinical follow-up only.
Data were collected using the following instruments:
Hypertension Knowledge Level Scale Hill-Bone Medication Adherence Scale Hypertension Self-Efficacy Scale Systolic and diastolic blood pressure measurements Assessments were conducted at baseline (0 month), mid-intervention (3 months), and at the end of follow-up (6 months). Statistical analyses will be performed using SPSS 26.0, including paired and independent sample tests, correlation analyses, and effect size calculations.
Ethics approval, institutional permissions, and scale-use authorizations were obtained prior to data collection, and all procedures were carried out in accordance with the Declaration of Helsinki.
This study is expected to offer valuable insights into the applicability of theory-driven educational interventions in primary care settings, clarify the contribution of motivational interviewing to hypertension management, and inform national initiatives such as the Disease Management Platform (HYP).
Hypertension is a chronic condition characterized by persistently elevated arterial blood pressure. It is clinically defined as a systolic blood pressure of ≥140 mmHg and/or diastolic pressure of ≥90 mmHg. The Turkish Society of Hypertension and Kidney Diseases (THBHD) emphasizes that hypertension often progresses silently without overt symptoms, yet over time it can lead to serious complications such as cardiovascular disease, stroke, renal failure, and other forms of target-organ damage.
Globally, hypertension is among the most prevalent chronic diseases and remains one of the leading contributors to cardiovascular morbidity and mortality. According to the World Health Organization, one in every three adults worldwide is living with hypertension. In Türkiye, the prevalence among adults aged 30-79 years is estimated at approximately 32%. Similarly, Şengül et al. reported a national prevalence of 30.3%.
Long-term hypertension management is closely linked to individuals' capacity to engage in lifestyle modifications, adhere to pharmacological treatment, and effectively self-manage their condition. However, numerous studies indicate that poor adherence to antihypertensive therapy and insufficient disease-related knowledge hinder optimal blood pressure control. These findings underscore the importance of understanding the beliefs and perceptions that shape individuals' health behaviors and developing structured educational models tailored to these determinants.
Self-efficacy, a key psychological construct in behavior change and chronic disease management, refers to an individual's belief in their ability to successfully perform a desired behavior. Evidence suggests that self-efficacy plays a central role in maintaining blood pressure control by enhancing medication adherence, reducing dietary sodium intake, supporting adherence to the DASH diet, promoting regular physical activity, and ensuring consistent blood pressure monitoring. Successful chronic disease management requires more than pharmacotherapy; individuals' disease perceptions, treatment attitudes, and health-related behaviors directly influence clinical outcomes.
Studies on chronic diseases such as hypertension demonstrate that individuals with strong self-efficacy are more committed to medication adherence, regular exercise, dietary adjustments, and self-monitoring behaviors. Accordingly, theoretical models that systematically explain health behaviors serve as valuable tools for guiding behavioral interventions. One such model, the Health Belief Model (HBM), conceptualizes individuals' perceptions of disease risk and the factors influencing engagement in health-promoting behaviors. The model comprises six constructs: perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, and self-efficacy. Structured interventions based on these constructs have been shown to positively influence health behaviors and improve chronic disease outcomes, including in hypertension management.
Motivational interviewing (MI) is a complementary approach that strengthens the effectiveness of HBM-based interventions. MI is a collaborative, patient-centered counseling method that enhances intrinsic motivation for behavior change. Originally developed by Miller and Rollnick (1991) for substance use treatment, it is now widely employed in chronic disease management. MI helps individuals explore personal strengths, resolve ambivalence, and gain ownership of the change process, thereby reinforcing self-efficacy and supporting sustainable health behaviors.
Core principles of MI include demonstrating empathy, encouraging discrepancy between current behaviors and long-term goals, working constructively with resistance rather than confronting it, and enhancing self-efficacy. MI has been especially effective among individuals with low motivation, facilitating adoption and maintenance of health behaviors. In hypertension, MI has been shown to improve medication adherence, dietary compliance, exercise behaviors, and blood pressure monitoring.
When MI is integrated with the Health Belief Model, cognitive constructs such as perceived susceptibility and severity can be strengthened alongside self-efficacy, ultimately enhancing individuals' willingness to initiate and maintain behavioral change.
Primary care represents the foundational level at which preventive, continuous, and person-centered health services are delivered. For chronic conditions such as hypertension, implementing structured interventions that are responsive to individual belief systems and supportive of behavior change is essential. In this context, MI provides a patient-centered communication strategy that promotes treatment adherence, encourages active participation in disease management, and may help reduce the long-term burden on the healthcare system.
Recent studies indicate that MI interventions aligned with the Health Belief Model enhance patient awareness, support hypertension management, improve blood pressure control, strengthen self-efficacy, facilitate lifestyle behavior change, and significantly improve treatment adherence.
The primary aim of the present study is to evaluate the impact of motivational interviewing on knowledge level, self-efficacy, and treatment adherence among individuals diagnosed with primary hypertension living in a semi-rural area.
By integrating MI's motivational strategies with the HBM's focus on health perceptions, the study seeks to address both psychological and behavioral barriers to disease management and offer a theory-driven, practical solution to an important public health problem. It is anticipated that participants will achieve improved disease-related knowledge and awareness, enhanced adherence to treatment, and strengthened self-management abilities. These improvements are expected to promote sustainable lifestyle changes, better blood pressure control, a reduction in complication risk, and an overall improvement in quality of life.
The findings are expected to inform the national Disease Management Platform (HYP), support the feasibility of model-based educational programs in primary care, and contribute to evidence-based patient education practices that strengthen chronic disease management.
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