Improving Medication Adherence in Heart Failure Through Pharmacist-Led Patient Education: Protocol for a Mechanism-Based Study of Information, Motivation, and Behavioral Skills

Abstract

Background: Heart failure (HF) remains a major global health challenge. Guideline-directed medical therapy can effectively reduce mortality and hospitalizations; however, persistent medication nonadherence hinders its real-world impact. Although recent guidelines emphasize the pivotal role of pharmacists in supporting medication adherence, the mechanisms through which pharmacist-led patient education influences medication adherence remain underexplored. Identifying these mechanisms could inform the development of evidence-based strategies to optimize medication adherence and ultimately improve long-term outcomes in HF management.

Objective: This study aims to establish an Information-Motivation-Behavioral Skills (IMB) model to elucidate the mechanisms influencing medication adherence among patients with HF and to compare pre- and postintervention models for identifying significant pathways affected by pharmacist-led patient education.

Methods: In this longitudinal pretest-posttest study, all IMB constructs-information, personal motivation, social motivation, behavioral skills, and behavior-will be assessed using validated patient-reported outcome measures (PROMs) at baseline and three and six months postintervention; additionally, verbal inquiries will be conducted to evaluate the information construct and prescription refill data will be incorporated to supplement the behavior construct. Multigroup structural equation modeling will examine relationships among these constructs and their impact on medication adherence. Latent class growth modeling will also be employed to identify distinct adherence trajectory subgroups after six-month follow-up.

Expected outcomes: The recruitment phase commenced in early May 2025. By evaluating structural changes in IMB pathways pre- and postintervention using PROMs, followed by identifying short-term and sustained responders, the study is expected to facilitate the precise targeting of pharmacist-led interventions to maximize clinical impact. This approach emphasizes the importance of tailoring healthcare delivery to individual medication adherence profiles. It aims to ensure that pharmacist-led patient education achieves its fullest potential in populations expected to benefit the most, particularly patients with HF-a perspective that, to our knowledge, has not been previously explored.

Keywords: heart failure; information–motivation–behavioral skills model; latent class growth modeling; medication adherence; pharmacist-led patient education; structural equation modeling.

Figure 1

Structure of the Information–Motivation–Behavioral Skills (IMB) model. The IMB model illustrates the relationships between information, motivation (personal and social), behavioral skills, and behavior. The model demonstrates how these components influence behavior, with behavioral skills mediating the effects of information and motivation on behavior.

Figure 2

Illustration of the Advanced Patient-centered Pharmacist-Led Education on the Heart Failure (APPLE-HF) management program. The program integrates pharmacist-led individualized counseling, which addresses barriers to medication adherence and suggests lifestyle and supportive measures. Patients are referred by clinicians and co-managed with assigned pharmacists. They receive tailored education informed by the latest HF guidelines. Key components of the APPLE-HF management program include (1) using predefined consolidated medication lists to collaboratively review prescriptions and advance adherence strategies; (2) addressing barriers to adherence through proactive discussions and interactive dashboards with patient-specific visualizations of risks and projected survival curves to identify misconceptions and enhance medication adherence; and (3) guiding lifestyle modifications, including dietary control, fluid management, and exercise. This team-based, patient-centered model aims to improve HF outcomes.

Figure 3

Proposed conceptual framework of the Information–Motivation–Behavioral Skills (IMB) model integrated with selected instruments. Ellipses represent latent variables conceptualized and measured through observed variables, while rectangles represent observed variables directly associated with a single instrument. The latent construct of information is measured using two tools: the Medication Understanding Questionnaire (MUQ) and the Okere–Renier Survey. Personal motivation and behavioral skills are represented as rectangles because each construct is measured using a single instrument—personal motivation via the Beliefs about Medicines Questionnaire–Specific (BMQ-Specific) and behavioral skills via the Self-Efficacy for Appropriate Medication Use Scale (SEAMS). Social motivation is measured using two instruments, the Traditional Chinese version of the modified Patient Satisfaction with Pharmacist Services 2.0 (C-mPSPSQ 2.0) (subscales for quality of care [QOC] and patient–pharmacist relationship [PPR]) and the Medication-Specific Social Support Questionnaire (MSSS). Finally, behavior is represented as an ellipse and assessed using the proportion of days covered (PDC) and the Eight-Item Morisky Medication Adherence Scale (MMAS-8).