Currently submitted to: JMIR Human Factors
Date Submitted: Mar 24, 2026
Open Peer Review Period: Mar 26, 2026 - May 21, 2026
(currently open for review)
Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Digital Health Intervention to optimize Heart Failure care in a low-resource setting: Design Process and Implementation Strategies
ABSTRACT
Background:
Heart failure (HF) is a leading cause of hospitalizations, particularly in low- and middle-income countries (LMICs). Guideline-directed medical therapy (GDMT) can reduce adverse events by 64%, yet remains underutilized. Digital health interventions (DHIs) may improve GDMT use by enhancing access to care and patient self-efficacy, but their effectiveness depends on sustained patient engagement.
Objective:
To describe the development of a culturally-adapted DHI to support GDMT optimization within Brazil’s public health system (OPT-HF), using human-centered design (HCD) and reciprocal innovation principles.
Methods:
OPT-HF was developed through structured meetings with researchers and health professionals and HCD sessions with patients and caregivers, following the iDesign framework. A three-week mixed-methods pilot study assessed usability and acceptability (primary outcomes), and engagement, self-care behavior (European Self-Care Behavior Scale), and medication optimization (secondary outcomes). An Implementation Research Logic Model (IRLM) was created to define implementation determinants, strategies, mechanisms, and expected outcomes.
Results:
The OPT-HF intervention comprises a multicomponent mobile application featuring telemonitoring of vital signs, educational content, and GDMT tracking, integrated with a dashboard and teleconsultation program. Ten patients were enrolled [mean age 57 years, 40% female] in the pilot study. The intervention demonstrated high usability and acceptability. Engagement was high for daily monitoring tasks but lower for educational videos. Self-care scores improved from 41 to 73, exceeding adequacy thresholds, and 7 of 10 participants showed significant improvement in the medication optimization score. Qualitative analyses highlighted increased perceptions of safety and support, alongside barriers related to Bluetooth connectivity and access to videos and chat functions. These findings informed iterative refinements and IRLM development.
Conclusions:
The OPT-HF DHI showed good usability, acceptability, and preliminary effectiveness in improving HF self-care and GDMT optimization. Culturally tailored, HCD design was essential to enhance engagement. The IRLM supported the understanding of mechanisms underlying this multicomponent intervention and will inform future implementation. Clinical Trial: https://ensaiosclinicos.gov.br/rg/RBR-10vpf9bm
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