Health Literacy-Based Heart Failure Self-care (H2Lit) Application: Development and Usability Testing

The purpose of this study was to describe the development of a health literacy-focused heart failure self-care intervention (H2Lit Web-based app) and assess its usability using an online testing platform. We used an iterative approach, wherein participants evaluated more refined versions of H2Lit over four rounds of testing. Healthy participants were recruited for the earlier rounds of testing, and participants with heart failure were recruited for the final round. A total of 44 participants (10 participants with heart failure) were enrolled in the study. The participants had a mean age of 47.6 years, 57% were female, 70% identified as White, 70% were college-educated, and 34% had low health literacy. Using the System Usability Scale (score range of 0 to 100), the participants gave H2Lit a mean usability score of 74.1 in round 1, 54.3 in round 2, 85.3 in round 3, and 82.5 in round 4. H2Lit's usability score did not significantly differ between participants with adequate health literacy and those with low health literacy after controlling for age, sex, education level, and computer use duration. Further research is needed to determine the effect of the H2Lit intervention on heart failure self-care and heart failure-related outcomes.