Feasibility and design of a novel smartphone app to deliver blood pressure-lowering high-resistance inspiratory muscle strength training

Background: High-resistance inspiratory muscle strength training (IMST) is a time-efficient form of respiratory exercise shown to lower blood pressure in midlife and older adults (aged ≥50 years) in randomized controlled trials delivered in clinical research settings. The purpose of this study was to design a feasible and acceptable smartphone application (app) for independently delivering IMST for lowering blood pressure. Methods: Two rounds of iterative focus groups comprised of midlife and older women and men with abovenormal systolic blood pressure (self-reported ≥120 mmHg) were performed to gain feedback on interest in an IMST smartphone app and design features. Focus group results were analyzed using a Consensual Qualitative Research (CQR) coding and data analysis protocol. Clickable wireframes were developed based on focus group findings. The wireframes were then beta tested for usability and additional feedback from target users was obtained. Results: Among midlife and older adults, there was considerable interest in app-delivered IMST as a lifestyle intervention for lowering blood pressure. Potential facilitators and barriers of use for a potential app also were uncovered. Furthermore, the app wireframes were found to be highly usable, indicating that the app is ready for full-scale programming. Conclusions: We have designed a feasible and acceptable smartphone app for independently delivering blood pressure-lowering IMST in midlife and older adults.