OBJECTIVES : There is a general lack of empirical studies collecting data on physical activity (PA) levels of patients with haemophilia A. Mobile technologies can offer high potential solutions to increase the rigorousness and reliability of data collected within clinical studies. However, the development process of mobile health (mHealth) apps is often inadequate and not sufficiently participatory, affecting the potential to meet intended purposes. The aim of this study was to design and validate a mHealth application for data collection in the POWER observational study, directed at patients with haemophilia A.

METHODS : We adopted a user-design process grounded in design science, engaging several stakeholders in the development and usability testing of this application. During an initial need-assessment Focus Group (FG) we elicited the specific design requirements of the end-users. We then conducted 2 Exploratory FGs to seek additional inputs for improvement and 2 Confirmatory FGs to validate the proposed artifact and test its usability. All participants involved in the later stages of the design refinement contributed to further improve the app design.

RESULTS : Thematic analysis findings of the need-assessment FG were: recommendations about sense-making, simplification of functionalities, maximized integration, and a limited feeling of control. The end-users considered the app usable and rated it highly: average scores of 5.32 and 6.20 (maximum score 7) in the two iterative usability testing cycles indicated high and growing satisfaction.

CONCLUSIONS : The adoption of a thorough user-centered design process can maximize the likelihood of sustained retention of the POWER mHealth application and make it fit for data collection of relevant outcomes in the observational study. Findings from our work support the use of different types of FGs in the design process of a mHealth application. Continuous use of the application and the actual level of engagement will be properly evaluated during the on-going study.