**2. Research methods**

After having developed the HE app in a semi-controlled manner [11], the next step of development needed to incorporate experiences from its use in the clinical practice. Therefore, we undertook a single case study [17] focused on the HE app as a digitized tool for data collection in occupational therapy. Thus, the purpose of the study was to understand the social and technical issues associated with using the mobile app for data collection. The outcomes were expected to provide an understanding of the realistic use of the HE app and generate input for an evaluation and a final design iteration of the app. For example, there was a need to learn how and to whom the occupational therapist needed to export the data in an actual work situation. Consequently, the export functionality and the design of the final app were not yet fully developed. As such, the HE app was still a prototype during the study.

We contacted municipalities in Denmark to find occupational therapists working with accessibility and home modifications who would be interested in testing the HE app in their daily work. A convenience sample of seven occupational therapists from four municipalities was recruited for data collection. All of those participants worked with accessibility and home modification on a regular basis

and had been doing so for at least six months. Furthermore, as familiarity with HE was key, all participants agreed to complete a Housing Enabler course before testing the HE app. The course was necessary to ensure that the participants could use the tool to carry out valid and reliable assessments, especially given the tool's complexity [16]. After completing the HE courses, the seven occupational therapists each completed five HE assessments using the HE app. Data collection took place for four months.
