Strengths and limitations
The study was designed without an ordinary control group. All participants were provided with an activity tracker and PAI, and home-based online training and online social support were additional interventions in two groups. The design of this study might have limited the potential effect of these interventions compared to PAI. A mixed-method approach is an advantage as the study was based on both quantitative data from a larger population as well as qualitative data from a selected group of users. Although the information gained from the scores on acceptability, adoption and sustained use, the in-depth experiences reported from the qualitative interviews allowed to further examine why and how participants perceived the different digital interventions. The framework approach to qualitative analysis was chosen as it is a flexible tool that can be adapted for use in multidisciplinary research teams and within research projects using a mixed-method design (