Purpose: To conduct a systematic review of existing methods to evaluate the individual aspects of welfare technology from the perspectives of independence, safety, activity, and participation. Furthermore, the study aimed to describe outcomes that have been the focus of previous research to evaluate individual aspects of welfare technology in older persons living in ordinary housing. Materials and methods: A systematic literature review in PubMed, CINAHL Plus, PsycINFO, Scopus, and Web of Science. Studies selected were those that explored the use of assistive and welfare technology devices from older persons’ perspectives, and which considered the concepts of independence, safety, activity and participation, and quality of life. Results: A broad spectrum of instruments was applied in the studies. For independence, three questionnaires were used in the identified studies. For safety, one instrument was used in two versions. To study activity and participation as well as quality of life, several scales were used. Additionally, several studies included qualitative approaches for evaluation, such as interviews, or posed one or more questions regarding the effects of welfare technology. Conclusions: The integration of digital assistive and welfare technology should be based on the needs of older persons, and those needs must be assessed using reliable and relevant instruments. The heterogeneity of the target group, i.e., older persons, together with the fact that assessments must give consideration to identifying goals, obstacles, and risks as well as users’ preferences, implies a person-centred approach.