User participation among people in vulnerable situations at service level. A scoping review exploring impact for individual stakeholders and services

User participation is an attempt to democratise and improve health and welfare services. Although central political guidelines emphasise user participation, there is limited knowledge of its impact, especially regarding user participa tion at service level, where the aim is to improve services in general. This knowledge gap applies particularly to groups of users who face difficulties in exercising autonomy. This scoping review aimed to explore the impact of user participation at service level for people in vulnerable situations and how this process affects the involved stakehol ders. From a literature search that yielded 4,964 hits, 22 articles were included in the final review. The finding shows that, at the individual level, user participation could facilitate personal empowerment among the involved users and affect the involved professionals’ knowledge. However, some users also experienced disempowerment due to their involvement in user participation activities. Impacts at the organisational level were that user participation resulted in changes in attitudes, knowledge, culture, professional practice, interventions, an increased number of employees, organisational development and changes in policies. This review also contributes to theoretical development by expanding the knowledge of how the impact of user participation may be perceived, and argues for a circular under standing of impact.