RESUMEN
OBJECTIVE: To integrate existing literature on barriers and facilitators to implementing interventions for Medically Unexplained Symptoms (MUS) in primary and secondary care. METHOD: Systematic review following PRISMA guidelines. A search of PsychINFO/Pubmed/Web of Science was performed to select studies focusing on MUS-interventions and implementation. All included papers were checked for quality and bias. A narrative synthesis approach was used to describe the included papers by implementation level, ranging from the specific intervention to the broader economic/political context. RESULTS: 20 (quantitative/qualitative/mixed design) papers were included, but the quantitative studies especially, lacked methodological quality, with possible publication bias as a result. Results showed that the intervention needs to be acceptable and in line with daily practice routines. The professional's attitude and skills are important for implementation success, as well as for overcoming problems in the professional-patient interaction. If patients stick to finding a somatic cause, this hampers implementation. A lack of time is a frequently mentioned barrier at the organizational level. Barriers/facilitators at the social context level and at the economic/political level were barely reported on in the included papers. CONCLUSION: Results were integrated into an existing implementation model, as an example of how MUS-interventions can be successfully implemented in practice.