[Practice-based evidence in prevention and health promotion among socially disadvantaged communities].

In recent years numerous health promotion and prevention efforts have been created for socially disadvantaged communities. There is a broad consensus that such measures should be scientifically sound; however, the criteria for evidence-based medicine (EBM) have been shown to have limited applicability in this area. It is widely debated which scientific approaches are most appropriate. Several authors have called for the production of "practice-based evidence"(PBE) as an alternative, focusing on ways to produce evidence based directly on practical experience. Implied is a variety of methodological and epistemological approaches for generating knowledge about the effectiveness of interventions. In contrast to the usual means of generating evidence, PBE suggests that practitioners instead of researchers take on the leading role in the generation and interpretation of intervention data. To date, PBE is an idea in need of further definition, both in terms of theory and practice. On the basis of recent research the authors present a definition for PBE and a model for how it could be generated. The authors propose an "Evidence Cycle" which would synthesize the findings from local evaluations for the purpose of generating practice guidelines (Good Practice Criteria) which can be developed in an ongoing way as new data becomes available. In this way local theories of disease causation and development and local evidence for intervention effectiveness could be drawn together to produce empirically-based, generalizable statements about effective health promotion and prevention for disadvantaged communities.