Abstract Background Implementing the evidence-based Individual Placement and Support (IPS) model in welfare states like Sweden faces contextual challenges that often necessitate local adaptations to enhance fit and effectiveness. While fidelity assessments aim to ensure effective outcomes, adaptations may lead to unintended drift from core components. The Model for Adaptation Design and Impact (MADI) help analyse the characteristics of adaptations and their ripple effects. This study explores the interplay between implementation, adaptations and fidelity in mental health services using the MADI framework. Methods An embedded case study design was used, involving five mental health services in a major Swedish city. Data from 26 key informants, field notes, and meeting protocols were analysed using content analysis and interpreted through the MADI framework. Results The adaptations were both planned and unplanned, some adaptations supported the integration of IPS and others negatively impacted core components, revealing unintended impacts on implementation and intervention outcomes. Conclusions To understand adaptations and its pathways when implementing IPS in mental health services, and other stakeholders, the MADI framework is valuable. Excessive adaptations can compromise core values and fidelity assessments must account for adaptations and their consequences. To ensure IPS remains effective, some practices within mental health services and other organisations may need to be revised or adapt to the method itself to support IPS implementation and outcomes. The findings offer valuable insights for professionals and user organisations adopting evidence-based practices in mental health services.
Sturesson et al. (Thu,) studied this question.