AUTHOR=Harkko Jaakko 
  
TITLE=Legitimacy, embedding, and learning framework: lessons from individual placement and support for analyzing sustainment and scale-up of complex psychosocial interventions
  
JOURNAL=International Journal of Public Health
  
VOLUME=Volume 71 - 2026
  
YEAR=2026
  
URL=https://www.ssph-journal.org/journals/international-journal-of-public-health/articles/10.3389/ijph.2026.1609505
  
DOI=10.3389/ijph.2026.1609505
  
ISSN=1661-8564
  
ABSTRACT=ObjectivesTo develop a framework of policy-level domains for analyzing the sustainment and scale-up of Individual Placement and Support and, tentatively, other complex evidence-based psychosocial interventions.MethodsIntegrative review of 41 empirical studies on contextual determinants of Individual Placement and Support (IPS) sustainment and scale-up was conducted. The results were synthesized inductively and interpreted abductively using implementation science, policy implementation research, and welfare policy literature.ResultsThe LEL framework organizes recurring external-context patterns into three policy-level domains: Policy Legitimacy addresses policy legitimization and decision chains linking high-level policy decisions to implementation; Policy Embedding addresses multi-level and cross-sector implementation structure; and Policy Learning addresses implementation evidence infrastructure through which implementation experience informs practice, policy, and model refinement.ConclusionThe Legitimacy–Embedding–Learning (LEL) framework proposes policy-level domains for analyzing IPS sustainment and scale-up. It functions as an integrative analytical framework that supports cumulative evidence-building and comparative research within IPS, with testable relevance for other evidence-based complex psychosocial interventions.