Bridging effectiveness and implementation: the GERONTE hybrid approach to evaluating integrated care for older multimorbid patients

Background: The GERONTE Project, funded under the EU Horizon 2020 Programme, seeks to improve outcomes and quality of life for older adults living with multimorbidity and cancer by supporting a shift from disease-specific models toward integrated, person-centered care. The project adopts a hybrid effectiveness–implementation design type 1, which combines a clinical trial and an implementation study: FRONE, a stepped-wedge randomized controlled trial (SW-RCT) in France evaluating the effectiveness of the Geronte Model, and IMPLEMENT, a multi-country observational study conducted in Belgium, France, Ireland, Italy, and the Netherlands. This hybrid design allows for the integration of evidence on clinical effectiveness with contextual and implementation data across diverse healthcare systems, addressing a central question: what approach to data collection, analysis, and synthesis best enables a comprehensive evaluation—economic, process, and implementation—to guide the transition to integrated care?

 

Approach:FRONE and IMPLEMENT together offer complementary insights. The FRONE SW-RCT tests the impact of the Geronte Model on patient outcomes, processes, and costs within the French system, requiring the integration of quantitative and qualitative data within complex, multidisciplinary care environments. The IMPLEMENT study examines 20 hospitals across five countries, mapping oncology care pathways for older multimorbid patients and exploring how contextual factors—organizational structures, professional collaboration, and digital infrastructures—can facilitate or hinder implementation and scalability. Both studies employ mixed-method approaches, combining health economic evaluation, process tracing, and qualitative inquiry with stakeholders such as oncologists, geriatricians, nurses, and data managers.

 

Results: The hybrid design has proven essential to understanding both what works and why it works in integrated care. However, it also exposes significant methodological complexities: in FRONE, integrating quantitative RCT data with qualitative process data requires adaptive protocols and close coordination among research and clinical teams.

Moreover, recruiting and maintaining patient participation across all steps of the stepped-wedge design poses additional challenges, demanding sustained engagement strategies and operational flexibility at each site. In IMPLEMENT, collecting comparable cost and pathway data across heterogeneous health systems challenges data harmonization and demands flexible analytic frameworks. To ensure meaningful cross-site and cross-country comparison, case vignettes were developed to standardize reference scenarios, allowing researchers to align trajectory and resource-use data across diverse clinical and organizational contexts. Across both studies, aligning economic, process, and implementation evaluations requires iterative synthesis and co-interpretation among multidisciplinary researchers.

 

Implications:The GERONTE hybrid design offers a unique lens for advancing implementation science in integrated care. By coupling experimental and observational evidence, it demonstrates how multi-layered data collection and synthesis can inform not only the effectiveness of integrated models but also the feasibility and sustainability of their implementation in diverse European contexts. The lessons learned from FRONE and IMPLEMENT provide methodological guidance for future evaluations seeking to bridge clinical outcomes with real-world transformation of care systems.