2021-09-30, Massougbodji, José, Gogovor, Amédé, Tchoubi, Sébastien, Rhéault, Nathalie, Zomahoun, Hervé Tchala Vignon, Brundisini, Francesca, Laberge, Maude, Uwizeye, Claude Bernard, Assan, Odilon, Légaré, France

Introduction: Scaling science aims to help roll out evidence-based research results on a wide scale to benefit more individuals. Yet, little is known on how to evaluate economic aspects of scaling up strategies of evidence-based health interventions. Methods and analysis: Using the Joanna Briggs Institute guidance on systematic reviews, we will conduct a systematic review of characteristics and methods applied in economic evaluations in scaling up strategies. To be eligible for inclusion, studies must include a scaling up strategy of an evidence-based health intervention delivered and received by any individual or organisation in any country and setting. They must report costs and cost-effectiveness outcomes. We will consider full or partial economic evaluations, modelling and methodological studies. We searched peer-reviewed publications in Medline, Web of Science, Embase, Cochrane Library Database, PEDE, EconLIT, INHATA from their inception onwards. We will search grey literature from international organisations, bilateral agencies, non-governmental organisations, consultancy firms websites and region-specific databases. Two independent reviewers will screen the records against the eligibility criteria and extract data using a pretested extraction form. We will extract data on study characteristics, scaling up strategies, economic evaluation methods and their components. We will appraise the methodological quality of included studies using the BMJ Checklist. We will narratively summarise the studies' descriptive characteristics, methodological strengths/weaknesses and the main drivers of cost-effectiveness outcomes. This study will help identify what are the trade-offs of scaling up evidence-based interventions to allocate resources efficiently.