Efforts to scale up evidence-based health care interventions are seen as a key strategy to address complex health system challenges. However, scale-up efforts have shown significant variability. We address the gap between scale-up theory and practice by exploring the socio-cultural factors at play in the evaluation and scale-up of three interventions within the clinical field.

A qualitative multiple case study was conducted to characterize the evaluation and scale-up efforts of three interventions. We interviewed 18 participants, including clinicians and researchers across the three cases. Using Pierre Bourdieu’s concepts of field and capital as a theoretical lens, we conducted a thematic analysis of the data.

Despite the espoused goals of ensuring that health service interventions are always based on high-quality evidence within the clinical field, this study demonstrates that the outcomes of the evaluations are not the only factor in the decision to engage in scale-up efforts. Important socio-cultural factors also come into play. Bourdieu uses the term capital to refer to the resources that agents compete for and with their acquisition, accumulate power and/or social standing. The type of evidence valued in the clinical field and the ability to leverage capital in demonstrating that value are also important factors.

Determining if an intervention is effective and should be scaled up is more complex in practice than described in the literature. Efforts are needed to explicitly include the role of social processes in the current frameworks guiding scaling-up efforts.