How does Kailo work to improve adolescent mental health? A developmental realist evaluation protocol

Background: Kailo is a community-centred research and design initiative that aims to improve adolescent mental health by addressing its wider social determinants. Unlike conventional interventions that often neglect systemic factors, Kailo employs a complex systems approach to identify and address the social causes of poor adolescent mental health in two pilot sites. This protocol outlines a developmental realist-informed evaluation that will develop, test, and refine the programme theory underpinning the Kailo framework. This evaluation will generate recommendations for the enhancement of Kailo before it is implemented in additional sites. Methods A developmental realist-informed evaluation will be conducted to investigate how and why Kailo works, for whom, and under what circumstances. This mixed-methods evaluation will engage key members of the Kailo consortium, local stakeholders, and young people who have interacted with Kailo. The initial phase incorporates a rapid realist synthesis, interviews with key informants, observations, and document analyses to formulate the initial programme theory. The second phase will employ semi-structured interviews, focus group discussions, observations, and analyses of routinely collected data to test the initial programme theory. The final phase will use focus group discussions to refine and consolidate the initial programme theory. Given the developmental nature of this evaluation, this programme theory will refine the implementation of the intervention in the pilot sites and generate recommendations to improve future versions of the Kailo framework. Discussion This study will explore the mechanisms by which the implementation of Kailo improves adolescent mental health by facilitating place-based systems change in the two pilot locations. This theory-based evaluation will illuminate the primary contextual conditions and mechanisms which produce intended (and unintended) outcomes to inform the future development of the Kailo framework. Moreover, the methodological approach used may contribute to broader understanding of how to implement and evaluate complex interventions designed to improve public health.