Reverse translating parkrun’s scale-up success: lessons for public health

Introduction: The scale-up evaluation field has been limited by a conceptualisation of success dominated by quantitative spread and restriction to purposively and centrally disseminated initiatives. Empirical research shows, however, that working definitions of scale-up success are far more varied, nuanced, and context-dependent. Moreover, excluding examination of organically scaling initiatives has narrowed what may be learnt about sustainable dissemination. Theory: To demonstrate the value of a multidimensional definition of scaling up success, we apply one borrowed from educational reform evaluation, comprising reflection on four interrelated elements of success: depth, sustainability, spread, and shift in reform ownership. We additionally consider the dimension of equity in scaling up. Method: We applied each dimension to the global physical activity phenomenon ‘parkrun’, which while meeting the commonly used indicator of scale-up success, quantitative reach, is atypical in that spread is community-driven rather than purposeful. Results: Our analysis revealed novel system-level mechanisms behind scale-up success (e.g., custodianship vs ownership) and processes by which the sustainability of initiatives may be embedded in operational practice. The broader frame for the analysis of success was able to accommodate and learn from parkrun’s devolved dissemination model, extending previous, more narrowly focused analyses of scale-up success. For example, as an organically disseminating initiative, parkrun highlighted the importance of evaluating the role and potential of social networks in scaling up. Discussion: We show that using multidimensional definitions of scale-up success and including organically disseminating initiatives can provide new insights and strategies for sustainable and equitable dissemination of public health initiatives.