Making Implementation Costing More Accessible: Initial Transdisciplinary Guidance for Researchers and Practitioners.

Introduction: Despite an increased interest in implementation costs, there is little to no practical guidance on Method: We assembled a team of implementation scientists and health economists working in various settings to identify central issues related to implementation costing. Our objective was to support the broad application of costing in implementation studies that is consistent, feasible, and can be practically applied. We engaged in a limited, iterative process of developing initial guidelines and soliciting feedback, consistent with principles of USE-EBPI (Usability Evaluation for Evidence-Based Psychosocial Interventions) methodology, to make refinements and enhance broad applicability. Results: We developed initial recommendations for a limited number of critical issues to advance the application of costing in implementation science and illustrated them using a study example. These issues were: (a) identifying relevant resource costs, (b) capturing resources using activity-based costing (ABC), (c) valuing resource units, summarizing and reporting, and (d) estimating replication and sustainment costs. We also emphasize the need to tailor approaches to meet different contexts and project-specific needs, and provide guidance when additional help may be needed. Conclusions: Key to ensuring any program's successful adoption, implementation, and sustainment is understanding the costs and resources required. Costing implementation in the "real world" is both an art and a science; teams must make decisions about give-and-take related to precision and burden on participants and the research team while still producing generalizable estimates. Transdisciplinary costing guidance can address these issues and provide details and resources to help pragmatically cost and report implementation efforts.