Abstract
BACKGROUND: Implementation costs-the combined costs of delivering expert support and participating in an implementation endeavor-are often omitted from economic evaluations. When included, delivery and participation costs are usually combined, even though these may be covered by different funders. We propose a pragmatic micro-costing approach that separates the delivery and participation costs as well as outlines practical considerations for measuring implementation costs. METHODS: Sixty-four specialty addiction treatment programs and primary care clinics participated in a stepped sequence of implementation strategies focused on improving access to buprenorphine and naltrexone for persons with opioid use disorder. The implementation strategies deployed were: audit and feedback (A&F), a two-day workshop, internal facilitation, and external facilitation. Our micro-costing approach separately measured the cost to deliver and participate in implementation strategies, as demonstrated through the A&F case example, which was the first of four implementation strategies deployed. We applied the following practical considerations to maximize the precision and accuracy of cost data: 1) Balance the frequency and length of cost survey, 2) Cost tracking training, 3) Regular survey reminders, 4) Tailor cost surveys, 5) Perform frequent cost data validation, 6) Iterative evaluation and refinement. RESULTS: In A&F, the implementation setup cost was $32,266, and the annual recurring costs were $4,231 per clinic. While the majority of the setup cost (99%) can be attributed to A&F delivery, over half of the annual recurring costs (63%) were attributed to clinic participation in A&F. CONCLUSIONS: This micro-costing approach appears both pragmatic and meaningful. By understanding the total cost implications of implementation, decision-makers can better select the most suitable strategy based on the context, goals, and budget constraints to efficiently optimize the pace and desired outcome of an implementation endeavor. TRIAL REGISTRATION: The trial protocol is registered with ClinicalTrials.gov (NCT05343793).