PROJECT SUMMARY There is a fundamental gap in understanding the causal mechanisms by which strategies for implementing evidence-based practices address local barriers to effective, appropriate service delivery. Continued existence of this gap represents an important problem because, until it is addressed, scientific knowledge and practical guidance about which implementation strategies to use in which contexts will remain elusive. The long-term goal is to develop the evidence base and practical utility of implementation science through mechanisms- focused implementation research. The objective of this application is to overcome critical problems blocking progress in implementation science and practice by identifying plausible strategy-mechanism linkages, developing causal models for mechanism evaluation, producing the measures needed to evaluate such linkages, and making these models, methods, and measures available in a user-friendly website. The rationale is that, once strategy-mechanism linkages are identified, implementation scientists can develop tailored implementation strategies and generate more robust evidence about which strategies work best in which contexts. Moreover, practitioners will be better able to select implementation strategies to address their specific implementation problems. The specific aims are: (1) build a database of strategy-mechanism linkages and associated causal pathway diagrams; (2) develop psychometrically strong, pragmatic measures of mechanisms; and (3) develop and disseminate a website of implementation mechanisms knowledge for use by diverse stakeholders, through the application of iterative user-centered design and social marketing principles. For the first aim, qualitative inquiry, Group Nominal Technique, Delphi methods, and causal diagramming will be used to identify and confirm plausible strategy-mechanism linkages and articulate moderators, preconditions, and proximal and distal outcomes associated with those linkages. For the second aim, rapid- cycle measure development and testing methods will be employed to create reliable, valid, pragmatic measures of six mechanisms for which no high-quality measures exist. For the third aim, we will develop a user-friendly website and searchable database via user-centered design and disseminate those using social marketing principles. This project is innovative because it shifts the current paradigm from evaluating implementation strategy general effectiveness to a mechanisms-informed approach that promises accelerated scientific progress. The proposed research is significant for its potential to vertically advance implementation science by developing micro-theories, methods, and measures for mechanism identification and evaluation. New horizons in implementation strategy development, optimization, evaluation, and deployment are expected to be attainable as a result, which will lead to enhanced implementation of evidence-based interventions for cancer control, and ultimately improvements in patient outcomes.

PROJECT NARRATIVE The proposed research is relevant to public health, and specifically cancer control, because the specification of causal mechanisms of implementation strategies—coupled with the development of models and measures to evaluate them—supports effective implementation of evidence-based practices. Our approach to implementation facilitates development and deployment of implementation strategies that target local barriers to evidence-based practice in cancer care settings, enhancing service delivery and patient outcomes. The relevance to NCI's mission of ensuring that evidence-based practices are effectively delivered and positively affect individual and population health.