Background: Implementation fidelity is critical to the internal and external validity of implementation research. Much of what is written about implementation fidelity addresses fidelity of evidence-informed interventions rather than fidelity of implementation strategies. The documentation and reporting of fidelity to implementation strategies requires attention. Therefore, in this scoping review, we identify the extent and quality of documentation and reporting of fidelity of implementation strategies that were used to implement evidence-informed interventions.

Methods: A six-stage methodological framework for scoping studies guided our work. Studies were identified from the outputs of the Effective Practice and Organization of Care (EPOC) review group within the Cochrane Database of Systematic Reviews. EPOC's primary focus, implementation strategies influencing provider behavior change, optimized our ability to identify articles for inclusion. We organized the retrieved articles from the systematic reviews by journal and selected the three journals with the largest number of retrieved articles. Using a data extraction tool, we organized retrieved article data from these three journals. In addition, we summarized implementation strategies using the EPOC categories. Data extraction pertaining to the quality of reporting the fidelity of implementation strategies was facilitated with an "Implementation Strategy Fidelity Checklist" based on definitions adapted from Dusenbury et al. We conducted inter-rater reliability checks for all of the independently scored articles. Using linear regression, we assessed the fidelity scores in relation to the publication year.

Results: Seventy-two implementation articles were included in the final analysis. Researchers reported neither fidelity definitions nor conceptual frameworks for fidelity in any articles. The most frequently employed implementation strategies included distribution of education materials (n = 35), audit and feedback (n = 32), and educational meetings (n = 25). Fidelity of implementation strategies was documented in 51 (71 %) articles. Inter-rater reliability coefficients of the independent reviews for each component of fidelity were as follows: adherence = 0.85, dose = 0.89, and participant responsiveness = 0.96. The mean fidelity score was 2.6 (SD = 2.25). We noted a statistically significant decline in fidelity scores over time.

Conclusions: In addition to identifying the under-reporting of fidelity of implementation strategies in the health literature, we developed and tested a simple checklist to assess the reporting of fidelity of implementation strategies. More research is indicated to assess the definitions and scoring schema of this checklist. Careful reporting of details about fidelity of implementation strategies will make an important contribution to implementation science.