Using Evidence-Based Constructs to Assess Extent of Implementation of Evidence-Based Interventions. Fidelity of Implementation: To what extent are the core content, pedagogical, and implementation components of an intervention being implemented?


One set of implementation milestones involves Fidelity of Implementation. “Fidelity is the faithfulness with which an intervention is implemented; that is, how well the intervention is implemented without compromising its core content, pedagogical, and implementation components which are essential for the intervention’s effectiveness” (National Resource Center for HIV/AIDS Prevention Among Adolescents, n.d.). Implementing an intervention with fidelity improves the likelihood of replicating positive intervention effects (see the Administration for Children and Families, n.d., for more information).

One way to think about and measure fidelity is to identify the major components of a change. In a recent research brief developed by the Office of the Assistant Secretary of Planning and Evaluation titled Core Intervention Components: Identifying and Operationalizing What Makes Programs Work, Blase & Fixsen (2013) described core components as “the essential functions or principles, and associated elements and intervention activities (e.g., active ingredients, behavioral kernels) that are judged necessary to produce desired outcomes” (Embry, 2004, p. 2). Century, Cassata, Rudnick, and Freeman (2012) have proposed a framework for measuring the “enactment of innovations,” which includes identifying the characteristics of fidelity. In these works there is an expectation that practitioners develop fidelity gradually with practice instead of suddenly halting what they are doing and fully implementing a new approach.

An important first step when implementing an intervention is to establish what achieving fidelity will look like for that intervention and then establish what indicators will suggest progress in achieving fidelity. This involves identifying the critical components of an intervention, and then identifying steps during the implementation process that practitioners are likely to take as they move toward implementing intervention practices.

We recognize that at any point in time there will be variation in how well each component of the innovation is being used. For example, in a counseling program the assessment component might be implemented very well, but the feedback sessions leave key elements left out, suggesting partial fidelity of the whole program. This can be described in terms of different “Innovation Configurations” (Hall & Loucks, 1981; Hall & Hord, 2015), where each configuration represents a different combination of the components. As fidelity increases, more and more core components are included and are used as intended. In the final, "ideal" configuration, all critical components are in use and full Fidelity of Implementation has been achieved.

Important questions about fidelity must be addressed for each change initiative. How will the key components of the change be identified? Who will monitor the extent to which core components have been established and are being performed consistently? What data collection method will be used? How much information is needed? How frequently should fidelity milestones be measured? What standards will be used to interpret what is found? These are challenging decisions that have to be answered on a case-by-case basis; answers depend on the particular change being introduced. For example, Chinman et al. (2005) addressed some of these questions in their work about building community capacity for effective preventive interventions, including how to identify core components.


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