Fidelity is the degree to which an intervention is implemented as its original developer intended. Interventions that are implemented with fidelity are more likely to replicate the results from the original implementation of the intervention than are those that make substantial adaptations. Training on how to implement the intervention, especially if it’s available from the program developer, will increase your ability to implement with fidelity.
However, although ensuring fidelity is an important concern, at times adaptation may be necessary tobetter fit your local circumstances. You may find, for example, that you are working with a target population that is in some way different from the population that was originally evaluated, or that some intervention elements must be adjusted due to budget, time, or staffing restraints. In these cases, it may be necessary to adapt the intervention to meet your needs. Balancing fidelity and adaptation can be tricky—any time you change a strategy or intervention, you may compromise the outcomes. Even so, implementing an intervention that requires some adaptation may be more efficient, effective, and cost-effective than designing a new intervention.
Here are some general guidelines for adapting an intervention:
- Select strategies with the best initial fit to your local needs and conditions. This will reduce the likelihood that you will need to make adaptations later.
- Select strategies with the largest possible effect size—the magnitude of a strategy’s impact. For example, policy change generally has a larger effect size than classroom-based programs.
Note: The smaller a strategy’s effect size, the more careful you need to be about changing anything. You don’t want to inadvertently compromise any good that you are doing. In general, adaptations to strategies with large effect sizes are less likely to affect relevant outcomes.
- Implement the strategy as written, if possible, before making adaptations, since you may find that it works well without having to make changes.
- When implementing evidence-based interventions, consult with the intervention developer when possible before making adaptations. The developer may be able to tell you how the program has been adapted in the past and how well these adaptations have worked. If the developer is not available, work with an implementation science expert or your evaluator.
- Retain the core components, since interventions that include these components have a greater likelihood of effectiveness. If you aren’t sure which elements are core, refer to the intervention’s logic model, if it is available, or consult the program developer or your evaluator for assistance.
- Stick to evidence-based principles. Strategies that adhere to these principles are more likely to be effective, so it is important that adaptations are consistent with the science.
- Change your coalition’s capacity before you adapt an intervention. While it may seem easier to change the intervention, changing local capacity to deliver it as it was designed is a safer choice.
Cultural adaptation refers to program changes that are culturally sensitive and tailored to a particular group’s traditional worldviews. Effective cultural adaptation is especially important when it comes to implementation.
Too often, people equate cultural adaptation with translation, but it is much more than that. Effective cultural adaptation considers the values, attitudes, beliefs, and experiences of the target audience. It depends on strong linkages to cultural leaders and access to culturally competent staff.