The interplay between a policy or intervention and its local context can impact both its implementation and its effectiveness(64, 65). For example, differences in culture, language, age and socioeconomic status of the target population can – and often do – influence successful implementation of a policy or intervention either positively or negatively(66). This means that a policy or intervention may need some adaptation.
Adapting a policy or intervention to the context in which it will be delivered is a delicate balancing act: on the one hand adaptation is crucial to ensure relevance to the local context, improve feasibility, increase local pertinence and adoption, encourage fidelity, foster sustainability and maximize effectiveness; on the other hand, one has to be careful not to modify the policy or intervention so much that fidelity to some of the core components of the policy or intervention is lost and effectiveness is threatened.
Guidelines on the adaptation of interventions typically share the following steps:
- identifying differences between the population for which the policy or intervention was initially designed and the new target population;
- identifying which component(s) of a policy or intervention need to be adapted;
- making modifications to the policy or intervention;
- piloting the modified policy or intervention.
The Method for Program Adaptation through Community Engagement (M-PACE) developed by Chen et al.(66) outlines a way of systematically adapting interventions to a new setting. This involves convening an adaptation steering committee (including experts who can advise on whether an element of a policy or intervention can be changed without reducing effectiveness) and then exposing a limited group of participants to the unadapted intervention. This is followed by collecting participant and instructor feedback after each implementation session (if appropriate), or conducting a pilot through individual interviews and then conducting focus groups with participants and instructors at the end of the intervention (or pilot). Further details about M-PACE can be found in reference(66).
When adapting a policy or intervention it is important to know that certain elements are essential for desired outcome(s). These elements are known as evidence-based kernels and can be likened to a drug’s active ingredients, without which its effects would be lost(66). Therefore, as far as possible, these kernels should not be modified. However, methodically determining the kernels of a policy or intervention is not typically feasible – it requires the same intervention to be implemented multiple times, with the presumed kernel being changed each time the intervention is re-implemented while other variables are kept constant. Although research teams have successfully articulated and validated the kernels of some programmes(63, 67-70), there are few adequately defined programmes in the research literature. The amount of evidence for evidence-based kernels in different fields should grow with increasing recognition of the importance of implementation research.
The case study below gives an example for how an intervention was adapted to the local context.
2.1 Social validity: how acceptable is the policy or intervention in your local context?
Despite a policy or intervention being highly effective at achieving a desired outcome, its implementers and/or consumers may consider it inappropriate for a particular setting. In order for a policy or intervention to achieve intended outcomes in the practice setting, it must be both effective and socially valid. A programme is said to have social validity when it addresses problems considered relevant by consumers, it does so in a manner that consumers can enjoy or at least tolerate, and it produces outcomes that are considered valuable.(71)
A social validity assessment can provide information regarding how well specific elements of a policy or intervention are liked or disliked. Most current approaches define three elements of a policy or intervention that can be assessed for their social validity.(73) These are:
- the social significance of the goals of policy or intervention,
- the social appropriateness and acceptability of the policy or intervention’s procedures and
- the social importance of the effects or the outcomes produced by policy or interventions.
Most methods for assessing social validity ask parties other than policy-makers or researchers about their opinions on policies and interventions(71) and use questionnaires/rating scales and focus groups or interviews.(72) Below, you can find and download a proposed structure for assessing the social validity of a policy or intervention.