Implementation science can accelerate adoption and scaling of evidence-based services into real-world practice, ultimately increasing their impact on health outcomes and well-being. More specifically, implementation science has been defined as "the scientific study of methods and strategies to promote the systematic uptake of evidence-based innovations into routine practice, thereby increasing the quality and effectiveness of these services".¹ Application of implementation science principles boasts the ability to reduce the research-to-practice gap from 17 to 3 years.² For patients to benefit from timely provision of effective services, time to translation needs to be accelerated significantly. The pace of practice transformation efforts can therefore be positively impacted by use of implementation theories, principles, and frameworks.

The field of implementation science has matured in the last decade and, with it, an increased awareness of how it can advance pharmacy practice.²-⁴ The profession is noticing successful application of implementation science to pharmacy practice transformation efforts.³,⁵-⁷ Despite these successes, failures to implement well-researched health care services are still a reality.

One of the most often cited barriers to implementation is a lack of "fit" between the intervention and the practice setting.⁸ This fit issue has also been described by Proctor and colleagues as "appropriateness," one of the eight implementation outcomes typically included to assess implementation success.⁹ Appropriateness is defined as "the perceived fit, relevance or compatibility of the innovation or evidence-based practice for a given practice setting, provider, or consumer; and/or the perceived fit of the innovation to address a particular issue or problem." Similarly, Rogers identified compatibility as a core concept in his Diffusion of Innovation theory.¹⁰ Fit is recognized as a multi-faceted construct that should take into account various stakeholders' perspectives (e.g., providers, managers, team members, patients) and organizational levels (e.g., health system, clinic, or pharmacy).¹¹,¹² Several implementation frameworks include contextual fit as a critical pre-condition or pre-implementation step.¹³-¹⁵ Despite its recognized importance, the concept of fit has not been subject to extensive study. There is limited guidance on how to select an appropriate service or intervention and evaluate its compatibility with a given implementation environment.⁸,¹⁶ Unsurprisingly, we are continually confronted with this lack of guidance in our own work.

As colleagues with implementation science expertise, we often collaborate with pharmacists looking to implement new services. Through this work, we have experienced failed implementation efforts by seemingly ready organizations with the resources, capacity, and motivation to implement a new service or intervention. One example involved a project focused on implementation of comprehensive medication management (CMM) into a team-based, at-home care program. The program had significant investment from the organization, pharmacy leadership buy-in, motivated pharmacists who were committed and capable of delivering the intervention, and various implementation supports in place. Yet, after a year of trying to implement CMM in practice, this seemingly well-planned implementation effort was abandoned. When we probed into what happened, interviews and surveys from the practitioners and team members suggested that CMM did not fit the overarching goals of the organization and larger program. The organization's leadership wanted a program to stabilize acutely ill patients to prevent rehospitalization with pharmacists serving in transitional rather than longer-term roles with these patients. CMM, a longitudinal service designed to help manage chronic conditions, simply was not the right intervention for the needs of the overall program and organizational goals.¹⁷,¹⁸ This leaves one to wonder - why was it selected in the first place?

The need for appropriately selecting services that are compatible with the implementing context has been noted in the pharmacy practice literature.¹⁹-²² In one effort to implement a targeted medication adherence intervention in U.S. community pharmacies, both early adopters and traditionalist practices reported questioning the program's fit in light of the other services offered and given the larger chain pharmacy's vision.²⁰ Another study of professional pharmacy services in Australia reported that service fit with the needs of the patient population was rarely considered in early implementation efforts, but increased throughout implementation.²¹ Similarly, Turner et al. identified a positive association between the perception of how well the service fits with organizational mission and both implementation success and service reach.²² Finally, based on a recent study we conducted exploring the relationship between implementation readiness and early implementation outcomes, readiness levels were predictive of acceptability, feasibility, and intent to adopt, but not of appropriateness when accounting for clinic type. This result underscores the importance of determining fit prior to engaging in readiness building activities to maximize the benefits of this preparatory process. These examples highlight the need for implementers to thoughtfully examine how they select new pharmacy services or interventions within a given context.

KEY CONSIDERATIONS FOR ENSURING FIT

Ensuring selection of the appropriate intervention for the patient population, setting, and organizational goals early in the implementation process is critical for implementation success. Without carefully considering the compatibility of the service, a fit issue may not be realized until after significant resources and efforts have been expended. This can result in slowed progress and decreased motivation of stakeholders involved in the implementation process. Given the importance of ensuring fit, here are some key considerations implementers should thoughtfully assess when selecting an intervention or service in the pre-implementation phase. These considerations are derived from the National Implementation Research Network's Hexagon tool and the Wandersman and team's Getting to Outcomes framework, as well as our own professional experience.²³,²⁴

It is important to note that evaluating fit should be preceded by completion of several planning steps. Fit considerations hinge on understanding: the problem to be solved; the needs of the patient population that is being targeted; the objectives and metrics that need to be achieved by implementing this new service; and the available menu of relevant services and programs that are available for selection. The services considered should first and foremost have demonstrated evidence of effectiveness. Available data should be evaluated within the context of an organization's needs. Only effective interventions that align with the issue that needs to be addressed, the target patient population, and the outcomes of interest should be included in your menu of program options. Additionally, the service itself should be clearly defined with identifiable core components or features so that implementers can fully operationalize, replicate, and assess service effectiveness. Ensuring that the intervention is "usable" or defined well enough to ensure standardization of delivery across pharmacist and health care settings is critical to success.²⁵ The insights gained through this initial process are foundational to understanding and assessing the following fit considerations.

CONCLUSION

To avoid frustration, lost motivation, and, most importantly, limited impact on the patients in need, a service or intervention should fit the context in which it is being implemented. Ensuring fit between a service and the intended health care setting is a critical step to implementation success. In this commentary, we reviewed five key considerations that should be evaluated when exploring fit. Successful uptake and implementation hinges on careful planning and, most of all, appropriate fit between the service and the implementing context.