An Introduction to Implementation Science for the Non-Specialist

"Without concerted attention to evidence-based implementation strategies, learning healthcare systems risk developing massive, expensive repositories of information without adequate strategies to actually utilize such data for system change."

The purpose of the field of implementation science is to improve the quality and effectiveness of health services by facilitating the systematic uptake of research findings and other evidence-based practices (EBPs) into routine clinical practice. This review introduces non-specialist investigators, administrators, and policymakers to the principles and methods of implementation science. Though it features examples from studies funded by the United States (US) Department of Veterans Affairs (USVA), the field of implementation science is a global one.

First, the review defines implementation science, comparing and contrasting it to the methods of quality improvement (QI) and dissemination. Recognition of the need for research that more directly impacts public health inspired this field, which involves trans-disciplinary research teams that include members who are not routinely part of most clinical trials, such as health services researchers, economists, sociologists, anthropologists, organisational scientists, and operational partners including administrators, frontline clinicians, and patients. Implementation science typically begins with an EBP that is under-utilised, and then identifies and addresses resultant quality gaps at the provider, clinic, or healthcare system level.

The review then traces the development of implementation science as a field. Among the oldest programmes focusing on implementation is the USVA's Quality Enhancement Research Initiative (QUERI). Since its inception in 1998, the goal of QUERI has been to improve military veterans' health by supporting the more rapid movement of effective interventions into practice.

Next, the review examines the principles and methods of implementation science. As is explained here, implementation processes are distinct from clinical trials that produce the EBPs they seek to implement. Implementation interventions may include, for instance, efforts to change behaviour at the patient, provider, system, or policy level - e.g., through education/training, audit-feedback, and performance incentives (provider level). The crux of implementation studies is their focus on evaluating the process of implementation and its impact on the EBP of interest. These studies can involve one or more of three broad types of evaluation, which are described in the review: process evaluation, formative evaluation, and summative evaluation. Data can come from various sources and can include either or both of quantitative and qualitative data.

Implementation strategies are typically multi-component and must adapt to local contexts. Thus, the endeavour requires clear, collective, consistent use of theory to build knowledge about what works, where, and why. The review distinguishes the terms theory, model, and framework. It provides an example of using a framework to guide data collection and analysis.

The review outlines the fundamentals of controlled intervention trials, which differ from other types of health services and clinical trials in that they focus on the impact of the implementation strategy on the use of an EBP, rather than the health impact of the EBP itself. In addition, they take a fundamentally different approach to validity, as is illustrated by a hypothetical trial of motivational interviewing (MI) for substance use disorders in the homeless population. The review explores the developing area of hybrid effectiveness-implementation designs, which pose hypotheses regarding both EBP and implementation effects, typically measuring both healthcare processes (implementation outcomes) and health status (intervention outcomes).

A brief description of two USVA QUERI projects illustrates some of the concepts covered in this review: (i) incentives in substance use disorders (type I hybrid design); and (ii) implementing pharmacotherapy for alcohol use disorders (formative evaluation). With regard to the latter example, the Theory of Planned Behavior was used as a guiding theory because the desired behaviour change was primarily at the individual level - e.g., convincing providers and patients to consider pharmacotherapy as a viable intervention option for alcohol use disorders. Implementation strategies selected for providers included social marketing, access to peer expert consultants, feedback on prescribing rates, and education and decision support tools. Direct-to-consumer mailings were selected as the intervention to address lack of patient awareness of medication options and potential negative peer attitudes toward pharmacological treatment of alcohol use disorder and to encourage patients to discuss alcohol use with their primary care provider. The implementation strategy was evaluated using an interrupted time-series design with controls. Prescribing rates were monitored for 9-month pre-implementation, implementation, and post-implementation phases for intervention facilities and matched control facilities. Formative evaluation led to refinements of the implementation strategy.

The review closes by placing implementation science into the context of global health policy. Publication venues such as Implementation Science, BMC Health Services Research, and a variety of specifically themed journals highlight the fact that maximising healthcare value has become a policy imperative globally. The idea is that healthcare systems need to act on data to improve practice, and implementation science provides a systematic set of principles and methods by which to accomplish this.