To gauge the added value of a new EBP model, it is helpful to recall the primary criticisms of EBM: the evidence is too narrowly defined; the role and value of practitioners and their expertise are unclear; resources and/or contextual factors are ignored; and not enough attention is paid to clients’ preferences. These criticisms become particularly relevant to the behavioral and social science aspects of health, whose evidence base is much less extensive than in medicine and in which causality is nearly always determined by several factors. Therefore, it is important to define evidence broadly. For example, evidence may involve quantitative data (e.g., numerical results of program or policy evaluations) and qualitative data (e.g., nonnumerical observations collected by focus groups). As noted in regard to the discipline-specific evidence-based practice models, evidence may be narrowly defined and placed in a hierarchy (i.e., pyramid of evidence), or it may draw more broadly from sources like quality improvement or patient satisfaction data and consequently weight those categories more equally (e.g., EBN). The perceived value of evidence may vary by stakeholder type. Ultimately, the most useful evidence in a particular situation depends on the type of question asked about a specific practice or policy.
It is particularly helpful to see how each discipline has used the original EBM models to address specific shortcomings. Nursing, public health, and social work expanded the scope of what is considered evidence. They confirmed that many different practice questions are important and that the best study design depends on the question asked. Psychology specified criteria for “empirically supported treatments” and has, perhaps, been most successful in introducing these treatments to training programs. Both psychology and social work have emphasized the importance of clients’ characteristics as potential moderators of outcome. Social work also has made important changes in EBM that draw attention to institutional and environmental contexts. Public health addresses the mostly ignored issue of how resource availability influences decision making. Finally, both nursing and psychology have recognized the importance of patients’ characteristics and preferences to final decisions regarding clinical care. Although each of these discipline-specific models has particular strengths, none takes into account the vagaries of practice across the health professions.
Our revised EBP model () has a transdisciplinary perspective. It incorporates each discipline’s most important advances and attempts to address remaining deficiencies. The model is grounded in an ecological framework and emphasizes shared decision making. We used an ecological framework because intervening solely with individuals often is insufficient to maximize long-term gains for the population as a whole. Both the impact on the population and health maintenance can be enhanced by intervening also at the interpersonal, organizational, community, and public policy levels.
The model’s new external frame contains environment and organizational factors to create a cultural context that moderates the acceptability of an intervention, its feasibility, and the balance between fidelity and adaptation that is needed for effective implementation. Environment and organization are important to evidence-based decisions in all disciplines, although some disciplines, such as nursing, social work, and public health, may be more likely to choose or modify evidence-based interventions based on context. Nursing’s practices are organizational, and the feasibility of its practice recommendations is modified by governing policies, purchasing agreements, and affiliations. Because it is a social science, social work naturally incorporates attributes of the client’s environment into the plan of care. With the goal of preventing disease in populations, public health interventions must be implemented through organizations and communities. Albeit to a lesser extent, context is incorporated into decision making even when the treatment focuses on the individual patient, as in medicine and psychology. The diagnosis and treatment of a patient’s disease may require a stronger emphasis on the patient’s and provider’s characteristics, with a diminished role for context.
Consistent with major EBM models, “best available scientific evidence” remains one of the three circles. Evidence
is defined as research findings derived from the systematic collection of data through observation and experimentation and the formulation of questions and testing of hypotheses. In accord with the 1996 EBM model but differing from the 2002 version, clinical state and circumstances are no longer a circle (Haynes, Devereaux, and Guyatt 2002
; Haynes et al. 1996
). Because we regard state and circumstances as attributes of the patient, community, or population, we include them in the circle containing all that entity’s values, preferences, and characteristics.
As in the 1996 template, the practitioner’s expertise occupies a prominent place. We see expertise as one of many resources needed to implement health services and as one of four categories: competence at performing the EBP process, assessment, communication/collaboration, and engagement/intervention. EBP process skills are proficiency in formulating answerable practical questions, acquiring and appraising relevant evidence, applying that evidence through shared decision making that considers the client’s characteristics and resources, analyzing outcomes, and adjusting as appropriate. Assessment skills are competence in the appraisal of care recipients and expertise in implementing and evaluating the outcome of a needed health procedure. Communication and collaboration skills entail the ability to convey information clearly and to listen, observe, and adjust to arrive at an understanding and an agreement on a course of action. Engagement and intervention skills refer, at a minimum, to proficiency at motivating interest, constructive involvement, and positive change from stakeholders.
We have reconceptualized clinical expertise in a particular intervention or technique as a resource to be evaluated as part of the decision-making process. The expert’s role still differs from that of an educated consumer of EBP recommendations to the actual producer of primary research evidence to the synthesizer of evidence for EBP guidelines.
At the center of our model is decision making; the cognitive action that turns evidence into contextualized evidence-based practices. We had four reasons for moving decision making to the center of our model and practitioner’s expertise to a lower circle. First, we found that decision making was not a particular individual’s inherent professional or intuitive skill but, rather, a systematic decisional process combining evidence with the client, resources, and context. Second, we felt that the central emphasis on the practitioner’s expertise was inconsistent with the lack of empirical support for the proposition that the practitioner’s performance improved with experience (Choudhry, Fletcher, and Soumerai 2005
). Third, we placed decision making in the center of the figure to demonstrate the great difficulties and practical challenges in reconciling the many variables needed to make evidence-based decisions about clinical care, public health, or public policy. The evidence often is at odds with a patient’s or a population’s preferences. Similarly, resources (including expertise) may not be available to deliver what both the evidence and the patient’s/population’s preferences demand. By highlighting the nuances of data collection and decision making in the various disciplines (e.g., elevating patients’ preferences in nursing, more heavily weighting quantitative research evidence in medicine), and providing a transdisciplinary model that represents equally all the various inputs, a practitioner using the new EBP model can more collaboratively discuss the conflicts at hand. Moreover, the emergence of these conflicts may help policymakers direct resources to providers’ training, patients’ education, and communities’ development.
Finally, we are committed to a model of collaborative health care practice in which health decisions are not solely the practitioner’s but are shared among the practitioner(s), clients, and other affected stakeholders. Even though current models of shared decision making offer guidance when decisions are made by a dyad (i.e., practitioner and patient), relatively little is known about interprofessional decision making in a team-based or transdisciplinary practice (Légaré et al. 2008
; Whitney 2003
). Légaré and colleagues observed that true interprofessional decision making would require sharing the goal of health care decisions based on patients’ values, a sense of trust among professionals, and leadership and organizational structures that facilitate shared decision making in clinical care (Légaré et al. 2008