Translating science into practice in clinical psychology: A reformulation of the evidence-based practice inquiry model

Step one: Specify the key tasks

A significant innovation in our revision of the five-stage EBP inquiry process is to replace the Ask step, with its emphasis on asking questions, with a task-formulation step. Arguably, this is the most critical step and is the major focus of our depiction of the revised five-step model. This change has the advantage of making the problem description significantly richer than one formulated purely in terms of questions.

There are a variety of distinct tasks in clinical practice, each requiring the achievement of different types of knowledge. These tasks include problem detection and description, explanation, treatment, maintenance of treatment gains, and risk management. A major aim of science-informed practice is to utilize the best scientific theories and research evidence (i.e., scientific knowledge) available to the clinician to properly carry out these tasks. What we mean by scientific knowledge can be roughly characterized in the following way: “Scientific knowledge is high-grade knowledge, that is, knowledge that satisfies demanding epistemic standards and that, as a result, is highly reliable, robust, or well-established” (de Ridder, 2020, p. 4). However, as well as scientific knowledge, social, cultural, and commonsense knowledge is incorporated into the task description, thereby accounting for all the sources of data covered by the four circles of the EBP model. In other words, more than one type of knowledge is required when engaging in ethical and effective clinical work.

In accordance with the constraint-composition conceptualization of scientific problems described earlier, we argue that an important first step in developing an understanding of clinical phenomena and their management is to create as rich an initial description of them as possible. Each piece of relevant information becomes part of the task under consideration and serves to streamline and guide subsequent investigations. For example, formulating an explanatory task as one involving a young Indigenous male with a major depression, substance use disorder, and avoidant personality features who is struggling with a sense of cultural alienation and poverty. An individual such as this may be strongly motivated to reconnect with his Indigenous roots, value community-based interventions, and be suspicious of medical professionals. Each piece of relevant knowledge about individual clients becomes a component of the task description, and any diagnosis and case formulation should be constructed with these features in mind. The search for, and appraisal of, treatment options for someone falling under this description will be heavily constrained. Thus, right from the beginning, the task description constrains knowledge and relevant evidence, and serves to contextualize clients more. Unlike the standard EBP model, the revised model does this earlier on in the clinical decision-making process, rather than at the final application step. This helps to address the problems of information overload and intractability discussed earlier.

An obvious objection to requiring a front-end rich formulation of a task is that it may narrow things down to the point that any subsequent literature search will yield little valuable information, and even worse, may fail to identify effective treatments. In the example mentioned above, it could be argued that good quality treatments for depression and addiction might not have been undertaken for individuals who share the key features of being Indigenous, impoverished, culturally alienated, and so on. Thus, any potential advantage of a rich initial task description and the subsequent streamlining of an information search may be lost. Therefore, the relevant question becomes, how best to balance building in task constraints early on with ensuring that all effective treatments or assessment strategies are taken into account?

One strategy for balancing task constraints and treatment considerations is to include only those constraints that have been well supported in the literature, or are so well established by other means that it is reasonable to accept them as legitimate filters. This can be achieved by asking two questions at the outset of a clinical investigation (we focus on the task of treatment for convenience). First, are there any factors that preclude certain kinds of intervention, such as significant disabilities like severe autism, language problems, or significant personality dysfunction? This is a process of ruling out possibilities. If so, they should be regarded as filters or constraints and, therefore, as part of the formulation of the treatment task. The second question has two parts: (a) Are there any internal features of a condition, disorder, or persons that have been reliably established by research (or accepted as trustworthy knowledge) that can act as constraints? This could include distinctions between certain types of symptoms or symptom clusters such as anhedonia, diagnostic subtypes, gender, client preferences, and values. Then, (b) are there any external characteristics that have been reliably established by research (or are accepted as trustworthy knowledge) such as social class, cultural identification, or geography that are likely to markedly affect a person’s responsiveness to certain interventions? Question two rules in certain features as part of the problem, that is, as constraints that any satisfactory conceptualization, classification, explanation, treatment, and so on should consider. Deciding what constraints to use as task descriptors is a challenging problem and, in our view, one that ought to be guided by research and good theory. In any event, something like this filtering process occurs at step four in the standard EBP inquiry process and, therefore, faces similar problems, but at a later stage.

A notable aspect of our revision to the EBP five-step process is that values are a pivotal part of the method and provide an organizing point for clinical inquiry; they provide a normative searchlight that frames key problems and challenges. Clinical tasks such as problem description, or the planning and delivery of a treatment, always occur within a practice niche (context), which comprises the client’s characteristics, therapeutic resources, relevant knowledge, and environmental and organizational contexts. These are essentially the four circles of the EBP and collectively they are manifested at an individual level within a specific context; that is, the lifeworld of the client and practitioner. Each of the four EBP components contains goals and actions, which are incorporated into practices. More specifically, practices involve the application of practical knowledge within goal-directed action sequences, governed by a “structured body of norms” (Wallace, 2009, p. 11). Norms are evaluative in nature and spell out whether an activity is done properly and whether it meets the socially accepted relevant standards. Goals reflect values, the type depending on the task, and the actions designed to realize them. For example, diagnosis presupposes a conception of mental disorders, which are typically defined as conditions involving harmful dysfunction (Kendler et al., 2011), embodying prudential- and knowledge-related values respectively (Nielsen & Ward, 2020). The knowledge-related values are utilized in the process of deciding what mechanisms are associated with the dysfunction component of mental disorders, for example, an impaired threat detection system in anxiety disorders (Barlow, 2004). The prudential-related values are involved in establishing that, as a consequence of this psychological dysfunction, an individual is suffering and having problems coping in their day-to-day life (Wakefield, 1992). Each of the four circles of the EBP comprises both factual and normative elements, but at the very center are clients’ values, reflecting what is at stake for them. Is it social rejection, failure at work, self-recrimination, fear of persecution, or some other kind of disvalued state? To fully understand the nature of the relevant task, clinicians are obliged to grasp the core normative dimensions of encounters with clients. Values are pervasive and have direct and indirect influences on research and practice.

Step two: Acquire relevant information

In the standard EBP five-step inquiry model, the second step is that of acquiring relevant empirical evidence to answer the question posed in step one. Step two has a slightly different function in our revised model and instead seeks to take into account the relevant epistemic considerations pertinent to the task formulated in the first step. On the constraint-composition conceptualization of a problem, a task is a problem comprised of constraints that can be posed as a particular type of rich question. For example, if the task is to detect a disorder, then its formulation will include pertinent information about the patient’s presenting condition, social and cultural context, values, clinician expertise, agency resources, and relevant research findings (drawn from the four circles of the EBP model). A core clinical question will then be formulated and used to structure the systematic collection of clinically relevant data and ideas. In our revised model, a question is only posed once a task has been identified and at least moderately described in terms of the relevant constraints. Otherwise, the danger is that the subsequent inquiry will be unfocused and diffuse.

The nature of the information-acquisition process will vary depending on the specific practice task being undertaken and will likely draw from a mix of scientific theory and research, personal experience and clinical expertise, cultural knowledge, and common-sense folk psychological understandings. The critical difference in the revised inquiry model is that the concept of evidence is expanded to include a host of relevant justificatory considerations. These considerations may be empirical and derived from research studies using RCTs, or conceptual in the form of scientific models and theories, classification systems, methodological (epistemic) norms, ethical norms, and theory appraisal criteria. Thus, there is much more to well-reasoned research and practice than judgments based solely on empirical evidence; these judgments are also guided by logic, meaning, and a variety of epistemic standards. The worry that arises from centering the acquisition step of EBP on the collection of (empirical) evidence is that conceptual aspects of practice will be overlooked.

Introducing conceptual and theoretical resources into the second step of an EBP inquiry process will ensure that simple errors are not made early on in the investigation. For example, in the explanatory case-formulation phase of clinical practice, drawing from invalid diagnostic categories or using psychometric tests that have poor validity and reliability or are not simply fit for purpose (Younstrom et al., 2017) is likely to lead therapists down the wrong investigative path. This will have adverse knock-on effects and could result in poor downstream treatment decisions and suboptimal outcomes for clients.

With respect to the problems of EBP discussed earlier, our revisions to this step go some way to addressing them. First, because of the inclusion of conceptual issues in the acquire step, there is less chance of basing interventions on poor theories and problematic concepts because the process is in part guided by the explicit consideration of epistemic, ethical, and social values. Second, only information that is germane to the task being undertaken is collected, making this aspect of the inquiry process more targeted and efficient. Third, information is prioritized according to the task that drives clinical work. It will, therefore, be easier to address the problem of conflicting data or information. For example, if the task is one of selecting the best treatment option for someone with a major depression, then a meta-analysis, or systematic review, of RCTs will provide the strongest evidence. However, if instead a therapist is seeking to explain a client’s set of symptoms or problems, then a reliance on empirical evidence alone will not be enough. Epistemic considerations such as the explanatory coherence and depth of any theories appealed to when formulating the case will be of critical importance and may well trump empirical data.

Step three: Appraise information

The significant differences between our version of step three and the EBP inquiry model have their origins in the previous two steps: the task engaged in constrains the kind of information or “evidence” sought, which, in turn, has implications for the type of appraisal undertaken. The criteria employed to evaluate responses to task questions may be either empirical or theoretical, or both in some instances. Each set of criteria is underpinned by epistemic values such as validity, coherence, or logical consistency. Therefore, strict evidence hierarchies are not a requirement for the appraisal step of some tasks, and empirical evidence may not be relevant at all. To clarify these points, we will discuss the appraisal process with respect to the different tasks of detecting, explaining, and treating psychological problems.

The identification of problems such as symptoms or mental disorders is a signal-detection task, where clinicians are asked to discern clinically meaningful patterns in a sea of data. The detailed analysis and discovery of data patterns helps practitioners to make judgments about the likely existence of clinical phenomena, empirical regularities that indicate clinically relevant facts such as depressed mood, auditory hallucinations, or low self-esteem. An important methodological requirement in this signal-detection task is that the discovery of data patterns should be replicated, ideally by using multiple methods. Haig (2014) stresses the distinction between data and clinical phenomena (i.e., symptoms, signs, or problems) for which the data serve as evidence; some of the data will be “noise,” and other data markers of genuine phenomena. The ability to assess evidence in successfully detecting a problem depends in part on the convergent validity of different methods, whereas the methods themselves are evaluated through examining their psychometric properties (Younstrom et al., 2017).

According to our revised five-step inquiry model, the evaluation of a clinical explanation for a person’s problems should be based on more than its empirical adequacy. Just as scientific theories in general are underdetermined by the relevant empirical evidence (McMullin, 1995), so are psychological formulations. In any practice situation, there will commonly be several plausible case conceptualizations consistent with the clinical evidence. The clinician should, therefore, consider which of the number of competing case formulations provides the best explanation of a client’s symptoms or problems. As with a scientific theory, the evaluation of a case formulation will often involve the determination of its explanatory coherence in terms of the major criteria of explanatory breadth, simplicity, and analogy (Thagard, 1989, 1992). More generally, theoretical literacy, awareness of the normative nature of theory construction, and evaluation of a case formulation are crucial aspects of this third step.

Our last example of the third step in action is concerned with treatment selection. The choice of a science-informed intervention depends on existing knowledge and, although it makes sense to follow an evidence hierarchy, any decision to do so ought to be constrained by ethical and pragmatic considerations. A client’s values, cultural identity, and the resources available to practitioners will influence the way they go about deciding what the best treatment option is. It is important to consider the best available research evidence (e.g., from systematic reviews of RCTs) in light of client and resource information. Thus, an evaluation is multifaceted and should never be based on research evidence alone. The constraints built into the task identification, problem formulation, and information acquisition steps serve to determine what considerations are relevant and how they should be appraised. As discussed above, there are different evaluation strategies depending on the specific task being undertaken.

Step four: Construct and apply intervention plan

In the standard five-step inquiry model, it is at the application phase that clinicians explicitly consider information relating to the other three circles of the EBP model. In our view, consideration of these factors at this point is too late because of the problem of information overload and the sheer complexity of any well-made decision. Certainly, therapists do make good decisions using the standard model, but there is still room for significant improvement for assessing most disorders. Currently, treatments in psychology are not as effective as they could be (e.g., Craighead et al., 2015; Springer et al., 2018). Arguably, this situation could be due in part to problems of validity with current classification manuals (Berenbaum, 2013), as well as vague, heterogenous therapeutic targets such as major depressive disorders whose diagnostic criteria can be met by dozens of different clinical profiles (Fried & Nesse, 2015).

An additional possible (although speculative) explanation for the relatively weak therapeutic effectiveness of clinical psychology interventions is the persistent flaws in the EBP model, notably, the five problems discussed above. In the revised five-step model, clinicians apply and formulate intervention plans that contain guidelines about how to achieve the task within the relevant context by using appropriate knowledge. The nature of the intervention plan is constrained by the task and its formulation. The innovations made in the earlier steps exert an influence here, primarily by constraining the way the clinical problem is defined, classified, and explained.

Step five: Analyze and adjust plan

The standard five-step model is a dynamic, iterative process in which clinicians gradually adjust their plans. These plans will take different forms as intervention unfolds. Although treatment may begin as “a one size fits all” approach, this is adjusted if necessary to the unique features of the client and their situation (Spring et al., 2019). We argued earlier that this is a mistake and runs the risk of locking psychologists into an incorrect view of a client’s problems and a corresponding inappropriate intervention framework. Our suggestion was to utilize the constraint-composition depiction of practice tasks and their related problems at the beginning of inquiry and, in this way, ensure that consideration of a client’s relevant features are built in at an early stage. By considering a client’s prudential, ethical, and social values in direct relation to their clinical situation, the clinician will have a better idea of what is at stake for them, and what kind of intervention plan is likely to be acceptable. In addition, by paying greater attention to the conceptual aspects of the inquiry process, a greater focus will be placed on mechanisms of change and their relationship to treatment. This is a theoretical task, based on modeling mechanisms thought to constitute and cause psychological problems. To ascertain whether a treatment is working, and why, it is insufficient to rely on evidence from RCTs. RCTs will only tell you whether an intervention is more effective than other options but will not tell you why. And arguably, the “why” is what is needed for rational adjustments to a treatment plan, particularly if the initial treatment was based on incorrect theories, problematic diagnostic systems, or vague treatment targets (Ward & Clack, 2019).