4: Designing Interventions

Designing Interventions

Health interventions should be carefully designed or developed to enhance their potentials to successfully address health problems (Moore et al., 2019). This can be achieved by following a systematic process, in which the interventions are grounded in an understanding of the problem and designed to match the manner in which the problem is experienced by the target client population, in the context of interest (Beck et al., 2019; van Meijel et al., 2004). Results of systematic reviews indicate that interventions developed through a systematic and structured process such as intervention mapping are effective in addressing the respective health problem (e.g. Fassier et al., 2019; Garba & Gadanya, 2017; Lamort‐Bouché et al., 2018).

In this chapter, the process for designing interventions is described and illustrated with an example. Approaches for delineating the intervention’s active ingredients are discussed. The intervention design process results in the generation of the theory of implementation and the theory of change that clarifies the intervention components and mechanism of action, respectively.


Intervention mapping (Bartholomew et al., 2016) is a systematic, well‐structured process that is useful for designing interventions. Intervention mapping has been recently applied to design health interventions aimed at promoting performance of health behaviors including physical activity (e.g. Direito et al., 2018; Krops et al., 2018), engagement in screening tests (e.g. Besharati et al., 2017; Byrd et al., 2012), and self‐management in chronic illness (e.g. Beck et al., 2019; Burrell et al., 2019). Intervention mapping has also been applied to design public health interventions (e.g. Abbey et al., 2017, Belansky et al., 2013) and implementation interventions that facilitate the adoption of clinical guidelines or evidence‐based interventions in practice (e.g. Caminiti et al., 2017; Chambers et al., 2019), as well as to adapt evidence‐based treatments to the local context (e.g. Koutoukidis et al., 2018; Perry et al., 2017).

Intervention mapping consists of a clearly described process for developing interventions that focus on changing health behaviors (Bartholomew et al., 2016; Kok et al., 2016). The process begins with an analysis of the health behavior to identify what needs to be changed, followed by the creation of matrices that combine change objectives with determinants of the health behavior, selection of theory‐based intervention methods, translation of these methods into practical application, and integration of the practical applications into an organized program. In addition to theory, relevant evidence synthesized from the literature and input from stakeholder groups including clients, are integrated in the process. The application of the mapping process culminates in the design of interventions that are informed by theory and that match or are responsive to the target client population’s experience of the health problem (Beck et al., 2019; Brendryen et al., 2013; Dalager et al., 2019).

The mapping process described next is adapted to enable the design of interventions addressing a range of health problems such as symptoms and cognitions, in addition to behaviors. The application of the steps comprising the process is illustrated with the design of an intervention for the management of insomnia.

Step 1 – Clarify the Health Problem

Clarification of the health problem is done by reviewing the theory or the logic model of the problem (detailed in Chapter 3). It is important to be familiar with the conceptual definition of the problem, as well as its indicators, level of severity, duration, determinants, and consequences, and to understand the direct and indirect relationships among the determinants and the problem experience. Special attention is given to the problem’s indicators and determinants, and the explanations of the pathways linking the determinants to the problem. A lucid understanding of the problem is essential to guide the next steps of the intervention design process. The theory of the problem, exemplified for insomnia, is illustrated in Table 3.1. The theory summarizes the determinants, indicators, and consequences of insomnia.

Step 2 – Analyze the Health Problem

Analysis of the health problem is a foundational step in the process of designing interventions. The analysis consists of critically reviewing the theory of the problem (see Chapter 3) to determine “what about the problem needs to and can be changed” in order to prevent, manage, or resolve the problem. The analysis involves a critical and meticulous examination of: (1) the conceptual definition of the health problem, which highlights the nature of the problem and provides a general hint on its amenability to change; for example, a problem that is genetic in nature may be difficult, if not impossible, to change whereas unhealthy behaviors or cognitions are potentially modifiable; (2) the operational definition of the problem into attributes that are specified in respective indicators, which point to indicators that are potentially changeable; and (3) the determinants of the problem, which identify those potentially modifiable. The meticulous examination contributes to a judgment as to what can be actually changed (also referred to as aspects of the problem): the overall problem, some or all its indicators, or some or all its determinants (Araújo‐Soares et al., 2018; Bello & Pillay, 2019; Besharati et al., 2017; Bleijenberg et al., 2018; Wight et al., 2016).

The judgment is based on logical thinking relative to the amenability of the problem, its indicators and determinants to change. The judgment is also informed and endorsed by the propositions of the middle range theory underpinning the conceptualization of the problem (selected if the theoretical approach is used to gain an understanding of the problem—see Chapter 3), the empirical evidence integrated to support the experience of the problem and its indicators and the association with its determinants (as is done if the empirical approach is used), and/or the explanations provided by stakeholder groups (as is done if the experiential approach is used).

The middle range theory of the problem provides statements about the conceptualization of the health problem and its associations with determinants. The theory also points to specific aspects of the problem that are malleable and have the greatest scope of change (Bleijenberg et al., 2018; Wight et al., 2016). These changeable aspects become the target of the intervention; that is, the intervention is designed to manage these aspects, with the ultimate goal of successfully addressing the health problem. For example, the social cognitive theory is frequently used to inform the conceptualization of health behaviors and the design of behavioral interventions (e.g. Durks et al., 2017; Lamort‐Bouché et al., 2018). The social cognitive theory posits that (non)engagement in a behavior is influenced by: personal determinants such as cognitions (beliefs, attitudes, expected outcomes of the behavior); perceived behavioral control (self‐efficacy); and social determinants such as norms and peer influence. The theory highlights cognitions and perceived behavioral control as determinants most malleable to change (e.g. Ball et al., 2017; Dalager et al., 2019; Direito et al., 2018).

The empirical evidence synthesizes the results of quantitative and/or qualitative studies pertaining to the experience if the health problem and its determinants. The evidence indicates aspects of the problem, in particular determinants, that could be potentially targeted by the intervention. Specifically, relevant evidence shows that the determinants (1) are consistently (across studies) and significantly associated with the experience of the problem; (2) are prioritized or considered important in contributing to the problem by the target client population; and (3) change over time, either normally or following treatment. Evidence of change confirms that the determinants are potentially modifiable. For example, incorrect beliefs and expectations about sleep have been found to perpetuate insomnia, and to be modified as a result of cognitive therapy (e.g. Eidelman et al., 2016; Morin et al., 2007).

In the absence of a middle range theory and empirical evidence on the health problem, the judgment is formed on the basis of systematic analysis of the problem and logical thinking; both are done either by the researchers alone or in collaboration with experts, including health professionals and clients. For example, the theory of insomnia presented in Chapter 3 is used here to illustrate the application of this analysis. As mentioned in Table, insomnia is conceptualized as a learned behavior. It is manifested as difficulty initiating and/or maintaining sleep (indicators), and influenced by predisposing, precipitating, and perpetuating factors (determinants). The analysis begins by questioning the extent to which insomnia, as a learned behavior, can be altered directly. Logically, this may be possible but not easy due to the complexity of the behavior. The conceptualization of insomnia as a learned behavior suggests that it can be “unlearned” and substituted with other behaviors that promote sleep. This perspective points to the need for behaviorally based interventions to manage this problem, but it does not indicate the specific behaviors to be changed. The analysis then moves to other aspects of insomnia to determine their amenability to change.

The analysis involves a review of the indicators and determinants of insomnia. There is no theoretical, empirical, or clinical/practical proposition that suggests that the indicators of insomnia (e.g. difficulty falling and/or staying asleep) can be directly manipulated or changed. However, a review and critical analysis of the three categories of determinants points to the following logic: (1) predisposing factors are innate characteristics of persons with insomnia and accordingly, they are not modifiable; (2) precipitating factors are often out the persons’ control because they initiate or trigger poor sleep but dissipate once the persons start to experience insomnia; therefore they may not be changed at the time the persons start to experience insomnia and seek treatment; (3) perpetuating factors, representing behaviors and use of strategies or techniques that maintain insomnia are potentially modifiable—these behaviors can be unlearned and the strategies can be substituted with sleep‐promoting ones.

The analysis results in the identification of what about the problem or aspects are modifiable. The identified aspects are defined at the conceptual and operational levels, based on the information presented in the theory of the problem, or relevant theoretical and empirical literature. These definitions are useful in specifying the desired changes in the next step.

Step 3 – Identify Desired Changes

In this step, desired changes are delineated for each aspect of the health problem identified as modifiable (Burrell et al., 2019). The changes represent alterations that should take place in the respective aspects of the problem and, subsequently, contribute to the prevention, management, or resolution of the problem. The changes are expected to occur at the level (e.g. intraindividual, environmental) at which the respective aspects of the problem are experienced. Two types of desired changes are specified. The first type, referred to as “change objectives” in the intervention mapping process described by Bartholomew et al. (2016), defines what clients need to do or alter to induce changes in the respective aspect of the problem (Beck et al., 2019); they reflect behaviors, activities, or actions in which clients engage to modify the aspect of the problem. The second type of desired changes, referred to as “performance objectives” in the intervention mapping process, defines the alterations in the aspects of the problem (Ball et al., 2017) that clients are expected to experience. Thus, desired changes reflect significant milestones, that is, changes in condition that clients experience and in behaviors in which clients engage, in the pathway to prevent, manage, or resolve the health problem (Brendryen et al., 2013; Czajkowski et al., 2015).

The desired changes are stated clearly, concisely, and in observable terms that accurately depict what is the specific alteration to be experienced and what is to be done, and who should make the change. The changes may be hypothesized to take place sequentially, whereby the occurrence of one leads to another, ultimately resulting in the prevention of or improvement in the experience of the health problem. The specification of the desired changes is critical (1) for designing interventions; the changes inform the delineation of the active ingredients (in step 4) and (2) for understanding the mechanism of action (represented in the sequence of desired changes) that explains how the intervention yields improvement in the health problem (Brendryen et al., 2013).

The identification of desired changes is illustrated in the example of insomnia. Of the factors that perpetuate insomnia and that are amenable to change, two health behaviors, physical inactivity and smoking, are reported to influence sleep. The following sequence of changes in condition is desired to help clients avoid these behaviors:

  1. Heightened awareness of the general health‐related behaviors that affect sleep.
  2. Improved understanding of when, how, and why these behaviors interfere with sleep and contribute to insomnia
  3. Increased knowledge of recommended techniques for handling these behaviors and, hence, mitigating their interference with sleep.
  4. Enhanced self‐confidence or self‐efficacy in applying the recommended techniques.
  5. Enhanced ability/skills in applying the recommended techniques.
  6. Appropriate and consistent use of the recommended techniques.

Step 4 – Delineate Intervention’s Active Ingredients

The active ingredients of a health intervention are the specific therapies or techniques (called “intervention methods” in the intervention mapping process) that are hypothesized to bring about the desired changes and, consequently, induce improvement in the health problem (Bleijenberg et al., 2018; Wight et al., 2016). The specific techniques encompass information that is relayed to clients and behaviors that clients engage in to address the problem. The techniques are delineated for each aspect of the problem identified as malleable, and relative to the respective desired changes. The techniques should be consistent with the aspect of the problem and capable of inducing the desired changes. The conceptual correspondence or match among the aspect of the problem, active ingredient or technique, and desired changes is essential to ensure the design of interventions with great potentials for being effective in addressing the health problem in the client population and context of interest (Dohnke et al., 2018; Mesters, et al., 2018).

The active ingredients or techniques can be identified from relevant theory, relevant empirical evidence, and/or consultation with experts or stakeholder groups, as explained in Section 4.2.

Delineation of the intervention’s active ingredients is founded on logical reasoning. Logical reasoning is based on a thorough understanding of the nature of the aspect of the problem amenable to change and critical thinking of how it can be modified. The goal is to generate new or select available therapies or techniques that conceptually correspond with the nature of the problem or its aspects. This implies that the techniques should address the problem or its relevant aspects directly, effectively, and efficiently by triggering the respective desired changes.

In the example of insomnia, engagement in health behaviors (i.e. physical inactivity and smoking) perpetuates this sleep problem. To induce the desired changes identified for the behaviors in the step 3, it is logical to provide education (active ingredient 1) about the behaviors and how they interfere with sleep, and recommend techniques for handling them to produce desired changes 1–3, as well as to offer instrumental support (active ingredient 2) in applying the recommended techniques to induce desired changes 4–6.

Step 5 – Operationalize the Active Ingredients

In step 4, the intervention’s active ingredients are delineated at the conceptual level; as such they are broadly defined (e.g. provide education about factors contributing to the health problem and offer support in changing these factors). While important, conceptually delineated active ingredients may not give specific instructions for how to deliver them; therefore, they should be diligently operationalized in a manner that maintains correspondence between their conceptual definition and delivery. This correspondence is necessary to enhance construct validity of the intervention (Sidani, 2015).

Operationalization of the intervention’s active ingredients consists of:

  1. Specifying the components that represent the active ingredients: This is accomplished by operationally defining each active ingredient in a component. The operationalization of each component involves detailing the content or information to be relayed to clients, the specific behaviors or activities in which clients engage, and the recommendations that clients are to apply in their daily life in order to attain the desired changes specified relative to the aspects of the problem amenable to change.

    In the example of insomnia, education and support were delineated as active ingredients for addressing the health behaviors that perpetuate insomnia. To operationalize these ingredients, one should ask the questions: education about what in particular and what type of support is useful for changing these two determinants of insomnia? The answers should be very specific detailing:

    • The content of education: (1) inform clients of the health behaviors that perpetuate insomnia (what are the behaviors?)—for example, physical inactivity; (2) explain how the behaviors interfere with sleep (what is the pathway through which these behaviors lead to poor sleep and insomnia)—for example, physical inactivity influences circadian rhythm “synchronizers,” daytime physical and mental health, arousal and body temperature around bedtime, and sleep architecture (Chennaoui et al., 2015; Irish et al., 2015); (3) describe, in detail, the recommended techniques for handling the behaviors—for example, develop a regular schedule of physical activity during the day, engage in physical activity in the later afternoon or early evening to help ward off feeling of early sleepiness or drowsiness, and avoid rigorous exercise immediately before bedtime.
    • The type of support: (1) engage clients in an active discussion to select the physical activity they enjoy and afford performing, and to think through a plan or procedures to put in place to regularly perform the selected physical activity; (2) encourage clients to engage in the planned physical activity in daily life and monitor its impact on sleep; (3) review barriers and enablers, and generate or exchange ideas of what can be done to overcome barriers and reinforce enablers.

  2. Selecting the mode for delivering the active ingredients: This consists of specifying the manner in which the active ingredients, as operationalized into respective components, are to be given to the client population in the context of interest. This exercise is referred to as practical applications in the intervention mapping process. Practical applications are concerned with the way the techniques are translated for practical use or delivery to fit the context of the client target population (Dohnke et al., 2018; Kok et al., 2016; Mesters et al., 2018). As described in Chapter 2, mode of delivery is characterized by different media and formats, some of which may be more appropriate for the operationalization of particular active ingredients than others. Therefore, the selection of delivery modes is based on an understanding of the active ingredients and of the range of media and formats.

    The mode of delivery is carefully selected to: (1) be consistent with the nature of the active ingredient, as operationalized in specific content, activities, and treatment recommendations; and (2) facilitate the delivery of the active ingredients in a way that is efficient yet maintains integrity of the active ingredient. Selection of the delivery mode is informed, where available, by evidence of the effectiveness of different media and formats, in different contexts, as well as evidence of their acceptability to the client population of interest and feasibility of use in the context of interest.

    In the example of insomnia, education, as an active ingredient, can be delivered in the written medium and in the format of an online module that covers the information on the health behaviors, the pathway through which they interfere with sleep, and the treatment recommendations. This mode of delivery (online module) is considered efficient, reaching a large proportion of adults with insomnia, with minimal human (e.g. therapist time) and material (e.g. costs of printing) resource expenses, and burden on clients who can assess and review the module at their convenience (i.e. reduced burden associated with time and cost of transportation). However, the online mode of delivery may not be accessible to some clients such as those with low reading and computer skills, vision problems, limited understanding of the language in which the module is written, and those who do not have access to a computer at home. Further, it may not be helpful to persons with low motivation and/or low self‐confidence in the ability to carry out the treatment recommendations (Beall et al., 2014; Free et al., 2013; Murray, 2012). Lastly extant evidence, synthesized in systematic reviews, indicates that the effectiveness of online or web‐based modes for delivering interventions in achieving the desired changes in a range of health problems is rather limited. Specifically, van Straten et al. (2018) found that the effects of self‐help, web‐based modes of providing cognitive behavioral therapy on insomnia severity and other sleep indicators, were smaller than those of person‐dependent modes of delivery like group or individual sessions.

  3. Determining the optimal structure and intervention dose: Once the active ingredients are operationalized into components and the most appropriate and effective mode of delivery is selected, the optimal structure and dose should be determined for delivering the intervention, comprised of all ingredients. The structure has to do with the approach and sequence for providing the intervention. The decision to use a standardized or tailored approach for giving the intervention is made based on a number of factors discussed in Section 4.5 related to the design of tailored interventions. The nature, complexity (i.e. type and number of components), sequence, and mode of delivery guide the specification of the optimal dose. If available, empirical evidence obtained in studies that compared the effectiveness of different dose levels for the same intervention is used to further justify the specified dose.

In the example of insomnia, two active ingredients, education and support, are delineated. It is logical to estimate that (1) education can be offered in one, 90‐minute session; this session length provides ample time for the interventionist or therapist to present the detailed information at a pace suitable to clients who may vary in their ability or speed of grasping and processing the information, and for the clients to ask for clarification as needed; (2) support can be offered in four, 60‐minute sessions; having four sessions provides clients the opportunity to apply the treatment recommendations in their daily life, and to reflect on their impact on sleep in the time interval between sessions, as well as to discuss ways or strategies to overcome barriers and reinforce enablers in subsequent sessions; thus, the plan is for four sessions (one for education and three for support). The selection of this dose is supported by empirical evidence showing that behavioral therapy delivered in four sessions is effective in managing insomnia (van Straten et al., 2018).

Step 6 – Production of the Intervention Protocol and Materials

After delineating all intervention components that operationalize the active ingredients, mode of delivery, and optimal structure and dose, it is important to develop the intervention protocol and produce relevant intervention materials (Ball et al., 2017; Byrd et al., 2012). The intervention protocol organizes the sequence for delivering the components, and within each component, the order for relaying the content and for engaging clients in the planned activities; it also describes the specific procedures to be followed, and the human and material resources required for delivering the intervention (see Chapter 7). The intervention materials refer to those used by the therapist in delivering the intervention (e.g. slide presentation) or provided to clients as a reference for application of the treatment recommendations in daily life (e.g. booklet).


As introduced previously, there are three approaches for delineating the intervention’s active ingredients: theoretical, empirical, and experiential. The approaches can be used independently or in combination. The selection of one or more approaches is contingent on the availability of pertinent theory and evidence that describe the health problem as experienced by and therapies or techniques that are acceptable to the client population and context of interest.

4.2.1 Theoretical Approach Overview

The theoretical approach is applied where a middle range theory of the problem is available and has guided the generation of the theory of the problem. This approach involves a meticulous review of the propositions of the middle range theory for delineating the intervention’s active ingredients. The propositions of the theory point to aspects of the problem that are amenable to change (i.e. “where” we can intervene) and to therapies or techniques that are most appropriate to manage them (i.e. “what” we can do). Specifically, the theory indicates the nature of the techniques (what they are), which should correspond with the nature of the malleable aspects of the problem. It also explains the mechanism of action through which the techniques induce the desired changes, that is, why a causal link is expected between the application of the techniques and the changes leading to the prevention, management, or resolution of the problem (Davidoff et al., 2015; Dohnke et al., 2018; Kok et al., 2016; Mesters et al., 2018). In other words, the theory clarifies why and how the techniques work. Methods

The application of the theoretical approach begins with identifying middle range theories that explain the health problem and gaining an understanding of the theories’ propositions. To this end, an extensive search of the theoretical or conceptual literature is conducted. Publications (articles or textbooks) or other sources (e.g. unpublished documents) are selected that describe the propositions of the theories regarding techniques or therapies for addressing the problem. Information on the therapies or techniques is extracted and organized to highlight: the name or label of the technique (what they are called); the aspect(s) of the health problem they are posited to address (what do they target); the essential elements that characterize the techniques and that are hypothesized as responsible for their anticipated effects (what they consist of); and the pathway linking their application to the anticipated improvement in the problem experience. Information obtained from different publication or sources is analyzed qualitatively, using constant comparison, and synthesized to clarify what the techniques consist of and why/how they are expected to work.

Social cognitive theory is an example of middle range theory that identifies techniques to promote engagement in health behaviors. The theory proposes two main determinants of behaviors: beliefs or attitudes and self‐efficacy. It also delineates techniques for each determinant. Provision of knowledge about the behavior and its consequences is a technique recommended to enhance beliefs and attitudes. Persuasion (e.g. use of messages to promote clients’ awareness of the capabilities they have), mastery experiences (e.g. give opportunities for clients’ performance of the skills or behavior), and modeling (e.g. have clients watch a video showing that others have succeeded in changing the behavior) are techniques expected to strengthen self‐efficacy (e.g. Dalager et al., 2019; Direito et al., 2018).

Bartholomew et al. (2016) have compiled a taxonomy of theory‐based methods that can be used to delineate the active ingredients of interventions aimed to change behaviors. The methods are listed for a range of behavior determinants derived from different middle range theories of health behaviors. Strengths

The advantages of the theoretical approach relate to the delineation of the intervention’s active ingredients that are specific and consistent with the nature of the problem and its malleable aspects. The theory points to the aspects of the health problem that can be modified and to techniques to produce the desired changes. This maintains conceptual consistency or match between aspects of the problem and techniques, which enhances the specificity of the theory‐based interventions to the health problem and our understanding of what the active ingredients consists of and why or how they work. Understanding of the active ingredients is critical for their accurate operationalization into specific and nonspecific components of the intervention, which is required for the correct delivery of the intervention. Clarification of the intervention’s mechanisms of action has the potential to enhance its effectiveness. Effectiveness is improved because the factors contributing most significantly to the health problem are appropriately addressed and not inadvertently missed (Michie et al., 2008). Evidence indicates that theory‐based interventions are more effective than those whose design is not explicitly informed by theory, in producing beneficial outcomes (Glanz & Bishop, 2010; Murray, 2012; Painter et al., 2008; Prestwich et al., 2014). Limitations

The limitations of the theoretical approach for delineating the intervention’s active ingredients are related to the following points: (1) many middle range theories are descriptive and explanatory in that they provide conceptualizations of the health problem, but they fall short of suggesting how to modify the problem; in other words, the theories do not explicitly propose specific techniques to address the problem; (2) each middle range theory offers a unique conceptualization of the problem that specifies a particular set of determinants; reliance on one theory informs the design of interventions that target the respective determinants only and that may be of limited effectiveness because they do not address the most salient factors contributing to the problem as experienced by clients in the context of interest; and (3) some middle range theories may not have adequate and sufficient empirical support, raising concerns about their utility in informing the design of interventions (Lippke & Ziegelman, 2008).

4.2.2 Empirical Approach Overview

The empirical approach is the most frequently advocated and used in designing health interventions, consistent with the emphasis on evidence‐based practice. The approach is appropriate where evidence is available on the usefulness of interventions in addressing the health problem. The empirical approach relies on evidence to identify and select interventions. The evidence, derived or synthesized from intervention evaluation research, points to therapies or techniques that have been found effective in addressing specific aspects of the problem or the overall problem. Traditionally, empirical evidence is generated in studies that evaluated an intervention as a whole package. Reports of these studies highlight the results pertaining to the direct effects of the intervention on the health problem. The reports fall short of describing: (1) the intervention itself (e.g. DiRuffano et al., 2017; Hoffmann et al., 2014) making it difficult to identify its active ingredients; (2) the delivery of the intervention limiting the understanding of its specific and nonspecific components; and (3) the mechanism through which the intervention (including its specific and nonspecific components) affects the health problem constraining the ability to discern what aspects of the problem are addressed and how the desired changes are achieved (Abraham et al., 2014). Accordingly, the empirical approach assists in identifying interventions, more so than delineating their active ingredients. However, new methods have been used to compile evidence on the mechanisms underlying the intervention’s effects (e.g. realist review of the literature) and the active components comprising the intervention (e.g. component analysis). Traditional and new methods for reviewing empirical evidence are discussed next. Methods

General Review Process

The traditional and new methods for reviewing empirical evidence involve a search of the literature, critical analysis of the studies’ reports, and synthesis of the studies’ findings. The two types of methods share similar steps to: search the literature; select reports for review; and extract information. They differ in the analysis and synthesis of the extracted data and studies’ findings.

Literature Search

The search is done in various bibliographic databases (general and specific health‐related disciplines) for comprehensiveness. The search uses keywords that capture the health problem, its indicators, and each of its determinants judged as potentially modifiable. The keywords are combined with those reflecting possible interventions or techniques, including: (1) the name/label of generic intervention techniques (e.g. behavioral intervention) or specific therapies or methods (e.g. persuasion), which may have been suggested and/or actually used to address the modifiable aspects of the problem, or (2) words that are synonymous with the term “intervention” such as therapy, technique, method, care, treatment, service, and program. The search may be limited to a recent time period (e.g. past 10 years) to enhance the relevance of interventions to the current context.

Selection of Reports

The selection of reports is based on pre‐specified criteria. The criteria are related to: (1) the health problem or its aspects addressed by the intervention under evaluation; (2) the characteristics of the client population (e.g. age or gender) and context (e.g. rural areas) of interest; (3) the setting in which the intervention is delivered (e.g. client’s home); and (4) the study design (e.g. randomized clinical trials). It may be useful to specify broad criteria (in particular those related to study design) to enhance comprehensiveness of the evidence. In addition to reports of individual studies, those presenting findings of literature reviews (e.g. scoping, narrative, systematic) and/or describing a study protocol are selected because they provide information on the effectiveness and on the nature of the intervention and its components, respectively.

Data Extraction and Analysis

The information to extract from the selected reports of studies is presented in Table 4.1. It covers methodological and substantive characteristics of the study. Of importance in informing the delineation of the intervention’s active ingredients are details on the intervention related to its components, mode and dose of delivery, mechanism of action, and effectiveness in inducing the desired changes in aspects of the problem and in improving the experience of the problem. The analysis and synthesis of the extracted data vary by review methods.

Traditional Methods

The traditional review methods include scoping reviews, systematic reviews, and meta‐analyses. Scoping reviews involve a comprehensive search of the literature to identify the types of interventions that have been proposed, used, and/or found useful to address the health problem or its malleable aspects. For example, Guruge et al. (2017) conducted a scoping review to map out interventions addressing stigma of mental health. Systematic reviews and meta‐analyses focus on determining the extent to which interventions are effective in improving the health problem. In all types of reviews, content analysis of the selected reports is applied to identify qualitatively similar interventions. Codes are assigned to different categories of intervention (e.g. medication, education, behavioral).

TABLE 4.1 Information to extract from selected reports of empirical studies.

Category Examples
Methodological characteristics Type of design
Number and type of study groups
Time points for outcome assessment
Sample size
Quality of study
Intervention characteristics Goal of intervention
Active ingredients, or specific and nonspecific components
Content covered or activities in which clients or participants engage
Mode of delivery
Type and training of personnel or staff involved in intervention delivery
Hypothesized outcomes Type of outcomes
Measures used
Results Findings quantifying the intervention’s effects on the hypothesized outcomes
Additional findings related to:

  1. Fidelity with which the intervention is delivered
  2. Participants’ exposure (number of sessions attended), adherence (application of treatment recommendations), and satisfaction with the intervention
  3. Factors that influenced the delivery and/or outcomes of the intervention
  4. Mechanism underlying the intervention’s effects (either tested empirically or perceived by participants and/or staff)
  5. Unexpected outcomes

In systematic reviews, vote counting is used to synthesize the evidence on the interventions’ effects. This consists of reviewing the findings of each study to determine if the interventions produce: no significant effects; significant effects in the hypothesized direction (i.e. clients or participants exposed to the intervention report improvement in the problem); or significant effects in the non‐hypothesized direction (i.e. participants exposed to the intervention reported worsening in the problem). Interventions are considered effective if they produce significant effects in the hypothesized direction in most (more than 50%) studies included in the review (Hong et al., 2017).

In meta‐analyses, statistical methods are applied to estimate the effect size, which quantifies the magnitude of the intervention effect on each outcome examined in each study included in the review. The extent of variability in the effect sizes is examined across studies. Low variability suggests that the intervention’s effects on the outcomes are consistent; in this case, the effect sizes are aggregated across studies, taking sample size into account, and yielding an average point estimate (with confidence interval) of the intervention’s effects. High variability prompts the investigation of possible causes of the heterogeneity in the estimated effect sizes. Possible causes are characteristics of the client population (e.g. gender, age), the intervention (e.g. components, mode or dose of delivery), the context in which the intervention is delivered (e.g. personnel providing it, setting), or the study (e.g. design, outcome measure). Advanced statistical tests (e.g. meta‐regression) are used to relate the effect sizes to possible causes (Hong et al., 2017; Paré et al., 2015). The findings may point to variability in the effectiveness of different interventions in different client population and contexts. Such empirical evidence is most informative in selecting interventions as it indicates the intervention or the components that are most successful in the same or similar client population and context of interest.

New Methods

New methods for reviewing empirical evidence include mixed methods reviews or syntheses that aim to delineate the interventions’ active ingredients and mechanism of action. To address the first aim, intervention component analysis is proposed and illustrated in the Distillation and Matching Model (Chorpita et al., 2005). The intervention component analysis consists of several steps: (1) review relevant theory‐based interventions to identify their active ingredients and their operationalization into components and techniques; (2) develop a guideline for coding them, where the guideline specifies the name of the components or techniques and describes what they entail; (3) search and select empirical studies that evaluated the interventions, components, or techniques; (4) extract descriptions of the interventions and results of their evaluation; (5) review the extracted descriptions of interventions and code for the presence of components or techniques; (6) generate matrices that summarize the coded component or techniques and the results of evaluation studies; and (7) analyze the data, using appropriate algorithms or statistical tests to explore patterns in the matrices that indicate which combination of theoretically derived components or techniques is associated with beneficial outcomes. A variant of this method was applied by Fox et al. (2013) to identify the most effective components of the acute care for elder (ACE) model.

To address the second aim, mixed methods review and synthesis are recommended. The review focuses on delineating the interventions’ mechanism of action. It involves selection and review of studies that evaluated the process of implementing and of the outcomes of interventions. Process evaluation (see Chapter 13) involves the investigation of the fidelity with which the intervention is delivered, of contextual factors affecting the delivery and effectiveness of the intervention, and of clients’ perception of the intervention and its impact. Outcome evaluation (see Chapters 14 and 15) is concerned with examining the effectiveness of the intervention in inducing the desired changes in aspects of the health problem (referred to as immediate and intermediate outcomes) and improving the experience of the health problem and preventing its consequences (posited as ultimate outcomes).

The quantitative and qualitative findings pertaining to process and outcome are analyzed separately or concurrently, and integrated to delineate the pathway linking the intervention or its components and techniques to the immediate and intermediate (i.e. desired changes) and the improvement in the ultimate outcomes (i.e. health problem experience) (Edwards & Kaimal, 2016; Gough, 2013; Snilstveit et al., 2012; White, 2018). Examples of mixed methods review are framework synthesis (Carroll et al., 2013) and realist reviews (Pawson et al., 2005). Both involve (1) engagement in an initial exercise to clarify the problem and to model the intervention’s mechanism of action and contextual factors that may affect the delivery, mechanism of action, and/or outcomes of the intervention; this initial model is represented in a configuration that links context, mechanism, and outcome of the intervention; (2) review of the theoretical literature and empirical (quantitative and qualitative) evidence and extraction of data reflective of contextual factors, intervention components or techniques, desired changes and effectiveness in addressing the health problem; (3) coding of the extracted data relative to configuration of context, mechanism, and outcome; and (4) analysis and integration of the theoretical and empirical evidence to determine the adequacy or the need to revise the initial model. The application of the realist review is illustrated in the work of Robert et al. (2017). Strengths

The empirical approach has the advantage of identifying interventions that have been implemented and evaluated. The evidence suggests that the interventions are feasible and effective in preventing, managing, or resolving the health problem, in different client populations and contexts. Limitations

Extant empirical evidence has limitations: (1) the interventions are often poorly or briefly described, which creates difficulty in appropriately coding them, and the potential of lumping variant interventions in the same category; variability within categories may yield underestimated effects for the categorized interventions; (2) there is a rather small number of studies that evaluated the effects of different active ingredients or components comprising an intervention, the fidelity of intervention delivery, and the context and mechanism underlying the intervention’s effects; yet this evidence is useful to delineate the intervention’s active ingredients and to select the components that are most effective in addressing the potentially modifiable aspects of the health problem; (3) there is growing acknowledgement of publication bias, which threatens the validity of the synthesized empirical evidence; that is, there is a tendency to selectively report positive outcomes (Chan et al., 2014) and publish reports of studies with “statistically significant” effects; when averaged, these effects yield overestimated intervention’s effects (van Assen et al., 2015).

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Nov 28, 2021 | Posted by in NURSING | Comments Off on 4: Designing Interventions
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