We found that oftentimes when investigators study attitudes, they do not define this construct. As Martinez et al. observe, implementation science could benefit from “carefully defining” a construct of interest, “ideally based on existing theory or available definitions” [
2]. We recommend adopting the standardized definition of an attitude that is widely used in social psychology. An explicit definition of attitude can inform procedures for measuring this construct [
24]. This standard definition would distinguish attitudes from other constructs with which they often are conflated, including willingness, intention, and self-efficacy. Definitions would also help clarify whether investigators intend to distinguish attitudes from other terms, such as “acceptability,” “appropriateness,” and “barriers and facilitators.” Without clear definitions, there are many opportunities for investigators to lack agreement on the meaning of constructs. For example, when developing a “Theoretical Domains Framework,” participants who “possessed a good understanding of behaviour change theory” were asked to interpret the meaning of attitudes and various other terms that were not defined. They found different ways to interpret the meaning of these terms and their theoretical relationship to each other [
43].
In the studies explored in the present review, authors rarely explain how attitudes were measured. When they do, their accounts suggest that attitudes were measured in unrelated ways among different studies. Research in social psychology has shown that, with fundamentally different approaches to measuring attitudes, “a study can lead to apparently conflicting results and different conclusions concerning the relations between attitudes and other variables” [
24]. Implementation science has the opportunity to apply validated, standardized measures of attitudes with guidance tailored specifically to implementation researchers [
14].
In particular, future studies can measure attitudes towards using a particular EBP in a specified context and then test the degree to which attitudes explain variance in a population’s strength of intention to perform that behavior [
61]. As documented by a systematic review of implementation science, behaviors are rarely specified clearly [
62]. In turn, Presseau et al. warned, “Despite half a century of guidance on behaviour specification, research is frequently published in which the behaviour is poorly specified” [
23]. Presseau et al. have argued that implementation science could improve the measurement of theoretical constructs by specifying the behavior of interest. This guidance can be applied specifically to attitude measurement. The present review found that studies measured attitudes towards general categories, such as “new practices” or “evidence-based practices” rather than a specific behavior.
The conceptual and methodological problems documented by this review are similar to those that the field of psychology faced in the early part of the twentieth century, as encapsulated by the following statement by Fishbein and Ajzen: “In addition to a lack of agreement on the definition of attitude, different noncorrelated operations can be found for the same concept, and the identical operation is often given different conceptual labels” [
15]. They added that, as a result of this conceptual and methodological neglect, attitude research has largely been “noncumulative and has failed to produce a systematically integrated body of knowledge.” Without standardized approaches, it is difficult for the research to develop a common scientific language, compare or pool findings across studies, or develop theories that can establish causal mechanisms of implementation [
2,
63].
The utility of causal models
There is a great deal of empirical evidence about the role of attitudes based on psychological studies of many different behaviors. The lessons learned from psychological research about behavioral prediction and change are directly applicable to implementation research. Implementation research examines behavior within organizations. The discipline of psychology includes organizational psychology, which has the same goal as implementation science [
64,
65]. Both fields are concerned with identifying the determinants of behavior. When citing Eccles et al. [
66], Presseau et al. [
59] summarize: “Behavioural science has systematically operationalized theories concerning determinants of behaviour and how they are associated with each other. This may be useful for understanding the mechanisms underlying implementation interventions designed to change clinicians’ behaviour.” Godin et al. [
35] also observe: “The problem of understanding why healthcare professionals do or do not implement research findings can be viewed as similar to finding out why people in general do or do not adopt a given behaviour such as health-related habits.” They stress, “This has been extensively investigated, and social psychological theories have already demonstrated their value.” In contrast to causal models, “frameworks” (such as the Theoretical Domains Frameworks) rely on intuition to identify the domains and constructs that seem to be “the most suitable.” Such frameworks do not identify which domains or constructs have causal relationships with one another. Well-tested models, on the other hand, represent the results of empirical tests (spanning many decades) that demonstrate the predictive validity of specific constructs and their causal pathways, which allow studies to identify the mechanisms of behavior change and design interventions to target them.
Theories that have demonstrated predictive validity, such as the Theory of Planned Behavior [
67], Unified Theory of Behavior [
68], and the Integrated Model [
69], are based on evidence that attitudes can influence behavioral intention. These theories also posit that, in addition to attitudes, perceived behavioral control (or self-efficacy) and subjective norms can influence behavioral intention. This proposition could be tested within implementation research to better understand the degree to which attitudes explain variance in a study population’s motivation to implement a particular EBP. Implementation science can also test which variables influence attitudes. By designing studies to evaluate theorized relationships between constructs in causal models, the results can inform the development of implementation strategies. Implementation strategies are likely to be effective and efficient if they target the malleable constructs that predict outcomes [
1].
When testing a causal model, it is important to empirically establish the degree to which attitudes contribute, since the role attitudes play will vary depending on the population and specific behavior of interest. When attitudes explain a substantial proportion of variance, intervention strategies can be developed to change attitudes — which are malleable — and potentially increase EBP uptake. For example, in many studies, attitudes drive intention to a greater extent than do subjective norms [
18‐
20]. In other cases, subjective norms are more influential than attitudes [
13,
70,
71]. Depending on which variables are predicting intention to use an EBP, implementation strategies can be designed to target the most influential determinant of intention, and strategies that do not may be less effective and efficient [
70,
71].
When considering the limitations of the current study, it is important to note that the articles reviewed may not be representative of other implementation studies. Indeed, we purposefully selected a sample of articles that empirically studied mediators and moderators. As documented by McIntyre, implementation science has a high proportion of articles that express interest in studying theory-based constructs, such as attitudes, but forgo an empirical assessment. In a secondary analyses of the articles included in McIntyre’s review, we found that 4% (4/123) provided information on attitude measurement, and doing so was more common in our primary sample. Given the breadth of research in implementation science, this review is not intended to represent the wide-ranging variety of studies that could be sampled.
In addition, the present review was limited to recent articles. Given that our results are based on recent publications, the results may be less relevant to older implementation research. For example, a review by Godin et al. [
35] identifies several articles that mention attitudes but these articles are not included in our sample. Future research could investigate older studies in implementation science to determine if attitude theory and measurement has improved over time.