CHAPTER 2. THEORETICAL BACKGROUND
2.3 Process Model Linking Trust to Adherence
Although researchers have examined the relationship between trust, self-efficacy, and outcome expectations in non-health care settings (Ergeneli, Arı, & Metin, 2007; Hsu, Ju, Yen,
& Chang, 2007; Siwatu, 2007), a look at the health care literature reveals a lack of research in this area. By definition, trust reflects patient’s expectations (Hall, 2006). Because published studies find that most placebo effects are linked to expectancies (Kirsch, 2004;
Stewart-Williams & Podd, 2004), trust is suggested to affect a patient’s therapeutic response by mechanisms similar to the action of placebos (Basmajian, 1999; Hall et al., 2001).
According to Bandura (1997), expectancies are of two types: self-efficacy expectations and outcome expectations. Crow and colleagues (1999) thus applied self-efficacy and outcome expectations to access the process of expectancy in placebo effects. They also proposed the patient-physician relationship as a critical determinant of these two constructs. Following this
approach, we developed a process model intended to explain the mechanisms through which trust influences patient adherence.
2.3.1. Trust, self-efficacy expectations, and outcome expectations regarding adherence
The dominant explanation for trust and cooperative behavior in previous research hinges on the positive expectations of behavior of another party and outcomes in interaction
(Bhattacharya & Devinney, 1998; Gambetta, 1988). According to Bhattacharya, trust links to expectancy of positive outcomes. Trust may shape the outcomes that individuals expect their cooperative efforts to produce. Those of high trust thus expect their efforts to realize favorable outcomes. Because physicians have authority to make treatment decisions that have
significant impact on patients’ treatment outcomes, perceptions about the trustworthiness of the physician become important. When patients believe their physicians are trustworthy, they are more likely to expect more results from the physicians’ recommended health behaviors or treatment plans. For trusting patients, favorable outcomes can be increased through
cooperation or adherence. However, an additional cognitive component of motivation, self-efficacy expectations arising from patient-physician encounters, may also predict this relationship.
According to a dominant paradigm in research on motivation and effort are a function of not only the outcomes individuals anticipate will result from their action but also their
efficacy expectations (Bandura, 1986; Vroom, 1967). Predictions of cooperative behavior resulting from trust have relied solely on the first aspect of a general motivation model, anticipated outcomes in interaction, and have neglected the second aspect, efficacy. Although some studies have proposed that patient-physician relationships are a key determinant of patient’s perceived self-efficacy (Ohya et al., 2001; Zachariae, Pedersen, Jensen, Ehrnrooth,
Rossen, & von der Maase, 2003), research to date has not evaluated the relationship between trust and patients’ perceived self-efficacy.
Self-efficacy expectations, defined as one’s belief in the ability to perform a specific behavior or set of behaviors required to yield a favorable outcome (Bandura, 1977), reflects context-specific evaluations of the capabilities to mobilize motivation, cognitive resources and courses of action needed to exercise control over task demands. In this study, the term self-efficacy refers to the patient’s belief in his/her ability to carry out specific self-care behaviors and keep the disease under control. How trust influences a patient’s sense of efficacy regarding adherence may operate through a number of means. Our rationale for expecting this relationship is based on Bandura’s self-efficacy theory, which suggests a number of antecedents of self-efficacy expectations (Bandura, 1986, 1997). First, trust frequently results from one’s positive experience over time. Reliability in previous interactions with the trustor give rise to positive expectations about the future interactions (Rousseau et al., 1998). Patients trust their physicians and engage in health behaviors that will provide them with as much success as achieved in previous treatments. These positive
experiences in patient-physician encounters over time should be self-reinforcing and should strengthen expectations about patients’ ability to perform recommended health behaviors.
Because mastery of experience is the most influential source of efficacy information (Bandura, 1986), patients’ sense of efficacy is likely to be shaped by previous successes in trusting settings. Second, exhortation and suggestion by credible persons can influence an individual’s sense of efficacy (Bandura, 1986). Such mechanism may particularly influence self-efficacy approvals from a trusted health professional. For example, self-efficacy for disease
management can be enhanced by health professional support and genuine persuasion in the context of a trusting relationship (Howells, 2002). Arising through support and realistic encouragement, a trusted physician’s persuasion can contribute to patients’ health behaviors
by enhancing self-efficacy and motivating patients to overcome the impediments to adherence.
Third, higher levels of anxiety serve as negative feedback that can erode self-confidence and performance, especially for complex tasks (Bandura, 1997). Patients having a low level of trust are likely to be psychologically distressed when the physician has power over important treatment decisions. In contrast, patients are likely to feel safer and less anxious about the physician making these decisions when they believe the physician is trustworthy (Hall et al., 2001). In this regard, trust may reduce patients’ emotional distress and thus increase cognitive appraisal of self-efficacy.
By reducing uncertainty and decreasing efforts to copiously account for all potential contingencies, trust results in greater control over behavior (Zand, 1972). In contrast, perceptions of untrustworthiness increase an individual’s awareness of existing conflicts of interest and encourage them to view the relationship as less cooperative (Mishra, 1996). For example, medical mistrust was found to be linked to lower patient self-efficacy (Maly, Stein, Umezawa, Leake, & Anglin, 2008)
Extending the work of previous research, we expect that trusting patients will have high levels not only of outcome expectations but also of self-efficacy expectations.
2.3.2. Self-efficacy and outcome expectations as mediators leading to adherence
In general, self-efficacy and outcome expectations, which cognitive control of behavior is based on, are highly correlated with patient adherence to treatment (Iannotti et al., 2006; Kerr et al., 2005; Resnick, Wehren, & Orwig, 2003).The stronger the perceived self-efficacy and outcome expectations, the higher the goals of health behavior people set for themselves and the firmer their commitment to them (Bandura, 2004). For example, a study of motivation to exercise in stroke survivors found that self-efficacy and outcome expectations are key
determinants of adherence to both initiating and maintaining exercise programs (Shaughnessy, Resnick, & Macko, 2006). Because individuals’ self-efficacy expectations will guide their choice of activities, preferences for tasks, and persistence in working on a task, such beliefs can influence patient adherence in the face of different obstacles. In addition, a patient may have high self-efficacy for adhering to recommendations to treat disease, but if he does not believe the advised medication and behavior will improve health (i.e., outcome expectations), then adherence is unlikely. Accordingly, both self-efficacy and outcome expectations are influential in the adoption and maintenance of health behaviors recommended by physicians.
In sum, when individuals believe another party is trustworthy, they will have more positive expectations and be more comfortable engaging in cooperative behaviors that may put them at risk (Lewicki, McAllister, & Bies, 1998; Schoorman, Mayer, & Davis, 2007). For instance, trust in the physician was found to be one of the strongest predictors of patients’
decisions to enroll in a study of a new treatment of cancer (Penman et al., 1984). Rosenbaum (1990) posited that the patient-physician relationship may influence the process-regulating cognition that underlies adherence to treatment. Therefore, we advanced the following hypotheses to test the effect of trust in the physician, mediated through self-efficacy and outcome expectations, on patient adherence to recommendations.
Hypothesis 2a: Self-efficacy expectations will mediate the positive effects of trust in the physician on patient adherence.
Hypothesis 2b: Outcome expectations will mediate the positive effects of trust in the physician on patient adherence.