2.1. Overconsumption of Health Care and Patient Moral Hazard
There have been numerous attempts to estimate the scale of overuse of medical care, although they have not always brought the expected results. The limitations of the initial efforts mainly resulted from the difficulties in defining the concepts and, consequently, developing a methodological approach. Chassin and Galvin [
13] (1998) define overuse as “the provision of medical services for which the potential for harm exceeds the potential for benefit”. The mere measurement of the benefits and harms of using medical services is a controversial issue, mainly due to incomplete data and a missing typology of services [
14,
15].
One cautious estimate made in the U.S. and based on direct measurements across individual services shows that overuse rates are between 6% and 8% of total health-care expenditure [
16]. Other studies indicate that overuse losses in the U.S. are as high as 29% [
17]. There have been reports of even higher percentages, although those results are only subject to limited comparison. Although overuse is a global problem, most research concentrates on high-income countries, with negligibly little interest in low and middle-income countries [
15]. Brownlee et al. [
15] present a number of doubts concerning both the direct and indirect methods for measuring overconsumption. At the same time, they state that such research is necessary because overuse may lead to a physical, mental, and financial harm to patients and contribute to the excessive use of the resources of the health and social care systems in both high-income and low- and middle-income countries. They point to the global scope of the phenomenon covering most medical specializations (hence, overtreatment, over-testing, over-diagnosis, overuse of medication, overuse of screening tests, etc.). Other authors point out that controlling overuse of health care may have positive impact on cost reduction and quality improvements at the same time by sparing patients the unnecessary risk that attends to inappropriate health care [
13].
One special type of overuse referred to as moral hazard. It is commonly understood as an excessive expenditure due to eligibility for insurance benefits [
18]. According to economists, moral hazard is perceived to be any misallocation of resources that occurs when risks are insured with only normal insurance contracts. More specifically, it is defined as health insurance bearers’ inclination to change their behavior in a way that increases the risk of loss for the insurer. According to Zweifel and Manning [
19], there are two categories of moral hazard behaviors in the context of health insurance: ex ante behaviors, where the risk of loss grows prior to a medical event with individuals engaging in higher-risk activities, thus increasing the likelihood of an event causing a loss, and ex post behaviors with individuals using increasing levels of health care following the event [
20]. Folland et al. [
21] has found that moral hazard refers to the increasing use of services, while the marginal costs of medical services are declining.
Overconsumption of medical services that are covered by insurance, either public or purchased privately, can lead to multiple adverse effects, including an increase in the costs of medical services and a reduced availability of services for patients in actual need. In an effort to limit the overall costs of overuse of medical services, factors with the potential to help constrain such patient behavior must be identified. Research into overuse reported in the literature primarily makes use of macroeconomic analyses and focuses on attempts at estimating its size [
22]. Other authors also seek to determine the relationship between co-payment schemes and the level of demand for medical services. The results reported confirm that moral hazard can be controlled through demand management, e.g., through the introduction of co-payment systems [
23,
24].
Additionally, Blomqvist [
25] notes that, while co-payment reduces moral hazard by increasing the efficiency of health care use, it may limit the consumption of medical services, which in turn may contribute to an increased risk of disease and poorer patient welfare. Clearly, however, little research has been devoted to identifying determinants that either support or inhibit excessive consumption of medical services. For certain, though, such factors typically include the price and the type of the potentially overused medical service [
26]. The studies carried out for the U.S. by Konetzka et al. [
27] indicate that elderly patients overuse home care if it is funded by insurance. Zweifel and Manning [
19] have attempted to identify the stimuli (on the part of patients) that may significantly contribute to the likelihood of moral hazard, among them, the patients’ age. Moreover, other studies indicate that patients’ previous experiences affect the chances of developing a tendency to overconsume medical services. At the same time, research performed in the USA shows that the overuse of hospital stays is much more likely than, for example, drug overconsumption [
28]. There is definitely a need for further studies that would expand our knowledge of the factors that determine the overuse of medical services.
2.2. Patient Satisfaction and Patient Adherence
The health system is a professional service sector where the concept of customer satisfaction is also applicable. The most common understanding of this concept refers to a subjective evaluation of services received by a customer [
29]. Patient satisfaction with the medical services has been defined a patients’ overall evaluation of the performance of a service offering after experiencing it [
30]. It can be treated as an essential evaluating tool for health care delivery [
31], as well as an important quality indicator of health care [
32]. Patient satisfaction reflects the gap between the expected level of health care and the actual experience of the medical encounter, perceived by the patient.
It has been proved that patient satisfaction with past outcomes positively impact social/general trust in physicians as a professional community [
33]. Moreover, many authors point at a significant positive relation between overall satisfaction with the health care and overall communication behaviors [
34,
35], but there is no extensive evidence how these attributes of the patient-doctor relationship impact patient consumption patterns in health systems.
World Health Organization interprets patient adherence as the extent to which a person’s behavior (such as taking medication, modifying lifestyle, following a diet) corresponds with agreed recommendations from a health care professional [
36]. In the literature this term as used as an alternative to compliance [
37]. Non-adherence or noncompliance is, thus, perceived as a negative behavior of a person facing a medical problem. Non-adherence to drug therapy or general to medical treatment seems to be a common problem in health systems. According to different sources, the adherence rate for long-term medication ranged from 33% to 94%, and the compliance rate in long-term therapy tend to reach at the most 50%, no matter the setting or illness [
38]. This phenomenon has been recorded both in developed, as well as in developing, countries. Poor compliance to medical treatment has a negative impact on health indicators, such as morbidity and mortality rates [
36]. It can be also associated with lower treatment efficacy, higher hospitalization rates, and higher health care costs [
39].
It has been investigated that patients’ motivation to adhere to medical treatment is positively related to their understanding of the health condition and the treatment itself, together with their faith in the physician [
40]. It can, therefore, be assumed that the non-adherence can be associated with poor understanding and beliefs about the treatment and with weak trust in a doctor. The first correlation have been shown in previous studies [
41], but the second one still needs more recognition.
2.3. Trust in Health Care
Trust, with its definitions attempted by different disciplines ranging from psychology to management, is an extraordinarily complex construct. It is perceived as an important feature of any relationship, both on a micro- and macroscale. The concept of trust has become especially meaningful in the service sectors of the economy that are purely focused on relational links, such as health care.
Trust can be viewed from multiple perspectives. In social sciences, trust is understood as an infinite process [
42] and the foundation of social interactions [
43]. It is believed to be a valuable resource for systems, organizations and interpersonal relationships [
44]. According to Hardin [
45], trust is an alternative to credibility which, ensured by various social solutions, institutions, or standards, allows one to take actions based on confidence. Putman [
46] believes that trust is an element of social capital that “
refers to features of a social organization such as trust, norms and networks that can improve the efficiency of society by facilitating coordinated actions”. In economics, trust is perceived as an “informal norm” that reduces the costs of transactions that supervise the conclusion of contracts, the enforcement of formal agreements and the settlement of disputes [
47]. According to the behavioral approach prevailing in psychology, trust typically means “holding a positive perception about the actions of an individual or an organization” [
48]. It is commonly described as the willingness to rely on a partner in whom one has confidence [
49]. Trust allows us to believe that others will behave as they are expected to, whether on a one-off basis or in a set of situations. Although trust may be developed through actual experience, it is often subjective and based as much on interpretation as on facts [
48].
Any discussion about trust is hindered by the wide range of available classifications of this relational aspect. Comprehensive reviews of these classifications have been prepared by Jabłoński and Jabłoński [
50] and OECD [
48]. In the present paper, the focus is only on those that can be applied to health care. And so, as regards trust in medical professionals there are two closely related concepts identified: general trust people have in physicians as a whole, on the one hand; and interpersonal trust found in a relationship with the particular physician, on the other [
51]. Theoretically, patients’ general trust in physicians contributes to inducing their interpersonal trust in a newly-acquainted doctor and to maintaining that trust as the interactions develop [
52]. Based on the social theories of Giddens and Luhmann, it has been shown that these two types of trust are engaged in an interaction resembling a complex helix [
53]. Studies have shown that general trust in doctors correlates with trust in the particular physician, thus encouraging satisfaction with the care received, better medical adherence [
51,
54] and fulfillment of medical needs [
9]. Moreover, interpersonal trust may contribute to the patients introducing and maintaining a self-care management regime, and adhering to treatment [
55,
56]. It has also been proven empirically that higher levels of trust in medical professionals have a positive impact on patient outcomes, e.g., in such areas as glycemic or blood pressure control [
57], which may entail lower health-care costs [
3]. In turn, a patient’s mistrust leads to them adopting undesirable behaviors and attitudes, resulting in poor satisfaction with the care received [
58] and a reduced degree of interaction with the health system [
59]. Patients who do not follow medical advice and fail to adhere may need extra treatment in the future, which translates into medical expenditure escalation on the macroscale. Thus, mistrust can potentially increase medical expenditure and lead to inefficient resource allocation [
60].
The literature also features analyses of the concept of public trust. This form of trust is one that a person or a group of persons place in a system or a societal institution, such as a health system [
10]. Similarly to general trust in medical professionals, public trust in a health system and an individual’s interpersonal trust may be mutually supportive [
7]. Public trust can determine how patients develop their interactions with health care providers, whereas the experience they derive from contacts with health care institutions and their representatives can in turn impact on public trust. Public trust can be, thus, associated with how patients and the general public perceive the health system and its ability to deliver services and, eventually, to meet its goals [
1]. Moreover, it can provide a significant indicator of the level of support for the health system as a whole [
1]. Public trust, also referred to as social trust, informs interpersonal trust [
61]. It can be influenced not only by the past experiences of a particular patient or their generalized social confidence in the public institutions but also by the experiences of others and by the mass media [
62].
Public trust is of critical importance in a service encounter, especially in the case of interactive services, such as health care. It determines possible future behaviors of patients and, therefore, can be created as a key asset of the medical profession and the health system as a whole. Based on the findings reported in the literature of the English-speaking world that relate mostly to developed countries [
63,
64] or to the race minorities found within them [
65,
66], public trust can be claimed to impact on an array of health behaviors. It can be assumed that higher trust levels are typically associated with positive behaviors. In the health care context, it may be assumed that public trust creates a higher level of patient satisfaction and leads to better compliance with medical treatment, which in turn ultimately influences the level of consumption of health-care services [
67]. On the other hand, a lack of trust (mistrust) entails poor clinical relationships that exhibit less continuity, poorer adherence to the doctors’ recommendations, and a reduced degree of patient-physician interaction [
66].
Public trust is a multidimensional concept. Within the research context, it is usually explored through several dimensions that relate to prioritizing patients’ interests, care quality, the service providers’ expertise, a patient-centered focus of health care, the effects of health system policies, access to health-care products and services, and information and communication provision [
1,
63,
64,
68,
69]. These dimensions reflect the diverse considerations on how public trust should be understood and measured, going far beyond the technical competences of medical professionals. These aspects have also been accommodated within the scale designed as part of our study to measure public trust.
While interpersonal trust has been studied extensively, social trust in the health system, especially for countries in transition, has gained far less scientific attention. The existing literature presents findings concerning predictors of trust in health systems [
70], antecedents of patient trust in health-care insurance [
71], general trust in the medical profession [
51], fiduciary trust in physicians and its outcomes [
72]. As there is limited research on public trust and health care use in the systems in transition, it is currently unclear how these two constructs interrelate and what the roles of patient satisfaction and medical noncompliance are. In our study we are going to fill in this gap. Therefore, this study is specifically concerned with the concepts of patient satisfaction and patient non-adherence as mediators in shaping overconsumption in health systems. Our work is based on the key terms discussed in
Section 2.1,
Section 2.2 and
Section 2.3.
Table 1 shows a brief summary of the presented concepts.