Social theorists have long understood that diffused trust in broad social and professional systems is critical to the functioning of modern, complex societies (Luhmann 1973
; Barber 1983
; Zucker 1986
; Fukuyama 1995
). Stronger system-level trust facilitates the formation of vulnerable interpersonal relationships without extensive knowledge about individual personal characteristics. This form of trust has assumed tremendous significance in the medical policy arena, owing in part to the complexities of medical care delivery, and changes in health care financing, which require patients frequently to form new treatment relationships with providers they do not know (Little and Fearnside 1997
; Mechanic 1996
). It is this more generalized form of trust, however, that may be a greatest risk. Frequent observations that trust is diminishing in physicians usually refer to trust at a broader system level rather than trust in a specific known physician (Blendon and Benson 2001
; Pescosolido, Tuch, and Martin 2001
; Schlesinger 2002).
To facilitate more rigorous study of these issues, we developed a multidimensional conceptual model of trust, which guided our development and validation of an 11-item scale to measure patients' trust in physicians in general. This is the first reported multi-item scale to measure trust in the medical profession. Previous measures of trust in the medical profession have consisted of nonvalidated single-item measures. Validated, multi-item scales assessing various aspects of the medical institutions and health care delivery systems have focused on satisfaction rather than trust. While satisfaction is undeniably an important attribute and is related to trust, trust is a distinct attribute and may prove to be a fundamental force in shaping other attitudes, behaviors, and outcomes. A general trust scale could be a useful tool for deepening our understanding of the basis for trust, measuring the performance of health care systems and institutions, and assessing the impact of organizational, operational, and regulatory initiatives.
The instrument presented here covers all the important domains of trust except confidentiality, and has good psychometric properties when used in both a general, nationally representative population of people with sources of payment and established treatment relationships. The instrument has good reliability and response patterns. Consistent with findings from studies of trust in individual physicians (Kao, Green, Zaslavski et al. 1998
; Thom et al. 1999
; Safran et al. 1998
; Hall, Zheng et al. 2002
), factor analyses showed that general trust is unidimensional, contrary to our starting assumption and somewhat in contrast with trust in other settings (interpersonal and business) (Mishra and Spreitzer 1998
; Johnson-George and Swap 1982
; Larzelere and Huston 1980
; Corazzini 1977
). This means that people do not appear to distinguish trust in the medical profession among the dimensions of fidelity, competence, and honesty. This unidimensional conceptual model is further confirmed by the fact that the two items with the highest correlations to the overall scale (.67 and .65) are items 13 and 25, which are the two most global items and the only two items that use the word “trust” (“you completely trust doctors' decisions about which medical treatments are best” and “all in all, you have complete trust in doctors”).
It is notable, however, that items measuring the domain of confidentiality were not retained in the final scale. The confidentiality items that were pilot tested all performed too poorly to be included in the national survey except for item 19, and it was not included in the final scale because it had among the lowest item-to-scale correlations (.37). Also, this confidentiality item had the highest item mean (3.54) of all tested items, even though it is negatively worded, which tends to produce lower means due to acquiescence bias (Ware 1978
). (The means for the other nine negative items ranged from 2.44–3.10 and averaged 2.75.) This indicates that most of our subjects were not concerned about how doctors in general protect confidentiality and the variation in concern that exists is poorly correlated with responses to other trust questions. This finding is consistent with findings from studies of trust in individual physicians (Mechanic and Meyer 2000
; Kao, Green, Davis et al. 1998
; Thom et al. 1999
; Hall, Zheng et al. 2001
). However, this may not bear out in minority groups or in specialized populations such as HIV patients or patients with mental illness or with some genetic conditions.
General trust exhibits a strong positive association with satisfaction, trust in one's physician, and following doctors' recommendations, and a strong negative association with prior disputes with physicians, having sought second opinions, and having changed physicians. These correlations are all consistent with our conceptual model. It is important to note, however, that these validation measures are self-reported attitudes, events, and predicted behaviors. Objective measures in a longitudinal study design would provide a more rigorous validation.
In exploratory analyses, we failed to find any relationship between trust and various demographic characteristics, other than age. This is especially notable for race and ethnicity. Others report that members of minority groups have lower levels of trust in the medical profession (LaVeist, Nickerson, and Bowie 2000
; Gamble 1997
). Our failure to confirm this may indicate (consistent with Pescosolido, Tuch, and Martin 2001
) that distrust in the personal characteristics of physicians is not as great among disadvantaged groups as is often assumed, or this may be due to a deficiency in the scale or limitations in our survey and sampling methods. For instance, lower general trust could be masked by a reluctance to give critical responses, which is discussed more below. Also, although our piloting and focus group samples included members from minority groups, items were not separately assessed within minority groups, and our sampling of minority groups in the general survey was not adequate to explore racial differences in trust. It is likely that trust-related concerns among some minority groups are sufficiently different that psychometric development on a general population would fail to include some items of special relevance for minorities (for instance, item 7 relating to conflicts of interest in research was not retained). Future research should address this important concern. Similarly, because this study was based on a general population mostly in good health, the scale may perform differently in populations with particular health conditions of interest, such as mental illness, chronic disease, or life-threatening acute conditions.
We compared general trust with trust in specific physicians to determine their similarities and differences. When general and interpersonal trust are measured with parallel items in the same population, interpersonal trust is approximately one-fourth higher on average (42.7 versus 33.5). There are several different possible explanations for this disparity. First, it has been observed in other fields, such as politics, that people typically have stronger trust in individuals than in professional systems (Blendon et al. 1997
). The personalization that occurs when an individual relationship is formed may give an immediate boost to the level of trust that one has in the general profession. Higher interpersonal trust also could reflect the fact that people are generally inclined to have an optimistic view of themselves and their relations. As in Garrison Keillor's fictional Lake Woebegone, most everyone's doctor is better than average. This general tendency may be heightened in medicine by the need to resolve the cognitive dissonance that would otherwise exist if people believed, in a situation with such great anxiety and vulnerability, that their physician is not better than average (Hall and Dornan 1988
Similarly, but somewhat differently, Hays and Ware (1986)
demonstrate that higher response rates for provider-specific questions indicate a form of social desirability bias (tending to skew responses toward the socially accepted response). To test for this bias, we examined the relationship between socioeconomic indicators and the specific/general physician trust differential, following Hays and Ware's finding that this bias is stronger among lower socioeconomic groups in their study of satisfaction measures. We found no indication of a socioeconomic relationship in our study, other than a somewhat greater differential among those with higher education, which is contrary to the predicted direction of the bias. This suggests that the social desirability bias in our trust survey is not especially strong, although it is possible the bias may exist at some level but is masked by other tendencies, such as an overall lower level of general trust by people in minority groups. Indeed, our failure to find lower trust among minority groups may itself be the result of an undetected and counteracting social desirability bias.
In addition to a positive bias that might arise from general social norms, we also considered a form of biased response that might arise from a personal desire to be liked by one's physician, or the fear that conveying displeasure to one's physician will harm the relationship. Since this tendency would not apply to general trust, it might magnify the observed difference between physician and general trust. To guard against this, interviewers stressed that we have no connection with subjects' physicians, and subjects were not required to identify their physicians.
Finally, higher trust ratings for individual physicians could simply be a type of selection bias that arises from the fact that, as people encounter a range of different providers, they naturally choose to remain with those in whom they have the most trust. Therefore, any side-by-side assessment of physicians in general and one's current physician is likely to produce higher ratings for the latter.
This initial assessment of trust in physicians in general has a number of limitations that merit further investigation. Our findings are based on a cross-sectional telephone survey of 502 adults that included only a small sampling of populations with specialized characteristics and that relied on self-reported attitudes and behaviors. To learn more about this form of trust, future studies should have a longitudinal or controlled intervention design, they should use more objectively assessed or independently observed measures of the correlates of trust, and they should include a larger and more diverse sample. Trust in physicians and medical institutions deserve this deeper and more rigorous study, for it is a vital aspect of health care relationships that may mediate many important behaviors and outcomes.