We found that older adults trust physicians and pharmacists far more than other sources to provide them information about the comparative effectiveness and prices of prescription medicines. However, it is notable that older adults place a much higher level of trust in the abilities of their physicians to deliver information on how well a drug works for them (80%) than the price of that drug (56%). Moreover, less than half of older adults believe there are ways for physicians to do something about the cost of prescription drugs.
That just over a majority of older adults trust physicians to provide price information is especially important given that we found that trust in physicians to deliver such information is associated with lower rates of cost-related non-adherence among those with high drug spending. Due to the cross-sectional nature of our study we cannot determine whether there is a causal relationship between trust in physicians to provide this information and cost-related non-adherence. However, confidence in physicians as a source of information on prescription drugs may create opportunities for and improve the quality of doctor-patient communication about medication adherence. Thom et al (1999) reported that patients with high levels of trust in their physicians, measured by the 11-item Trust in Physician Scale, had better self-reported medication adherence than those with low levels of trust although their adherence measure was not specific to costs.21
Our findings are also consistent with those of Piette and colleagues who found that individuals with diabetes and high out-of-pocket drug costs in the Veterans Affairs health care system had a significantly higher risk of cost-related non-adherence, compared to their counterparts with low drug spending, when trust levels were low (adjusted OR, 14.0) than when trust levels were high (adjusted OR, 4.8; test of equivalence, p<0.001).22
Patient adherence behavior is affected by a number of factors other than trust in physicians and doctor-patient communication, including prescription drug advertising,30
and patients’ experiences with medication taking, among other factors.31
Trust in physicians as a broad concept has received limited attention from researchers in recent years.29,32, 33,34,21,35, 36,24
It has proven difficult to empirically measure discrete dimensions of trust, such as confidentiality, agency, competence, or information exchange. That is, items that tap these various dimensions tend to form a single scale in factor analyses.21,37,35, 36
Our goal was not to measure trust in any global sense, but rather to determine which information sources patients have confidence in to provide information about the efficacy and cost of prescription medications.
Physicians have a number of tools at their disposal to lower their patients’ pharmacy costs without compromising the quality of clinical care. Among other things, they can increase their prescribing of generics,13, 38
prescribe lower cost therapeutic substitutes12
, or reduce the total number of drugs their patients are taking.38–40
However, several barriers prevent physicians from adopting these and other strategies. Studies indicate that less than one-third of the elderly and less than one-fifth of adults have discussed medication affordability with their doctors.41–44
Physicians have identified a number of key barriers to discussing drug costs with their patients including insufficient time (44.3%), concern over patient discomfort (35.0%) and lack of habit (33.9%).38
In addition, even if doctor-patient discussions about medication costs occur, these discussions are but one factor affecting doctors’ prescribing decisions. Physicians prescribing decisions are seldom guided by their patients’ out-of-pocket costs for a particular drug or drug class due to substantial heterogeneity in formularies and cost-sharing across insurance products and the lack of information available to physicians at the point of prescribing. Widespread use of health information technology, specifically e-prescribing and decision-support systems could help improve physicians’ access to this information. In fact, e-prescribing programs equipped with formulary decision support functions have been shown to increase use of lower cost agents.45
Unfortunately, studies indicate that only 15% of medical group practices had electronic health records in 2005 and only a subset of those practices had e-prescribing capability complete with drug formulary data.46
The low levels of trust in sources other than physicians and pharmacists to provide comparative price information have important implications for efforts by third party payers to educate consumers on value-based purchasing of prescription drugs and other health care services. The success of these efforts may depend on the involvement of health professionals. Furthermore, third party payers will need to address age-related differences in trust in information sources. For example, we found that adults aged 65 and over were more likely than those 50 to 64 years old to report a high level of trust in their physicians and insurance companies to deliver drug price information.
Our paper has limitations that could affect its generalizability. Our respondents had slightly higher educational attainment and incomes than individuals 50 and older, nationally, and thus may not be representative of that population. However, the rates of cost-related non-adherence we report are virtually the same as those reported in other studies using identical question wording but different sampling methodologies.14, 27
Also, we assumed that individuals 50–64 years old with health insurance had coverage for prescription drugs. While 98% of insured individuals have prescription drug benefits47
we may have mis-classified a small subset of individuals as having drug coverage. Among individuals 65 and older, 26.6% reported not having prescription drug coverage which is higher than the 9–10% estimate from Medicare Part D enrollment data.48
This may be due to elderly respondents’ inability to identify a source of drug coverage from the list we provided rather than from a true lack of drug coverage. Finally, one could argue that some telephone interview respondents may have been more likely to report trust in various sources -- if they believed that was the goal of the study – in order to present themselves in a more favorable light to the interviewer. Thus, our overall levels of trust may be over-reported. However, there is no reason to believe that such bias affects the relative trust levels in physicians versus pharmacists and other sources of information on drug pricing and effectiveness. Therefore, our major findings should be unaffected.