Two of the earliest studies of patient adherence and physician-patient communication involved ratings of audiotaped visits; physician communication was positively related to adherence to several different regimens.26,27
Since that time, the study of medical communication and its outcomes has flourished. Communication is an essential component of the medical care process,8,28
and through the therapeutic physician-patient relationship, patients are informed about their regimens, encouraged and supported in their motivation, and offered assistance in gathering and using needed resources to adhere.29
Patient nonadherence continues to be a challenge for medical professionals, patients, and researchers, however, with review evidence indicating that 25% to 50% of patients are nonadherent.9,16
A lack of consensus remains about the most important barriers to and strategies for achieving adherence; the present meta-analytic study makes a compelling argument for the importance of improving physician-patient communication.
Summarizing a total of 127 studies, this meta-analysis supports the prediction that patient adherence is significantly related to the communication of physicians, and that adherence can be improved when physicians are trained to be better communicators. Physician skill at communicating in the medical visit may be a central factor in achieving patient adherence because it improves the transmission and retrieval of important clinical and psychosocial information,30,31
facilitates patient involvement in decision making,32–34
allows open discussion of benefits, risks, and barriers to adherence,13, 35,36
builds rapport and trust37
and offers patients verbal and nonverbal support and encouragement.38
This meta-analysis summarizes the entire literature with robust, random effects model tests across a broad range of samples, varying measures, and a broad range of treatment regimens. Patients of physicians who communicate well have 19% higher adherence, and training physicians in communication skills improves patient adherence by 12%. While these effect sizes may initially appear to be modest, when compared with many standard medical interventions [eg, Tamoxifen as prevention for breast cancer (.04), Plavix and reduced risk of serious cardiac events (.04), and low dose Warfarin and prevention of blood clots (.15)], they are actually quite impressive.19,39
Substantive moderators of the effects are of particular interest here; they include pediatric (versus adult) care, and physician status as a resident. These findings suggest first that effective communication might be even more important in achieving adherence in pediatric care than in adult care, perhaps because pediatricians must communicate at the level of both child and parent, and must present information about recommended regimens to ensure that both children and parents understand. The greater effect of communication on patient adherence among residents may suggest that with lower levels of experience in patient and disease management, residents may need the extra interpersonal skills of effective communication to achieve better adherence and better patient health care outcomes.
A number of methodological, design, and measurement moderators were significant, supporting past research on the importance of these factors in studies of adherence.9
These included physician communication assessment by others (not the patient), objective measurement of patient adherence, smaller patient sample size, and fewer physicians in the study. Objective communication assessment (independent of patients) appears to be a stronger predictor of adherence than patient-assessed communication; this argues for the importance of observational studies with assessment of communication by neutral observers. It is possible that objective measures may have less measurement error and greater validity than self-report measures, although this issue continues to be debated. It may also be helpful for researchers to consider designing studies with larger numbers of patients and physicians, to increase the power available, particularly in intervention research. Overall, these measurement and design moderators suggest that the outcomes of studies on adherence are affected by the methodological choices made; such variation should continue to be examined.
There was also a significant effect of physician communication skill training on the outcome of patient adherence. Several moderators increased the effect of communication training on patient adherence. When patients’ illness was less severe, physician communication training had a greater effect on increasing their adherence. This finding is of interest considering past research showing that patients who are more severely ill with more serious diseases are less adherent.19
The message is clear that training physicians to be better communicators improves their patients’ adherence, although more studies are needed to make stronger causal claims. Studies suggest that communication skills training is effective at changing communicative behavior40,41
but this is the first analysis to compile all published evidence that the achievement of adherence is one benchmark of success of communication skills training programs for physicians.
Strengths, Limitations, and Research Recommendations
Although several search strategies were employed in this meta-analysis, it is possible that some studies were missed. While studies with statistically significant findings may have been more likely to be published, large fail-safe n
s make it unlikely that the present results were affected. Only studies of physicians’ communication were included here; communication of nurses and other health care professionals, and the effect on patient adherence of interventions to improve patients’
communication skills should be the subject of future meta-analytic work. 42–44
Finally, because no studies have compared various approaches to reliable and valid measurement of adherence and communication, and various experimental designs, it was not possible here to pinpoint how the findings might be influenced by methodological choices.
Future research should focus on training both physicians and patients in the same intervention, assessing which aspects of communication are most crucial for patient outcomes, incorporate multiple time points of follow-up, elucidate whether certain groups of physicians may benefit more from communication skills training, and attend to issues of adherence and communication unique to both primary and specialty care.
The results of this meta-analysis indicate that the odds of patient adherence are 2.16 times higher if a physician communicates effectively. This odds ratio is comparable to that of other important predictors in meta-analytic work (practical social support (3.6) and emotional support (1.83)17
, depression (3.03)18
, and perceptions of disease severity (2.5).19
The present meta-analysis goes beyond correlational connections to adherence, by demonstrating the overall significant effect of training communication
to influence adherence. There are also broader economic and health care policy implications of this finding. The National Ambulatory Medical Care Survey reported that 963.6 million medical visits were made over the course of 2005.45
Employing the percentage difference in adherence for patients whose physician communicated well versus patients whose physician did not (19%), we calculate that over 183 million visits that resulted in patient nonadherence would have resulted in better patient adherence if the physician had strong interpersonal communication. These estimates are only suggestive, of course, but point to the potential importance of communication in reducing wasted health care resources that result from nonadherence. It is, of course, essential to note that adherence contributes to better outcomes only
when diagnosis and treatment are correct and appropriate, underscoring the centrality of promoting adherence to evidence-based care that is targeted to the benefit of the individual patient.46
Training in communication is an essential, and effective, component of medical education and may be even more important in residency training for physicians.47
Interventions should be broad-based, focusing on verbal and nonverbal communication, 48
affective/psychosocial and instrumental/task-oriented behavior,49
and creation of opportunities for active patient involvement.43
Interventions should evaluate effects on multiple patient outcomes in addition to improvement in communication skills.42
These findings also have implications for designing interventions to enhance adherence which should address multiple risk factors of nonadherence. 49
Interventions might best be developed to be personalized, identifying the factor(s) most relevant for a particular patient and tailoring the intervention accordingly.50
For many patients, being able to communicate openly and honestly with their physician about their own challenges with a regimen, obtaining all of the information they need, feeling supported and encouraged, and feeling involved in making decisions about their care may be of great benefit to their achievement of adherence. Such effective communication may help to reduce barriers that stand in the way of optimal health outcomes.