It is well recognized that health care providers, as well as patients, differ broadly in regard to their health care-related attitudes, beliefs, and expectations1–6
. For example, surveys have found that some patients prefer to take a highly active role during the clinical encounter, whereas others prefer to remain passive2,3,6
. Similar differences have been observed with regard to physicians, with some holding more autocratic, physician-centered attitudes about clinical interactions, and others holding more egalitarian, patient-centered views1,4–6
. However, the degree to which these attitudinal differences may be related to health care outcomes such as medical regimen adherence or to the effectiveness of clinical management is less clear.
Emerging evidence suggests that any attempt to consider the significance of patient or provider attitudes in isolation is insufficient (e.g.,1,4–7
). Rather, this perspective suggests that a dyadic consideration of provider and patient attitudes or beliefs is essential to understanding their potential significance in influencing outcomes. Krupat was among the first to argue that the degree of symmetry between physician and patient attitudes may be an important consideration1,5,6
. These investigators reported that patients who held similar attitudes to their physician (e.g., regarding preference for health-related information sharing) were more satisfied, more trusting, and more likely to recommend the physician to others.
More recently, we have examined whether the degree of patient-provider symmetry in the attitudes held toward health and health care delivery is associated with differences in patient adherence4
. In one study, we expanded previous assessments of attitudinal differences to include measures of health locus of control (HLOC)8
beliefs. The HLOC construct has been one of the most actively studied attitudinal predictors of patients’ health-related behavior for decades9
. Health locus of control is conceptualized as the degree to which a patient attributes the cause of health-related outcomes to internal factors under one’s own control (i.e., a patient’s own actions) or to external factors (e.g., chance, actions of the provider). Early work with this construct demonstrated that strong “internal” HLOC is associated with more positive adaptation to chronic disease when patient control over the illness or treatment is realistic, but may be maladaptive when there are impediments to exercising personal control10
. In our previous study of physician-patient dyads4
, we found that, among 146 patients seen by 16 different physicians, patients who were more similar in attitude to their providers, as indicated by HLOC scores, were more satisfied with care and self-reported better regimen adherence than patients whose control-related attitudes were less similar to those of their physicians.
Past studies involving the degree of symmetry between patient and provider attitudes have been limited in at least two important ways. First, earlier work has relied on self-ratings of patient adherence. It is well known that patients are often inaccurate in their ability to accurately self-report treatment adherence11
. In the present study, we focused on objectively assessed medication refill adherence using the VA Medical Center’s electronic pharmacy record. Second, in our earlier study, we used a general, mixed convenience sample of primary care patients, and had no available information about diagnoses or treatment. Thus, the adherence assessment was not anchored to a specific regimen or condition, and the patient sample was highly heterogeneous. In the present study, we focused on patients with confirmed diagnoses of co-morbid diabetes mellitus (DM) and hypertension (HTN) treated in VA-affiliated outpatient primary care clinics.
The majority of patients with DM who are treated in VA facilities also have HTN, and increased emphasis has been placed on the need to control HTN in patients with DM12,13
. Patients with DM are believed to get twice the benefit in cardiovascular risk reduction from HTN control compared to non-diabetics14
, and patients with DM require more rigorous HTN control than patients without DM15,16
. The population of patients with co-morbid DM and HTN is clearly a prevalent and clinically important group that has frequent contact with health care providers, whose conditions entail substantial self-management demands, and who are at high risk of increased morbidity and mortality.
In sum, the central aim of the study was to examine the extent to which patient and provider symmetry in HLOC beliefs was associated with the primary outcomes of medication refill adherence in patients with co-morbid DM and HTN. Blood pressure and glycemic control were secondary outcomes. Symmetry on the attitudinal HLOC measure was modeled before and after adjusting for patient and provider age, physician sex, patient income level, number of clinic visits between patient and provider during the 24-month index period, and physician years of practice17–19