In this sample of primary care patients with chronic knee/hip pain who were potential candidates for joint replacement, we found significant racial differences in expectations for joint replacement surgery outcomes using a comprehensive, well-validated survey instrument. These differences were not explained by racial variation in the age or sex distribution of the patient populations, nor were they explained by differences in geographic location, socioeconomic status, educational level, health literacy, trust in physicians, or social support between African American and white patients.
The clinical or policy significance of a modest, 4–6-point difference in JRES scores, equivalent to a standardized difference (i.e., fraction of a standard deviation) of 0.3–0.4, is uncertain. Because our study was a cross-sectional design, it was not possible to ascertain if patients with lower JRES scores were actually less likely to undergo surgery in subsequent months and years. However, a growing body of evidence suggests a strong correlation between patients’ expectations of joint replacement surgery and their stated willingness to undergo surgery (9
). Future longitudinal studies are necessary to clearly quantify the relationship between patients’ expectations and joint replacement surgery rates.
Our findings add to substantial research that has explored the root causes for racial differences in the utilization of joint replacement surgery for knee and hip OA. Ibrahim et al previously reported that, compared with white patients, African American patients with knee or hip OA are less likely to perceive joint replacement as an effective treatment option (8
). Another study by Ibrahim et al assessing patient familiarity with joint replacement and expectations of surgical outcomes found that African American patients were less familiar with the details of joint replacement surgery and the duration of the expected recovery period (23
). The current study expands on these previous findings by using a more comprehensive (i.e., 17- or 18-item), integrated (i.e., single composite score), well-validated measure of joint replacement surgery expectations. We also enrolled sufficient numbers of patients to verify these findings separately among patients with knee OA and those with hip OA. Additionally, in multivariable analyses, we adjusted for several factors likely to confound the relationship between race and joint replacement expectations, including other demographic factors, socioeconomic variables, literacy, social support, and trust. Indeed, African American and white patients in our sample differed markedly in age, geographic location, socioeconomic status, educational attainment, health literacy, and social support. These factors are all likely to influence patient expectations of surgery independent of race, yet when we adjusted for the independent effect of these variables, racial differences in patient expectations persisted. Additionally, we found little evidence of interaction between race and other predictors of expectations. Generally, significant predictors of higher expectations, such as employment and greater trust in physicians, were similarly influential in both racial groups.
If racial differences in joint replacement expectations are not mediated by the many factors that we explored, what are the central causes for these racial differences? Among the remaining possibilities are racial differences in the composition of patients’ social networks, through which trusted information regarding the benefit of knee and hip replacement may be obtained, as well as differences in access to other sources of information about joint replacement such as the Internet. Our own prior research suggests that information received through informal channels (rather than, for example, a physician visit) is often critical in influencing patients’ attitudes toward medical technology (25
With any elective surgery, it is vital that patient-physician decision making truly be shared, and that patient autonomy be respected (26
). As such, a decision to decline elective joint replacement surgery by a patient with moderate or severe arthritis is not necessarily irrational, and may reflect an accurate self-assessment of individual circumstances and/or risk preferences (27
). However, a decision to decline beneficial therapy based on erroneous, incomplete, or outdated information is not an issue of autonomy or preference, but of disparity in knowledge (9
). More African American patients may lack access to accurate information (e.g., interpersonal networks where receipt of joint replacement is common, etc.) about the experiences after surgery than do white patients. In a context in which trust in the health system is low, African American patients may therefore discount the benefits of surgery as described by health care providers (28
Interventions designed to improve the accuracy of, and reduce racial differences in, patients’ understanding of the outcomes of joint replacement surgery may be a particularly effective way of reducing racial disparities in utilization of this effective treatment option. To be effective, such interventions should not only increase the quality and quantity of information available to patients, but also increase the number and variety of sources of trusted information. Weng et al have pilot tested an educational intervention (a video and tailored decision aid) designed to reduce disparities in expectations of knee replacement, measured by the anticipated WOMAC score after surgery (29
). This intervention lowered the expected WOMAC score for both pain and physical function among African American participants. Although these findings are preliminary, they suggest that racial differences in expectations are modifiable. Peer counselors, testimonials, compelling presentations of race- and ethnicity-specific outcome data, culturally competent media presentations, and the establishment of patient networks all may be effective in reducing racial differences in expectations and consequently improve equity in joint replacement surgery rates.
In interpreting our results, it is appropriate to acknowledge several limitations. First, this research is a cross-sectional study, which limits causal inference. In particular, we did not assess whether patients were anticipating surgery in the near future, nor did we later determine who had undergone surgery subsequent to the survey. Respondents who were facing the tangible prospect of joint replacement surgery may have responded differently than those patients for whom surgery was a more hypothetical option. Second, although our recruitment of nearly 1,000 patients over 2 years’ time improved our likelihood of attracting somewhat more reluctant participants to enter the research cohort, it is possible that our method of enrollment selected patients who were generally more trusting of the health system or of the VA in particular. Patients with frequent visits to the medical centers also had more opportunities to be enrolled, so we may have inadvertently enrolled a cohort of patients who were more connected to the health system than typical veterans. Third, this study excluded patients who previously had undergone joint replacement surgery. If one racial group had greater access to surgery than the other regardless of expectations, it is possible that the racial differences we observed were an artifact created by the pool of presurgical knee/hip OA patients in one racial group being depleted faster than the other racial group. However, we believe this phenomenon likely would have diminished the apparent racial difference in expectations, because it is probable that white patients would have had more facilitated access to surgery. As such, it would have been less likely for us to have enrolled white patients who were both highly favorable of joint replacement surgery but who had not yet undergone surgery, thus potentially reducing the mean expectations score among white participants compared with African American participants. Finally, the racial difference we observed could have been an artifact produced by the JRES instrument itself, if the instrument performed differently across racial groups. However, the highly similar distributional form of the responses, the nearly identical Cronbach’s alpha values, and the similar results of the regression analyses stratified by race suggest this is unlikely.
In this study of primary care patients with chronic knee/hip pain who were potential candidates for joint replacement, we found significant racial differences in patient expectations regarding joint replacement surgery. These findings were independently observed for both hip OA and knee OA patients. The racial differences in expectations persisted despite adjustment for multiple potential confounders. Future studies should explore interventions designed to reduce racial disparities in expectations of the benefits and risks of joint replacement. Such interventions are likely to improve the quality of patient decision making, while potentially reducing racial differences in utilization of joint replacement and subsequent quality of life for patients with OA.