Methods
Men and women 55 years of age or older with a diagnosis of knee OA who were followed at a large outpatient multispecialty clinic in Houston, Texas were surveyed. Subjects self-identified as white, African-American, or Hispanic were eligible for enrollment. Survey categories included questions about previous physician recommendations for TKR, patient preferences for TKR, familiarity with TKR, perceptions of efficacy and risk of TKR, trust in physicians and the health system, and perceptions on control of health (internal control vs. control by powerful others vs. chance). Demographic information (including religion and religiosity) was collected. Severity of knee OA was assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).
Results
66 subjects were included in each of the three racial/ethnic groups surveyed. 63% of patients were female with a mean age of 64 years. White and African-American subjects tended to have more years of education than Hispanic subjects (mean years of education 15 and 14.3 vs. 11.3, respectively) while white subjects tended to have a higher income than African American and Hispanic subjects. These differences were consistent the demographics of Houston. White and Hispanic subjects reported better overall health than African-American patients. WOMAC scores for knee pain, stiffness, and function were significantly higher in African-American subjects compared to white and Hispanic subjects, the later reporting the lowest WOMAC scores.
Previous physician recommendations for TKR No significant differences were observed across ethnic groups.
Patient preferences for TKR White subjects were more likely than African-American or Hispanic subjects to have considered TKR in the past (42% vs. 30% vs. 24%, respectively; p=0.07) and more likely to consider TKR if their arthritis became worse (97% vs. 85% vs. 76%, respectively; p=0.002).
Familiarity with TKR – White subjects were more likely than African-American or Hispanic subjects to have heard about TKR (100% vs. 91% vs. 80%, respectively; p<0.001) and have a relative or close friend who had undergone TKR (88% vs. 70% vs. 58%, respectively; p=0.001).
Perceptions of efficacy and risk of TKR The perception of efficacy of TKR was significantly higher in white subjects than in African-American or Hispanic subjects (3.9 vs. 3.6 vs. 3.5, respectively (1 < 5 scale), p=0.2); however, the perception of risk of TKR was not significantly different among the three ethnic groups (3.0-3.2 on 1 < 5 scale).
Trust in physicians and health system Trust in physicians was not significantly different among the three ethnic groups (6.7-7.3 on 1 < 10 scale). Trust in the health system was the highest among African-American subjects and lowest among white subjects (8.2 vs. 6.4, respectively (1 < 10 scale), p<0.001). African-American and Hispanic subjects reported greater strength of religious beliefs than white subjects (3.4 and 3.2 vs. 2.9, respectively (1 < 4 scale); p=0.04).
Perceptions on control of health Internal control of health was not significantly different among the three ethnic groups. Whites reported greater beliefs in the power of chance and powerful others to influence health than either African-American or Hispanic subjects. In multivariate analysis, ethnicity was significantly associated with consideration of TKR, with white subjects 3 times more likely than African-American subjects and 6 times more likely than Hispanic subjects to respond that they would consider TKR if recommended by their physician. Perceived efficacy was the only other significantly associated variable.
Conclusions
Ethnic disparities in the consideration of TKR are related to differences in familiarity with and perception of efficacy of TKR and not racial/ethnic bias in physician recommendation for TKR.
Editorial Comment
This study highlights important factors that may partially explain the known racial/ethnic disparities in TKR utilization. Importantly, patient-based factors appear to have more influence than racial/ethnic differences in physician recommendation for the procedure. These results suggest that campaigns to increase awareness of the benefits of TKR in minority communities may be helpful in increasing the frequency of this procedure in these populations, particularly as perceptions of risk were not greater in these groups. Somewhat surprisingly, trust in the health system was highest in minority populations. This trust may partially explain why underprivileged minorities are more likely to elect to have joint replacement surgery in higher-risk low-volume centers.
Geographic differences are known to account for some of the racial/ethnic disparities in TKR utilization. Thus, the findings from this single-center investigation may not necessarily reflect those of other geographic locations. In particular, physician bias in recommending TKR may be more of a factor influencing TKR utilization in other locales outside of Houston. Nevertheless, this study is important in identifying areas for potential intervention that could be applied on a national scale.
