Purpose: As part of a larger study looking at racial differences in utility for knee osteoarthritis (OA) and total knee arthroplasty (TKA), we use conjoint methodology to elicit preferences for surgery and determine which attributes are most important in decisions about whether to undergo TKA surgery.

Methods: We sampled equal numbers of whites (W), Hispanics (H) and African Americans (AA) from two populations: adults living in Houston, Texas (N=193) and patients treated for knee OA (N=198) in Houston. Face-to-face interviews were used to collect the demographic and conjoint scenario data. Demographic information included self-reported race/ethnicity (White, African American, Hispanic), age, gender, and income.

Hypothetical scenarios of surgical and non-surgical states for knee OA were developed. We matched each of 18 surgical scenarios with two non-surgical scenarios (one with severe and one with moderate OA), for a total of 36 paired choices. Each participant was asked to choose between the after surgery and the no surgery state for 6 of the paired scenarios.

Results: African Americans chose surgery 36% of the time (26% and 47% for the moderate and severe pre-surgery conditions respectively), Hispanics 51% of the time (37% and 64%), and Whites 45% of the time (28% and 63%).

Logistic regressions with all participants showed that African Americans but not Hispanics, were significantly less likely to chose surgery than Whites (OR 0.61 [0.41,0.92], 1.13 [0.77, 1.65] respectively. Gender and age were also significant, with women and older individuals less likely to choose surgery (0.70 [0.51, 0.95], 0.98 [0.97, 0.99]). There was no difference between the public and patient, and no effect of income level.

Levels of pain, difficulty with stairs, cost, risk of death and complications in the scenarios significantly affected the decision. When the racial/ethnic groups were analyzed separately, pain is less important for Hispanics and African Americans than for Whites. The risk of death is significant for Whites, as is the risk of complications for Whites and Hispanics, but not for African Americans.

Conclusions: African Americans are significantly less likely than Whites or Hispanics to choose a surgical scenario for the condition of knee OA. Thus, at least part of the disparity in TKA rates among racial/ethnic groups may be due to differences in preferences.