• Race and socioeconomic status as predictors of utilization and need for total knee arthroplasty for knee osteoarthritis: Data from the OsteoArthritis Initiative study

      O'Connor, Shannon Leigh; Hochberg, Marc C.; 0000-0003-0817-258X (2016)
      Objective: Previous studies consistently report reduced rates of utilization of total knee arthroplasty (TKA) among black U.S. adults as compared with whites. This study assessed whether differences in TKA utilization rates between blacks and whites persist after including estimates of socioeconomic status and theoretical candidacy for joint replacement surgery. This study also examined whether blacks and whites differ in rate of reaching candidacy for TKA, and whether socioeconomic factors are related to reaching VTKA. Methods: This study employed data from the OsteoArthritis Initiative study. Study participants were black and white adults enrolled in the OAI study between the ages of 49 and 79 at baseline. Study aims were achieved using a discrete survival approach. Cox-analogue proportional hazards models were employed using a log minus log link to produce hazard ratios specific to respective intervals between time points. Models were fit using General Estimating Equations. Results: Results showed that blacks were significantly less likely to undergo total knee arthroplasty than whites, even after including estimates of baseline differences in BMI and number of comorbidities, baseline need for TKA, and socioeconomic status (education and income) (e^(β)=0.50, p=0.0016). Individuals who met need for TKA criteria at baseline were significantly more likely to undergoing TKA than those who did not (e^(β)=8.25, p<0.0001). Results also revealed race not to be a significant predictor of reaching need for TKA after including estimates of baseline differences in BMI and number of comorbidities. These findings persisted even with the inclusion of socioeconomic variables. Conclusions: Findings confirmed that substantial racial differences in utilization of TKA exist. The inclusion of socioeconomic status measures accounted for only a small proportion of the difference between blacks and whites in terms of TKA utilization (e^(β)=0.41 versus e^(β)=0.50). Racial differences in progression of knee OA to virtual TKA were also found, although race became non-significant after accounting for baseline differences in BMI categories (overweight and obese). Results suggest that other factors not captured in this study differentially influence the rate of TKA utilization among black and white U.S. adults.
    • Racial/ethnic differences in experimental pain sensitivity and associated factors - Cardiovascular responsiveness and psychological status

      Kim, Hee Jun; Dorsey, Susan Grace (2016)
      Background Racial/ethnic disparities related to pain in the US have been reported that racial/ethnic minorities have greater levels of chronic pain and receive lower quality of care. Underlying mechanisms to explain the racial/ethnic differences in pain is unclear. Enhanced experimental pain sensitivity is suggested to be associated with ethnic differences in clinical pain. Purpose To examine racial/ethnic differences in experimental pain sensitivity, and evaluate contribution of cardiovascular responsiveness and psychological status to racial/ethnic differences in experimental pain sensitivity. Methods The baseline data of TMD-free 3,159 individuals - non-Hispanic white (NHW): 1,637, African-American (AA): 1,012, Asian: 299, and Hispanic: 211 - from the OPPERA prospective cohort study were used. Quantitative sensory testing measures for pressure, mechanical cutaneous, and heat pain were used. Cardiovascular responsiveness measures (e.g., BP, HR, HR/MAP ratio, and heart rate variability) and psychological status (depression, anxiety, stress, coping, and catastrophizing) were included in the analyses. Structural equation modeling with maximum likelihood estimation method was used for mediation analyses. Putative mediators that showed significant racial/ethnic differences were entered into the final models simultaneously with age, gender, BMI, study site, education and income level as covariates. Results Racial/ethnic minorities showed higher pain sensitivity, including heat pain tolerance, heat pain rating (HPR), heat pain aftersensation (HPA), mechanical cutaneous pain ratings and aftersensation (MCPRAS), and mechanical cutaneous pain temporal summation (MCPTS), compared to NHWs. Catastrophizing significantly mediated the associations between ethnicity and pain sensitivity (heat pain tolerance, HPR, HPA, MCPRAS, and MCPTS) for both AAs and Asians, compared to NHWs. Coping negatively mediated the association between race/ethnicity and heat pain tolerance, HPR, and MCPTS in both AAs and Asians, compared to NHWs. HR/MAP ratio showed a significant negative mediating effect on the association between race/ethnicity (AAs vs. NHWs) and heat pain tolerance. Negative emotion mediated the associations between race/ethnicity (Asians vs. NHWs) and mechanical cutaneous pain threshold, HPR, and MCPRAS. Conclusion The identified mediators should be considered in pain management programs to implement better strategies to reduce clinical pain, especially for AAs and Asians in the US. Further clinical research is required to increase our understanding of the suggested mechanisms.