Table 2.
Characteristics of Cohort II by race
| Characteristic | Patients in Cohort II (%) | |||
|---|---|---|---|---|
| Total (n = 91,599) | African American (n = 4894) | Caucasian (n = 86,705) | p Value* | |
| Hospital admission† | ||||
| High-quality hospital | 9.2 | 8.0 | 9.2 | < 0.001 |
| Low-quality hospital | 12.8 | 14.7 | 12.7 | |
| Intermediate-quality hospital | 78.0 | 77.3 | 78.1 | |
| Age | ||||
| 65–69 years | 19.7 | 26.9 | 19.3 | < 0.001 |
| 70–74 years | 36.1 | 37.2 | 36.0 | |
| 75–79 years | 25.7 | 22.1 | 25.9 | |
| 80–84 years | 14.3 | 10.8 | 14.5 | |
| 85–89 years | 3.9 | 2.6 | 4.0 | |
| ≥ 90 years | 0.4 | 0.5 | 0.4 | |
| Gender | ||||
| Male | 35.3 | 20.3 | 36.2 | < 0.001 |
| Female | 64.7 | 79.7 | 63.8 | |
| Residence location | ||||
| Rural | 8.0 | 3.7 | 8.3 | < 0.001 |
| Urban | 92.0 | 96.3 | 91.7 | |
| Median distance (miles) | 8.9 | 6.1 | 9.1 | < 0.001 |
| Zip code-level education (median of percent population with ≥ 12 years education) | 83.0 | 74.0 | 84.0 | < 0.001 |
| Median zip code-level income (US dollars) | 40,037 | 32,980 | 40,316 | < 0.001 |
| Comorbidity | ||||
| Congestive heart failure | 4.9 | 6.2 | 4.8 | < 0.001 |
| Neurologic disease | 2.0 | 1.9 | 2.0 | 0.408 |
| Chronic renal failure | 1.9 | 3.1 | 1.9 | < 0.001 |
| Chronic obstructive pulmonary disease | 13.4 | 15.6 | 13.3 | < 0.001 |
| Arrhythmia | 14.0 | 9.9 | 14.2 | < 0.001 |
| Liver disease | 0.4 | 0.5 | 0.4 | 0.441 |
| Weight loss | 0.2 | 0.3 | 0.2 | 0.113 |
| Valvular disorder | 5.2 | 3.5 | 5.3 | < 0.001 |
| Hypothyroidism | 15.9 | 9.3 | 16.2 | < 0.001 |
| Coagulopathy | 1.5 | 1.4 | 1.5 | 0.721 |
| Lymphoma | 0.3 | 0.1 | 0.3 | 0.070 |
| Pulmonary circulatory disease | 1.1 | 1.3 | 1.0 | 0.127 |
| Peripheral vascular disease | 2.2 | 2.6 | 2.2 | 0.048 |
| Fluid disorder | 8.1 | 9.4 | 8.0 | < 0.001 |
| Paralysis | 0.1 | 0.1 | 0.1 | 0.797 |
| Psychosis | 0.5 | 0.5 | 0.5 | 0.746 |
| Metastatic cancer | 0.1 | 0.1 | 0.1 | 0.161 |
| High-risk condition | 0.1 | 0.1 | 0.1 | |
| Cancer with bone involvement | 0.1 | 0.1 | 0.1 | 0.333 |
| Femur fracture | 0.6 | 0.6 | 0.6 | 0.970 |
| Previous joint arthroplasty | 0.5 | 0.5 | 0.5 | 0.955 |
| Degenerative disease as indication for TKA | 0.1 | 0.1 | 0.1 | 0.127 |
| Knee infection as indication for TKA | 2.3 | 1.8 | 2.3 | 0.018 |
* For comparisons between Caucasian and African American patients based on chi-square tests for categorical variables and nonparametric Wilcoxon tests for continuous variables; †high-quality hospitals were below the 20th percentile of the ranking of risk-adjusted complication rate; low-quality hospitals were above the 80th percentile of the ranking of risk-adjusted complication rate; intermediate-quality hospitals were in the middle.