TABLE IV.
Risk of All-Cause or TKA-Specific Readmission 30 Days After TKA Based on Patient Characteristics (N = 377,705)
| 30-Day Readmissions* |
||||||
| CMS TKA-Specific† (N = 2,449; C-Statistic = 0.66) |
Expanded TKA-Specific‡ (N = 6,784; C-Statistic = 0.66) |
All-Cause§ (N = 22,076; C-Statistic = 0.69) |
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| OR (95% CI) | P Value | OR (95% CI) | P Value | OR (95% CI) | P Value | |
| Age group (vs. <65 yr) | ||||||
| 65-75 yr | 0.78 (0.69, 0.89) | <0.001 | 0.84 (0.78, 0.91) | <0.001 | 0.98 (0.94, 1.03) | 0.460 |
| 76-85 yr | 0.94 (0.82, 1.08) | 0.394 | 1.01 (0.93, 1.10) | 0.792 | 1.25 (1.19, 1.31) | <0.001 |
| >85 yr | 1.28 (1.02, 1.61) | 0.032 | 1.32 (1.15, 1.52) | <0.001 | 1.67 (1.54, 1.80) | <0.001 |
| Sex | ||||||
| Male vs. female | 1.34 (1.23, 1.46) | <0.001 | 1.41 (1.34, 1.49) | <0.001 | 1.26 (1.22, 1.30) | <0.001 |
| Race/ethnicity (vs. white) | ||||||
| Black | 1.20 (1.05, 1.37) | 0.009 | 1.24 (1.14, 1.34) | <0.001 | 0.99 (0.94, 1.04) | 0.583 |
| Hispanic | 1.00 (0.84, 1.20) | 0.979 | 1.18 (1.07, 1.30) | 0.001 | 0.93 (0.87, 0.99) | 0.029 |
| Asian | 0.65 (0.42, 1.02) | 0.060 | 0.86 (0.68, 1.09) | 0.216 | 0.65 (0.56, 0.75) | <0.001 |
| Other | 1.03 (0.85, 1.23) | 0.790 | 1.02 (0.91, 1.14) | 0.695 | 0.82 (0.76, 0.88) | <0.001 |
| Missing | 1.15 (0.92, 1.44) | 0.230 | 1.08 (0.93, 1.24) | 0.308 | 1.62 (1.52, 1.72) | <0.001 |
| Insurance status (vs. private) | ||||||
| Medicare | 1.31 (1.16, 1.49) | <0.001 | 1.26 (1.17, 1.36) | <0.001 | 1.10 (1.05, 1.15) | <0.001 |
| Medicaid | 1.40 (1.16, 1.69) | <0.001 | 1.40 (1.26, 1.57) | <0.001 | 0.94 (0.87, 1.02) | 0.119 |
| Workers’ Compensation | 1.07 (0.86, 1.33) | 0.551 | 1.10 (0.97, 1.25) | 0.142 | 0.90 (0.83, 0.98) | 0.015 |
| Other | 1.20 (0.90, 1.58) | 0.214 | 1.09 (0.92, 1.30) | 0.313 | 0.86 (0.77, 0.96) | 0.007 |
| Bilateral TKA | 1.22 (1.02, 1.45) | 0.028 | 0.89 (0.79, 1.01) | 0.080 | 1.63 (1.55, 1.71) | <0.001 |
| In-hospital complications | ||||||
| Medical | 2.31 (1.99, 2.68) | <0.001 | 1.85 (1.67, 2.05) | <0.001 | 1.67 (1.57, 1.78) | <0.001 |
| Surgical | 2.70 (2.28, 3.20) | <0.001 | 2.16 (1.92, 2.43) | <0.001 | 1.41 (1.30, 1.53) | <0.001 |
| Length of hospital stay# | 1.02 (1.02, 1.03) | <0.001 | 1.03 (1.02, 1.03) | <0.001 | 1.03 (1.03, 1.04) | <0.001 |
| Discharge disposition (vs. home) | ||||||
| Short-term hospital | 4.37 (3.72, 5.14) | <0.001 | 3.04 (2.71, 3.40) | <0.001 | 4.62 (4.30, 4.98) | <0.001 |
| Skilled nursing facility | 1.19 (1.08, 1.32) | <0.001 | 1.25 (1.18, 1.32) | <0.001 | 1.49 (1.44, 1.55) | <0.001 |
| Rehabilitation facility | 0.57 (0.49, 0.67) | <0.001 | 0.42 (0.38, 0.47) | <0.001 | 2.11 (2.02, 2.20) | <0.001 |
| Other facility | 0.70 (0.59, 0.82) | <0.001 | 0.56 (0.51, 0.63) | <0.001 | 3.20 (3.07, 3.34) | <0.001 |
*
Readmission categories are not mutually exclusive.
†
Readmissions due to any of 8 diagnoses designated by the CMS as TKA-specific complications (see Appendix).
‡
Readmissions due to a diagnosis on an expanded list of TKA-specific complications, including 22 additional TKA-specific complications selected by a group of experts (see Appendix).
§
Readmissions due to all causes, including 918 conditions not included in the CMS-defined or expanded list of TKA-specific complications (see Appendix).
#
The change in risk of readmission was calculated for each additional day (unit change) that the patient stayed in the hospital.