Data were split into training, internal test set and external test set as displayed
| Feature domain | Training set | Internal test | External test |
| Sample size | N=3234 | N=809 | N=2248 |
| Demographic | |||
| Sex=male (%) | 1345 (41.6) | 344 (42.5) | 947 (42.1) |
| Age (%) | |||
| ≤60 years | 1512 (46.8) | 391 (48.3) | 929 (41.3) |
| 60–70 years | 1001 (31.0) | 239 (29.5) | 872 (38.8) |
| ≥70 years | 721 (22.3) | 179 (22.1) | 447 (19.9) |
| Body mass index (%) | |||
| <18.5 | 7 (0.2) | 3 (0.4) | 6 (0.3) |
| 18.5 to <25 | 787 (24.3) | 204 (25.2) | 357 (15.9) |
| 25–30 | 1281 (39.6) | 316 (39.1) | 849 (37.8) |
| ≥30 | 1159 (35.8) | 286 (35.4) | 1036 (46.1) |
| Ethnicity (%) | |||
| White/Caucasian | 2636 (81.5) | 655 (81.0) | 1923 (85.5) |
| Black/African | 526 (16.3) | 131 (16.2) | 299 (13.3) |
| Hispanic/Latino | 16 (0.5) | 4 (0.5) | 5 (0.2) |
| Other | 56 (1.7) | 19 (2.3) | 21 (0.9) |
| Educational attainment (%) | |||
| Less than high school graduate | 87 (2.7) | 27 (3.3) | 67 (3.0) |
| High school graduate | 386 (11.9) | 108 (13.3) | 505 (22.5) |
| College/associate degree/technical school after high school | 762 (23.6) | 192 (23.7) | 601 (26.7) |
| College graduate | 712 (22.0) | 166 (20.5) | 459 (20.4) |
| Some graduate school | 272 (8.4) | 63 (7.8) | 199 (8.9) |
| Graduate degree | 1015 (31.4) | 253 (31.3) | 417 (18.5) |
| Medical history | |||
| Arthritis medical history (%) | |||
| No arthritis history | 1906 (58.9) | 480 (59.3) | 1103 (49.1) |
| At least one OA/degenerative disease | 1027 (31.8) | 262 (32.4) | 758 (33.7) |
| Gout/other | 140 (4.3) | 32 (4.0) | 124 (5.5) |
| OA/degenerative disease and gout/other | 105 (3.2) | 21 (2.6) | 126 (5.6) |
| Unknown | 56 (1.7) | 14 (1.7) | 137 (6.1) |
| Short-Form 12 Mental (mean (SD)) | 53.72 (7.92) | 53.48 (7.98) | 53.91 (8.94) |
| Short-Form 12 Physical (mean (SD)) | 49.54 (8.65) | 49.63 (8.76) | 46.43 (10.38) |
| Imaging—OA severity | |||
| Kellgren and Lawrence Grade Left Knee (%) | |||
| 0: Normal | 1243 (38.4) | 311 (38.4) | 1098 (48.8) |
| 1: Minimal | 592 (18.3) | 133 (16.4) | 379 (16.9) |
| 2: Radiographic tibiofemoral knee OA | 860 (26.6) | 234 (28.9) | 321 (14.3) |
| 3: Moderate OA | 433 (13.4) | 102 (12.6) | 320 (14.2) |
| 4: Severe OA | 106 (3.3) | 29 (3.6) | 130 (5.8) |
| Kellgren and Lawrence grade right knee (%) | |||
| 0 | 1289 (39.9) | 342 (42.3) | 1022 (45.5) |
| 1 | 607 (18.8) | 118 (14.6) | 390 (17.3) |
| 2 | 793 (24.5) | 216 (26.7) | 372 (16.5) |
| 3 | 448 (13.9) | 105 (13.0) | 347 (15.4) |
| 4 | 97 (3.0) | 28 (3.5) | 117 (5.2) |
| History of intervention | |||
| No analgesics (%) | 2478 (76.6) | 624 (77.1) | 448 (19.9) |
| No arthritis medication (%) | 3195 (98.8) | 799 (98.8) | 1549 (68.9) |
| No osteoporosis medication (%) | 2813 (87.0) | 705 (87.1) | 1829 (81.4) |
| No previous arthroscopy (%) | 2690 (83.2) | 656 (81.1) | 1913 (85.1) |
| No previous meniscectomy (%) | 2763 (85.4) | 678 (83.8) | 1920 (85.4) |
| No previous ligament repair surgery (%) | 3127 (96.7) | 781 (96.5) | 2152 (95.7) |
| No previous other surgery(%) | 3143 (97.2) | 786 (97.2) | 2192 (97.5) |
| Outcome | |||
| TKR at 5 year (%) | 158 (4.9) | 33 (4.1) | 106 (4.7) |
| TKR at 2 year (%) | 43 (1.3) | 7 (0.9) | 28 (1.2) |
To prevent data leakage, all entries from any given patient were only allowed to be in one of the three sets.
OA, osteoarthritis; TKR, total knee replacement.