Table 1.
Baseline characteristics of TJR cases and controls
| TKR n = 89 536 | THR n = 99 682 | |||
|---|---|---|---|---|
| Cases (%) n = 44 768 | Controls (%) n = 44 768 | Cases (%) n = 49 841 | Controls (%) n = 49 841 | |
| Females | 24 912 (55.6) | 24 912 (55.6) | 29 724 (59.6) | 29 724 (59.6) |
| Number of GP consultations in the year prior to surgery (mean (SD)) | 41.3 (25.7) | 28.9 (26.2) | 40.2 (27.0) | 28.0 (26.1) |
| Age at index date (years, (SD)) | 69.5 (9.5) | 69.5 (9.5) | 68.8 (11.5) | 68.8 (11.5) |
| Socioeconomic status | ||||
| Low | 6945 (15.5) | 7120 (15.9) | 8248 (16.5) | 8054 (16.2) |
| Low‐medium | 7176 (16.0) | 7011 (15.7) | 8200 (16.5) | 8015 (16.1) |
| Medium | 5763 (12.9) | 5626 (12.6) | 6287 (12.6) | 6113 (12.3) |
| Medium‐high | 4533 (10.1) | 4451 (9.9) | 4521 (9.1) | 4741 (9.5) |
| High | 3077 (6.9) | 3240 (7.2) | 2896 (5.8) | 3191 (6.4) |
| Missing | 17 274 (38.6) | 17 320 (38.7) | 19 689 (39.5) | 19 727 (39.6) |
| BMI, most recent prior to TJR surgery | ||||
| BMI (kg m–2, mean (SD)) | 29.7 (5.2) | 27.0 (5.1) | 27.6 (5.0) | 26.8 (5.0) |
| <25.0 kg m–2 | 7248 (16.2) | 14 415 (32.2) | 13 789 (27.7) | 16 495 (33.1) |
| 25–29.9 kg m–2 | 16 245 (36.3) | 15 243 (34.0) | 17 982 (36.1) | 16 524 (33.2) |
| 30–34.9 kg m–2 | 11 258 (25.1) | 6464 (14.4) | 8839 (17.7) | 6647 (13.3) |
| ≥35.0 kg m–2 | 6254 (14.0) | 2604 (5.8) | 3585 (7.2) | 2772 (5.6) |
| Missing | 3763 (8.4) | 6042 (13.5) | 5646 (11.3) | 7403 (14.9) |
| HbA1c most recent within the year prior to TJR surgery | ||||
| HbA1c (%, mean (SD)) | 6.9 (1.2) | 7.1 (1.4) | 6.8 (1.2) | 7.2 (1.4) |
| <6.5% | 1811 (4.0) | 1422 (3.2) | 1629 (3.3) | 1406 (2.8) |
| 6.5–7.9% | 2331 (5.2) | 1976 (4.4) | 1623 (3.3) | 1837 (3.7) |
| 8–9.4% | 542 (1.2) | 586 (1.3) | 411 (0.8) | 550 (1.1) |
| ≥9.5 | 189 (0.4) | 299 (0.7) | 133 (0.3) | 310 (0.6) |
| Missing | 39 895 (89.1) | 40 485 (90.4) | 46 045 (92.4) | 45 738 (91.8) |
| Fasting glucose most recent within the year prior to TJR surgery | ||||
| Fasting glucose (mean (SD)) | 5.7 (1.5) | 5.7 (1.7) | 5.6 (1.4) | 5.7 (1.7) |
| <6 mmol l–1 | 3791 (8.5) | 3143 (7.0) | 3351 (6.7) | 3016 (6.1) |
| 6–7.5 mmol l–1 | 818 (1.8) | 613 (1.4) | 580 (1.2) | 590 (1.2) |
| 7.5–8.9 mmol l–1 | 248 (0.6) | 152 (0.3) | 122 (0.2) | 167 (0.3) |
| ≥9.0 mmol l–1 | 156 (0.3) | 149 (0.3) | 145 (0.3) | 164 (0.3) |
| Missing | 39 755 (88.8) | 40 711 (90.9) | 45 643 (91.6) | 45 904 (92.1) |
| eGFR most recent within the year prior to TJR surgery | ||||
| eGFR ml min–1 1.73m–2 (mean (SD)) | 71.9 (17.9) | 70.8 (17.9) | 71.9 (18.9) | 70.4 (18.1) |
| eGFR ≥90 | 4720 (10.5) | 3464 (7.7) | 4998 (10.0) | 3654 (7.3) |
| 60 ≤ eGFR < 90 | 19 900 (44.5) | 16 953 (37.9) | 19 389 (38.9) | 17 082 (34.3) |
| 30 ≤ eGFR <60 | 8366 (18.7) | 7398 (16.5) | 8504 (17.1) | 8028 (16.1) |
| 15 ≤ eGFR <30 | 171 (0.4) | 272 (0.6) | 280 (0.6) | 283 (0.6) |
| eGFR <15 | 23 (0.1) | 53 (0.1) | 49 (0.1) | 71 (0.1) |
| eGFR missing | 11 588 (25.9) | 16 628 (37.1) | 16 621 (33.3) | 20 723 (41.6) |
| History of comorbidity ever before primary TJR surgery | ||||
| Angina pectoris | 4615 (10.3) | 4309 (9.6) | 4273 (8.6) | 4603 (9.2) |
| AMI | 1929 (4.3) | 2336 (5.2) | 2139 (4.3) | 2308 (4.6) |
| Ischaemic stroke | 332 (0.7) | 468 (1.0) | 347 (0.7) | 483 (1.0) |
| Haemorrhagic stroke | 191 (0.4) | 261 (0.6) | 239 (0.5) | 275 (0.6) |
| Valve disorders | 482 (1.1) | 587 (1.3) | 611 (1.2) | 609 (1.2) |
| Peripheral vascular disorders | 550 (1.2) | 778 (1.7) | 664 (1.3) | 764 (1.5) |
| Ulcers | 3280 (7.3) | 2441 (5.5) | 3250 (6.5) | 2815 (5.6) |
| Non‐hip/femur fractures in the previous year | 559 (1.2) | 623 (1.4) | 957 (1.9) | 696 (1.4) |
| History of comorbidity 5 years before primary TJR surgery | ||||
| Retinopathy | 884 (2.0) | 911 (2.0) | 643 (1.3) | 850 (1.7) |
| Neuropathy | 551 (1.2) | 441 (1.0) | 499 (1.0) | 428 (0.9) |
| History of drug use within 6 months before primary TJR surgery | ||||
| NSAIDs | 19 522 (43.6) | 5773 (12.9) | 22 467 (45.1) | 6259 (12.6) |
| All NIAD | 3430 (7.7) | 3075 (6.9) | 2511 (5.0) | 3037 (6.1) |
| Biguanides | 2780 (6.2) | 2406 (5.4) | 1995 (4.0) | 2388 (4.8) |
| Sulphonylureas | 1497 (3.3) | 1573 (3.5) | 1206 (2.4) | 1568 (3.1) |
| Thiazolidinediones | 540 (1.2) | 428 (1.0) | 311 (0.6) | 420 (0.8) |
| Glinides | 38 (0.1) | 28 (0.1) | 18 (0.0) | 26 (0.1) |
| GLP‐1agonists | 53 (0.1) | 28 (0.1) | 27 (0.1) | 17 (0.0) |
| DPP‐4 inhibitors | 93 (0.2) | 89 (0.2) | 62 (0.1) | 60 (0.1) |
| Insulins | 747 (1.7) | 825 (1.8) | 580 (1.2) | 837 (1.7) |
TJR total joint replacement, TKR total knee replacement, THR total hip replacement, GP General Practitioner, BMI body mass index, HbA1c glycated haemoglobin, eGFR estimated glomerular filtration rate, AMI acute myocardial infarction, NSAID non‐steroidal anti‐inflammatory drugs, NIAD non‐insulin antidiabetic drug, GLP‐1 glucagon‐like peptide‐1, DPP‐4 dipeptidyl peptidase‐4.