Table 1.
Results from multivariable logistic regression models showing the association between surgeon-level factors and use of new stems and cups
| Exposure | Stems | Cups | ||||||||
| Established (n=18 404)* |
New (n=2006)* |
OR† | (95% CI) | P value† | Established (n=17 167)* |
New (n=3243)* |
OR† | (95% CI) | P value† | |
| Proportion of THRs performed on patients <55 years old | ||||||||||
| <10% (ref) | 13 088 (71.1%) |
940 (46.9%) |
1 | – | – | 12 346 (71.9%) |
1682 (51.9%) |
1 | – | – |
| ≥10% | 5316 (28.9%) |
1066 (53.1%) |
1.47 | 1.30 to 1.66 | <0.001 | 4821 (28.1%) |
1561 (48.1%) |
1.39 | 1.25 to 1.53 | <0.001 |
| Number of THRs performed in calendar year‡ (per 10 additional cases) |
8 (2, 24) |
32 (12, 61) |
1.02 | 0.99 to 1.04 | 0.206 | 7 (2, 22) |
28 (10, 56) |
1.06 | 1.04 to 1.08 | <0.001 |
| Proportion of THRs funded privately | ||||||||||
| 100% NHS funded (ref) | 12 922 (70.2%) |
966 (48.2%) |
1 | – | – | 12 159 (70.8%) |
1729 (53.3%) |
1 | – | – |
| Some or all funded privately | 5482 (29.8%) |
1040 (51.8%) |
1.23 | 1.05 to 1.43 | 0.010 | 5008 (29.2%) |
1514 (46.7%) |
1.09 | 0.96 to 1.23 | 0.187 |
| Number of stem–cup combinations used in calendar year | ||||||||||
| ≤3 (ref) | 14 259 (77.5%) |
589 (29.4%) |
1 | – | – | 13 599 (79.2%) |
1249 (38.5%) |
1 | – | – |
| 4–6 | 3394 (18.4%) |
822 (41.0%) |
4.91 | 4.25 to 5.67 | <0.001 | 2937 (17.1%) |
1279 (39.4%) |
3.77 | 3.36 to 4.23 | <0.001 |
| 7–10 | 675 (3.7%) |
468 (23.3%) |
12.5 | 10.1 to 15.4 | <0.001 | 568 (3.3%) |
575 (17.7%) |
7.21 | 6.01 to 8.67 | <0.001 |
| >10 | 76 (0.4%) |
127 (6.3%) |
27.4 | 17.9 to 41.7 | <0.001 | 63 (0.4%) |
140 (4.3%) |
13.3 | 9.20 to 19.2 | <0.001 |
| Proportion of THRs performed on patients with ASA grade III–V | ||||||||||
| <25% (ref) | 13 244 (72.0%) |
1554 (77.5%) |
1 | – | – | 12 362 (72.0%) |
2436 (75.1%) |
1 | – | – |
| ≥25% | 5160 (28.0%) |
452 (22.5%) |
1.01 | 0.89 to 1.16 | 0.843 | 4805 (28.0%) |
807 (24.9%) |
1.12 | 1.01 to 1.25 | 0.034 |
*Proportions displayed are based on surgeon-calendar years.
†ORs, 95% CI and p values are from logistic regression models adjusted for all exposure variables.
‡Median (lower to upper quartile).
ASA, American Society of Anaesthesiologists; NHS, National Health Service; THR, total hip replacement.