Table 2.
Univariate and multivariate Cox regression analysis of association between different factors and failure of core decompression
| Coefficient | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| Hazard Ratio | P value | 95% CI | Hazard Ratio | P value | 95% CI | |
| Ficat stage | ||||||
| Stage I | 1 (reference) | <.001 | 1 (reference) | 1 (reference) | .641 | 1 (reference) |
| Stage II A | .781 | .749 | .171–3.565 | 1.741 | .491 | .359–8.432 |
| Stage II B | 4.749 | .035 | 1.115–20.221 | 1.162 | .849 | .249–5.413 |
| Preoperative Harris score | 1.051 | .190 | .976–1.132 | – | – | – |
| Necrotic location | ||||||
| A | 1 (reference) | <.001 | 1 (reference) | 1 (reference) | .582 | 1 (reference) |
| B | .418 | .538 | .026–6.698 | .306 | .411 | .018–5.163 |
| C1 | 5.242 | .111 | .685–40.097 | 1.231 | .857 | .127–11.896 |
| C2 | 18.644 | .004 | 2.494–139.395 | 1.458 | .752 | .140–15.145 |
| Extent of necrotic lesion | ||||||
| < 15% | 1 (reference) | <.001 | 1 (reference) | 1 (reference) | .001 | 1 (reference) |
| 15–30% | 3.708 | .109 | .747–18.408 | 3.170 | .196 | .551–18.255 |
| > 30% | 32.521 | <.001 | 7.695–137.444 | 22.293 | .001 | 2.506–141.752 |
| Bone marrow edema | 3.814 | <.001 | 1.935–7.518 | 2.188 | .046 | 1.015–4.719 |
| Postoperative work intensity | ||||||
| Grade 0–1 | 1 (reference) | <.001 | 1 (reference) | 1 (reference) | .001 | 1 (reference) |
| Grade 2 | 6.004 | <.001 | 2.768–13.022 | 3.579 | .002 | 1.583–8.092 |
| Grade 3–4 | 6.771 | <.001 | 2.833–16.186 | 5.036 | .001 | 1.863–13.615 |
Variables included in the multivariate model if univariate P value <.05