Table 5.
Summary of Cox regression analysis of time-to-first re-operations after primary DD surgery.
| Predictors | Hazard ratio (HR), 95% CI for all primary DD operations |
|---|---|
| Age at time of operation | 0.967 (0.966–0.969)a |
| Gender | |
| Women | 1(base) |
| Men | 0.951 (0.911–0.995) |
| Type of primary surgery | |
| PNF | 1 (base) |
| LF | 0.419 (0.399–0.440) |
| DF | 0.388 (0.346–0.434) |
| Grouped Charlson comorbidity index | |
| GCCI (2 or more) | 1 (base) |
| GCCI (1) | 1.085 (1.012–1.164) |
| GCCI (0) | 1.175 (1.107–1.248) |
| Index of multiple deprivation deciles | |
| Most deprived 10% | 1 (base) |
| More deprived 10–20% | 1.051 (0.954–1.159) |
| More deprived 20–30% | 1.103 (1.004–1.211) |
| More deprived 30–40% | 1.103 (1.002–1.206) |
| More deprived 40–50% | 1.090 (0.995–1.192) |
| Less deprived 40–50% | 1.135 (1.036–1.238) |
| Less deprived 30–40% | 1.129 (1.031–1.231) |
| Less deprived 20–30% | 1.188 (1.088–1.295) |
| Less deprived 10–20% | 1.186 (1.085–1.293) |
| Least deprived 10% | 1.186 (1.083–1.294) |
Values in bold type represent statistically significant increased risks.
aPer increase of 1 year from age 18 (base).