Table 3.
Results of the logistic regression describing crude univariable model and models adjusting for pre-operative OKS, post-operative factors, and pre-operative demographic characteristics.
| Parameter | Crude Models |
Adjusted model 1 (N = 256,309) |
Adjusted model 2 (N = 187,054) |
|||
|---|---|---|---|---|---|---|
| Odds Ratio (OR) 95% Confidence Interval (CI) | P-value | Odds Ratio (OR) 95% Confidence Interval (CI) | P-value | Odds Ratio (OR) 95% Confidence Interval (CI) | P-value | |
| Preoperative OKS | ||||||
| 0 to 4 | REF | REF | REF | |||
| 5 to 7 | 0.51 (0.50, 0.53) | <0.001 | 0.52 (0.51, 0.54) | <0.001 | 0.56 (0.54, 0.57) | <0.001 |
| 8 to 9 | 0.34 (0.33, 0.35) | <0.001 | 0.35 (0.34, 0.36) | <0.001 | 0.39 (0.38, 0.41) | <0.001 |
| 10 to 12 | 0.22 (0.22, 0.23) | <0.001 | 0.23 (0.22, 0.24) | <0.001 | 0.27 (0.26, 0.28) | <0.001 |
| 13 to 28 | 0.12 (0.12, 0.12) | <0.001 | 0.12 (0.12, 0.13) | <0.001 | 0.16 (0.15, 0.16) | <0.001 |
|
Demographics | ||||||
| Age | ||||||
| <50 | 3.18 (2.96, 3.42) | <0.001 | 2.37 (2.16, 2.61) | <0.001 | ||
| 50–59 | 2.16 (2.09, 2.23) | <0.001 | 1.78 (1.71, 1.86) | <0.001 | ||
| 60–69 | 1.28 (1.25, 1.32) | <0.001 | 1.22 (1.19, 1.26) | <0.001 | ||
| 70–79 | REF | REF | ||||
| 80–84 | 0.90 (0.86, 0.93) | <0.001 | 0.85 (0.80, 0.89) | <0.001 | ||
| 85+ | 0.92 (0.87, 0.98) | 0.006 | 0.75 (0.70, 0.81) | <0.001 | ||
| Sex | ||||||
| Female | REF | REF | ||||
| Male | 0.90 (0.88, 0.92) | <0.001 | 1.14 (1.11, 1.17) | <0.001 | ||
| BMI | ||||||
| Underweight | 1.39 (0.97, 1.98) | 0.069 | 0.98 (0.67, 1.43) | 0.918 | ||
| Normal | REF | REF | ||||
| Overweight | 1.09 (1.04, 1.15) | 0.001 | 1.04 (0.99, 1.10) | 0.154 | ||
| Obese class 1 (30–34.9) | 1.46 (1.39, 1.54) | <0.001 | 1.17 (1.11, 1.24) | <0.001 | ||
| Obese class II (35–39.9) | 1.94 (1.84, 2.05) | <0.001 | 1.28 (1.21, 1.35) | <0.001 | ||
| Obese class 3 (40+) | 2.54 (2.39, 2.70) | <0.001 | 1.27 (1.19, 1.36) | <0.001 | ||
| ASA grade | ||||||
| P1 - Fit and healthy | 0.80 (0.77, 0.84) | <0.001 | 0.82 (0.78, 0.87) | <0.001 | ||
| P2 - Mild disease not incapacitating | REF | REF | ||||
| P3 - Incapacitating systemic disease | 1.51 (1.47, 1.55) | <0.001 | 1.21 (1.17, 1.25) | <0.001 | ||
| P4 – P5 - Life threatening disease/Expected to die within 24 h s | 1.79 (1.50, 2.15) | <0.001 | 1.16 (0.92, 1.46) | 0.215 | ||
| Index of Multiple Deprivation (IMD) quintiles | ||||||
| Most deprived |
REF |
REF |
||||
| 2 | 0.68 (0.66, 0.71) | <0.001 | 0.76 (0.73, 0.80) | <0.001 | ||
| 3 | 0.51 (0.49, 0.52) | <0.001 | 0.62 (0.60, 0.65) | <0.001 | ||
| 4 | 0.42 (0.41, 0.44) | <0.001 | 0.56 (0.54, 0.58) | <0.001 | ||
| Least deprived | 0.36 (0.35, 0.38) | <0.001 | 0.53 (0.50, 0.55) | <0.001 | ||
| 3 month complications | ||||||
| Blood transfusion | 0.83 (0.46, 1.49) | 0.533 | 0.47 (0.26, 0.86) | 0.015 | 0.42 (0.20, 0.86) | 0.018 |
| Acute renal failure | 1.60 (1.33, 1.92) | <0.001 | 1.08 (0.88, 1.31) | 0.455 | 1.11 (0.88, 1.40) | 0.373 |
| Neurovascular injury | 1.45 (0.53, 3.92) | 0.469 | 1.23 (0.41, 3.63) | 0.712 | 1.27 (0.36, 4.43) | 0.709 |
| Mechanical complication of prosthesis | 2.94 (2.60, 3.34) | <0.001 | 1.56 (1.35, 1.80) | <0.001 | 1.51 (1.27, 1.80) | <0.001 |
| Fracture | 1.82 (0.88, 3.76) | 0.106 | 0.92 (0.43, 1.96) | 0.822 | 0.22 (0.05, 0.98) | 0.047 |
| Surgical site infection | 2.01 (1.78, 2.27) | <0.001 | 1.13 (0.99, 1.29) | 0.072 | 1.25 (1.07, 1.47) | 0.004 |
| Wound disruption | 1.77 (1.49, 2.11) | <0.001 | 0.90 (0.74, 1.09) | 0.265 | 0.85 (0.68, 1.06) | 0.141 |
| Urinary tract infection | 1.80 (1.55, 2.10) | <0.001 | 1.05 (0.89, 1.24) | 0.541 | 1.26 (1.04, 1.53) | 0.016 |
| DVT/PE | 1.50 (1.27, 1.77) | <0.001 | 1.13 (0.94, 1.35) | 0.186 | 1.10 (0.89, 1.36) | 0.372 |
| Acute MI | 0.90 (0.65, 1.25) | 0.534 | 0.69 (0.49, 0.97) | 0.034 | 0.81 (0.56, 1.19) | 0.292 |
| Respiratory tract infection | 1.55 (1.34, 1.79) | <0.001 | 0.94 (0.80, 1.10) | 0.461 | 0.97 (0.81, 1.18) | 0.784 |
| Stroke | 1.23 (0.85, 1.77) | 0.27 | 0.96 (0.65, 1.41) | 0.841 | 1.09 (0.68, 1.72) | 0.728 |
| 3 month readmissions | 1.72 (1.68, 1.77) | <0.001 | 1.47 (1.42, 1.52) | <0.001 | 1.49 (1.44, 1.55) | <0.001 |
| 3 month reoperations | 2.07 (1.93, 2.22) | <0.001 | 1.39 (1.27, 1.51) | <0.001 | 1.29 (1.17, 1.43) | <0.001 |
| 3 month revision | 2.87 (2.49, 3.30) | <0.001 | 1.92 (1.64, 2.25) | <0.001 | 1.93 (1.59, 2.33) | <0.001 |
| Surgical complication 1 or greater | 1.28 (1.11, 1.47) | 0.001 | 1.16 (1.00, 1.34) | 0.054 | 1.09 (0.91, 1.30) | 0.366 |
| Length of stay | ||||||
| <2 days | REF | REF | REF | |||
| 2–4 days | 0.84 (0.77, 0.92) | <0.001 | 0.87 (0.80, 0.96) | 0.004 | 0.91 (0.81, 1.01) | 0.087 |
| 4–6 days | 1.05 (0.97, 1.15) | 0.241 | 1.07 (0.97, 1.17) | 0.173 | 1.16 (1.04, 1.29) | 0.009 |
| 6 plus days | 1.63 (1.49, 1.78) | <0.001 | 1.48 (1.35, 1.63) | <0.001 | 1.68 (1.50, 1.87) | <0.001 |