Table 2.
Univariate and Multivariable Cox Regression Analyses for Testing Center Affiliation as Predictor of the Events Freedom‐From‐MMVR and Freedom‐From‐Opioid‐Administration
| End Point and Main Predictor | N Events/N Patients (%) | Hazard Risk, Unadjusted | P Value | Hazard Risk Adjusted for Baseline Factors* | P Value |
|---|---|---|---|---|---|
| Freedom from mandatory ventilator rate | |||||
| Center affiliation | |||||
| Center 1 | 185/203 (87) | Reference | … | Reference | … |
| Center 2 | 38/40 (95) | 1.20 (0.85–1.70) | 0.302 | 0.99 (0.64–1.54) | 0.984 |
| Center 3 | 97/98 (99) | 2.11 (1.65–2.71) | <0.001 | 2.10 (1.62–2.71) | <0.001 |
| Center 4 | 56/56 (100) | 6.93 (5.07–9.46) | <0.001 | 5.08 (3.48–7.41) | <0.001 |
| Center 5 | 87/95 (92) | 1.74 (1.35–2.25) | <0.001 | 1.71 (1.31–2.23) | <0.001 |
| Freedom from opioid administration | |||||
| Center affiliation | |||||
| Center 1 | 168/203 (83) | Reference | Reference | ||
| Center 2 | 30/40 (75) | 0.98 (0.66–1.44) | 0.918 | 0.72 (0.43–1.21) | 0.214 |
| Center 3 | 85/98 (87) | 1.28 (0.99–1.66) | 0.063 | 1.24 (0.94–1.63) | 0.130 |
| Center 4 | 51/56 (91) | 3.00 (2.19–4.11) | <0.001 | 2.92 (2.11–4.04) | <0.001 |
| Center 5 | 77/95 (81) | 1.18 (0.90–1.54) | 0.238 | 1.22 (0.93–1.61) | 0.153 |
Center affiliation was found to be an independent predictor of outcomes. Particularly, being affiliated to Center 3, 4, and 5 predicts a significantly shorter time to freedom‐from‐mandatory‐ventilation compared with Center 1. Being affiliated to Center 4 predicts a significantly shorter time to freedom‐from‐opioid‐administration compared with Center 1. CPB indicates cardiopulmonary bypass; DHCA, deep hypothermic circulatory arrest; ECMO, extracorporeal membrane oxygenation; HLHS, hypoplastic left heart syndrome; MMVR, mandatory mechanical ventilator rate; and POD, postoperative day.
Models are adjusted for age, sex, prematurity, diagnosis (HLHS/not HLHS), shunt type, surgical times (CPB time, DHCA time, aortic clamp time), and ECMO support in the 28 PODs (yes/no).