Appendix Table 1.
Cox Regression Model for Predictors of Length of Hospital Stay
| N | Hazard ratio (95% CI) | P | |
|---|---|---|---|
| Center | 372 | 0.004 | |
| Demographics | |||
| Gender | |||
| Male | 238 | 1.05 (0.85, 1.30) | 0.62 |
| Female | 135 | Ref grp | |
| Hispanic | |||
| Yes | 69 | 1.27 (0.97, 1.65) | 0.08 |
| No | 300 | Ref grp | |
| Race | 0.27 | ||
| White | 304 | Ref grp | |
| Black | 51 | 0.79 (0.59, 1.06) | |
| Other | 14 | 1.09 (0.63, 1.88) | |
| SES score | 360 | 0.98 (0.96, 1.00) | 0.09 |
| Genetic syndrome | 0.02 | ||
| Yes | 91 | Ref grp | |
| No | 196 | 0.79 (0.59, 1.06) | |
| Unknown | 85 | 1.09 (0.63, 1.88) | |
| Anatomy | |||
| HLHS | 0.88 | ||
| Yes | 333 | 1.03 (0.74, 1.43) | |
| No | 40 | Ref grp | |
| Clinical diagnoses at time of stage II procedure | |||
| Branch PA stenosis | 0.16 | ||
| Yes | 97 | 1.18 (0.94, 1.49) | |
| No | 274 | Ref grp | |
| AVVR | 0.003 | ||
| Yes | 37 | 1.69 (1.20, 2.39) | |
| No | 334 | Ref grp | |
| Aortic arch obstruction | 0.53 | ||
| Yes | 28 | 1.13 (0.77, 1.67) | |
| No | 343 | Ref grp | |
| Norwood Hospitalization | |||
| Shunt type at the end of Norwood | 0.14 | ||
| MBTS | 164 | Ref grp | |
| RVPAS | 208 | 1.17 (0.95, 1.44) | |
| Log transformed Norwood LOS | 372 | 1.80 (1.53, 2.13) | <.001 |
| Discharge after Norwood operation | <.001 | ||
| No | 13 | 4.13 (2.29, 7.44) | |
| Yes | 359 | Ref grp | |
| On ECMO | 0.03 | ||
| Yes | 25 | 1.64 (1.07, 2.52) | |
| No | 348 | Ref grp | |
| Inter-stage Interventions | |||
| ECMO | |||
| Yes | 5 | 1.42 (0.58, 3.43) | 0.44 |
| No | 368 | Ref grp | |
| Inter-stage intervention on Aorta: | 0.543 | ||
| Yes | 62 | 1.09 (0.83, 1.43) | |
| No | 310 | Ref grp | |
| Inter-stage intervention on PA: | 0.95 | ||
| Yes | 10 | 1.02 (0.54, 1.91) | |
| No | 362 | Ref grp | |
| Inter-stage intervention on atrial septum: | 0.66 | ||
| Yes | 10 | 0.87 (0.46, 1.63) | |
| No | 362 | Ref grp | |
| Other Inter-stage intervention: | 0.89 | ||
| Yes | 31 | 1.03 (0.71, 1.48) | |
| No | 341 | Ref grp | |
| Pre-stage II Cath/Echo | |||
| RVFAC (range 0 to 1) | 344 | 0.93 (0.87, 1.003) per .05 unit increase | 0.06 |
| ≥Moderate Tricuspid valve regurgitation | 365 | ||
| Yes | 86 | 1.52 (1.19, 1.95) | 0.001 |
| No | 279 | Ref grp | |
| Pre-stage II Catheterization Hemodynamics | |||
| Ventricular end diastolic pressure from Cath, mmHg | 348 | 1.03 (1.00, 1.06) | 0.08 |
| Pulmonary vascular resistance, Wood units | 253 | 1.21 (1.07, 1.35) | 0.001 |
| Pre-Stage II Angiography | |||
| Severity of LPA stenosis | 325 | 1.00 (0.99, 1.00) | 0.64 |
| <15% | 196 | 1.16 (0.72, 1.89) | 0.73 |
| 15–<35% | 75 | 1.04 (0.62, 1.74) | |
| 35–<50% | 36 | 1.25 (0.71, 2.21) | |
| ≥50% | 18 | Ref grp | |
| Severity of RPA stenosis | 325 | 1.16 (0.72, 1.89) | 0.13 |
| <15% | 175 | 1.04 (0.62, 1.74) | 0.21 |
| 15–<35% | 80 | 1.25 (0.71, 2.21) | |
| 35–<50% | 40 | 1.16 (0.72, 1.89) | |
| ≥50% | 30 | Ref grp | |
| Total lower lobe index, mm2/M2 1 | 322 | 0.94 (0.89, 0.989) per a 50-unit increase | 0.02 |
| Nakata Index | 322 | 0.96 (0.90, 1.03) Per a 50-unit increase | 0.27 |
| At stage II | |||
| Reasons for timing of stage II procedure | <.001 | ||
| Elective | 252 | 0.61 (0.49, 0.77) | |
| Non-elective | 120 | Ref grp | |
| Age at stage II | 0.96 (0.90, 1.01) | 0.11 | |
| Weight –age-z on pre-stage II Echo | 368 | 0.89 (0.81, 0.97) | 0.009 |
| Type of stage II | 0.81 | ||
| Bidirectional cavopulmonary shunt | 234 | 0.85 (0.40, 1.80) | |
| Hemi-Fontan | 91 | 0.84 (0.39, 1.81) | |
| Bidirectional cavopulmonary anastomoses | 40 | 0.73 (0.33, 1.64) | |
| Other | 7 | Ref grp | |
| Total CPB time, per 10 min increase | 370 | 1.05 (1.02, 1.08) | <.001 |
| On DHCA | 371 | 0.56 | |
| Yes | 1.07 (0.85, 1.35) | ||
| No | Ref grp | ||
| Concurrent procedures: PA repair | 372 | 0.01 | |
| Yes | 133 | 1.32 (1.06, 1.63) | |
| No | 239 | Ref grp | |
| Concurrent procedures: Aortic Arch repair | 372 | 0.09 | |
| Yes (n=22) | 22 | 1.46 (0.95, 2.25) | |
| No (n=350) | 350 | Ref grp | |
| Concurrent procedures: AV valve repair | 372 | 0.03 | |
| Yes | 34 | 1.49 (1.04, 2.12) | |
| No | 338 | Ref grp | |
| Concurrent procedures: Aortic valve repair | 372 | 0.48 | |
| Yes | 9 | 0.79 (0.41, 1.53) | |
| No | 363 | Ref grp | |
| Concurrent: ASD | 372 | 0.73 | |
| Yes | 16 | 0.92 (0.55, 1.51) | |
| No | 356 | Ref grp |
SES: socio-economic status; HLHS: hypoplastic left heart syndrome; PA: pulmonary artery; AVVR: atrioventricular valve regurgitation; MBTS: modified Blalock-Taussig shunt; RVPAS: right ventricle-to-pulmonary artery shunt; LOS: length of hospital stay; ECMO: extracorporeal membrane oxygenation; Cath: catheterization; Echo: echocardiogram; RVFAC: right ventricle fractional area change; LPA: left pulmonary artery; RPA: right pulmonary artery; CPB: cardiopulmonary bypass; DHCA: deep hypothermic circulatory arrest; AV: atrioventricular; ASD: atrial septal defect; Ref grp: reference group; CI: confidence interval
1
Total lower lobe index was defined as (3.14*[right lower lobe diameter/2]2 + 3.14*[left lower lobe diameter/2]2)/BSA