Table 4.
Multivariable Cox proportional hazards models of patient survival among adult lung transplant recipients showing geographic distance to donor center interacting with center volume and stratifying the baseline hazard by transplant center (n = 12 447)
| Variable | HR (95% CI) | p-value |
|---|---|---|
| Distance to donor center (Hundreds of kilometers)1 | 0.995 (0.984–1.006) | 0.380 |
| Center LTx volume (Hundreds of transplants)2 | ||
| Interaction with distance to donor center | 1.002 (0.998–1.006) | 0.322 |
| Male recipient | 1.129 (1.055–1.207) | <0.001 |
| Male donor | 0.947 (0.884–1.015) | 0.123 |
| Race of recipient | ||
| White | Ref | |
| Black | 1.015 (0.905–1.138) | 0.802 |
| Other | 0.892 (0.789–1.008) | 0.066 |
| Race of donor | ||
| White | Ref | |
| Black | 1.162 (1.077–1.254) | <0.001 |
| Other | 1.053 (0.970–1.144) | 0.215 |
| Bilateral LTx | 0.768 (0.715–0.825) | <0.001 |
| Diagnosis | ||
| PPH | 1.379 (1.080–1.760) | 0.010 |
| CF | 1.277 (1.089–1.497) | 0.003 |
| IPF | Ref | |
| COPD | 1.002 (0.893–1.124) | 0.974 |
| Sarcoidosis | 0.939 (0.779–1.131) | 0.506 |
| A1AD | 0.988 (0.803–1.216) | 0.911 |
| Other | 1.126 (1.010–1.254) | 0.032 |
| ECMO | 1.175 (0.892–1.547) | 0.252 |
| Mechanical ventilation | 1.345 (1.156–1.564) | <0.001 |
| Donor infection | 0.991 (0.932–1.054) | 0.781 |
| CMV matching | ||
| R−D− | Ref | |
| R+D− | 1.019 (0.923–1.126) | 0.706 |
| R−D+ | 1.281 (1.167–1.407) | <0.001 |
| R+D+ | 1.090 (0.995–1.193) | 0.064 |
| Donor cause of death | ||
| Head trauma | Ref | |
| Cerebrovascular | 0.997 (0.921–1.079) | 0.931 |
| Other | 1.023 (0.939–1.115) | 0.603 |
| Age (years) | 1.013 (1.010–1.017) | <0.001 |
| Year of transplant | 0.998 (0.984–1.012) | 0.807 |
| Creatinine (mg/dL) | 1.092 (1.040–1.146) | <0.001 |
| BMI (kg/m2) | 1.002 (0.995–1.010) | 0.588 |
| Final LAS | 1.001 (0.998–1.004) | 0.646 |
| FEV1 (% predicted) | 1.001 (0.999–1.004) | 0.366 |
| FVC (% predicted) | 0.998 (0.995–1.000) | 0.094 |
| O2 requirement (L/min) | 1.008 (0.999–1.018) | 0.087 |
| Six-minute walk distance (m) | 0.999 (0.999–1.000) | <0.001 |
| Mean PAP (mmHg) | 1.002 (0.998–1.005) | 0.348 |
| Donor age (years) | 1.004 (1.001–1.006) | 0.003 |
| Donor PaO2 (mmHg) | 1.000 (1.000–1.000) | 0.219 |
A1AD, α1-antitrypsin deficiency; CI, confidence interval; CF, cystic fibrosis; CMV, cytomegalovirus; COPD, chronic obstructive pulmonary disease; D, donor; ECMO, extracorporeal membrane oxygenation; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; HR, hazard ratio; IPF, idiopathic pulmonary fibrosis; LAS, lung allocation score; LTx, lung transplant; PAP, pulmonary artery pressure; PaO2, partial pressure of oxygen; PPH, primary pulmonary hypertension; R, recipient; Ref, reference.
Quadratic term not included because the quadratic specification did not improve model fit.
Total lung transplants performed in 2005–2015, centered at 150.