Table 3.
Multivariable Cox regression models for year all-cause mortality among ECMO survivors
| Variable | Multivariable model | P-value |
|---|---|---|
| HR (95% CI) | ||
| Multivariable model 1 | ||
| Post-ECMO CRD (vs control) | 1.47 (1.17, 1.86) | 0.001 |
| Multivariable model 2 | ||
| Post-ECMO CRD | ||
| Post-ECMO COPD | 1.19 (0.80, 1.79) | 0.391 |
| Post-ECMO Asthma | 1.54 (1.13, 2.11) | 0.007 |
| Post-ECMO ILD | 2.33 (1.05, 6.40) | 0.042 |
| Post-ECMO Lung cancer | 2.21 (0.81, 6.03) | 0.123 |
| Post-ECMO Lung disease due to external agent | 1.07 (0.65, 1.77) | 0.787 |
| Post-ECMO OSA | 3.60 (0.48, 27.08) | 0.214 |
| Post-ECMO TB | 1.29 (0.67, 2.49) | 0.443 |
| Other variables in model 1 | ||
| Age, year | 1.04 (1.04, 1.05) | < 0.001 |
| Sex, male (vs female) | 1.18 (0.98, 1.41) | 0.087 |
| Residence at ECMO treatment | ||
| Capital city (Seoul) | 1 | |
| Other metropolitan city | 0.85 (0.65, 1.12) | 0.250 |
| Other area | 0.95 (0.77, 1.17) | 0.633 |
| Year of ECMO treatment | ||
| 2006 | 1 | |
| 2007 | 0.70 (0.41, 1.18) | 0.176 |
| 2008 | 0.50 (0.30, 0.86) | 0.012 |
| 2009 | 0.55 (0.33, 0.92) | 0.022 |
| 2010 | 0.82 (0.52, 1.30) | 0.406 |
| 2011 | 0.78 (0.50, 1.21) | 0.266 |
| 2012 | 0.78 (0.51, 1.20) | 0.264 |
| 2013 | 0.56 (0.37, 0.87) | 0.009 |
| 2014 | 0.63 (0.42, 0.96) | 0.030 |
| Annual income level at ECMO treatment | ||
| Q1 (Lowest) | 1 | |
| Q2 | 0.94 (0.72, 1.21) | 0.615 |
| Q3 | 0.67 (0.52, 0.86) | 0.001 |
| Q4 (Highest) | 0.84 (0.67, 1.056) | 0.120 |
| Annual case volume of ECMO therapy | ||
| Q1 < 19 | 1 | |
|
Q2: 19–43 Q3: 44–102 |
0.76 (0.58, 0.99) | 0.039 |
| 1.11 (0.88., 1.41) | 0.379 | |
| Q4 > 102 | 0.91 (0.69, 1.21) | 0.525 |
| Charlson comorbidity index, point | 1.05 (1.02, 1.09) | 0.006 |
| Pre-ECMO CRD (vs control) | 1.25 (1.04, 1.49) | 0.019 |
| Underlying disability | ||
| Mild to moderate | 0.86 (0.67, 1.11) | 0.251 |
| Severe | 1.92 (1.53, 2.41) | < 0.001 |
| Length of hospital stay, day | 1.00 (0.99, 1.01) | 0.795 |
| Duration of ECMO therapy, day | 1.03 (1.02, 1.03) | < 0.001 |
| Main diagnosis at ECMO treatment | ||
| Cardiovascular group | 1 | |
| Respiratory group | 1.34 (0.97, 1.85) | 0.076 |
| Others | 2.19 (1.78, 2.68) | < 0.001 |
ECMO extracorporeal membrane oxygenation, HR hazard ratio, CI confidence interval, CRD chronic respiratory disease, COPD chronic obstructive pulmonary disease, ILD interstitial lung disease, OSA osbsructive sleep apnea, TB tuberculosis of lung