Table 1.
The clinicopathological characteristics of the patients
| Variable | Number (%) | Mean (SD) |
|---|---|---|
| Age, year | 53.4 (15.2) | |
| Sex, male | 2032 (66.5) | |
| Residence at ECMO treatment | ||
| Capital city (Seoul) | 770 (25.2) | |
| Other metropolitan city | 631 (20.7) | |
| Other area | 1654 (54.1) | |
| Year of ECMO treatment | ||
| 2006 | 114 (3.7) | |
| 2007 | 144 (4.7) | |
| 2008 | 186 (6.1) | |
| 2009 | 223 (7.3) | |
| 2010 | 271 (8.9) | |
| 2011 | 342 (11.2) | |
| 2012 | 439 (14.4) | |
| 2013 | 580 (19.0) | |
| 2014 | 756 (24.7) | |
| Annual income level at ECMO treatment | ||
| Q1 (Lowest) or unknown | 748 (24.5) | |
| Q2 | 535 (17.5) | |
| Q3 | 763 (25.0) | |
| Q4 (Highest) | 1009 (33.0) | |
| Annual case volume of ECMO therapy | ||
| Q1 < 19 | 508 (16.6) | |
| Q2: 19–43 | 735 (24.1) | |
| Q3: 44–102 | 100 (34.4) | |
| Q4 > 102 | 762 (24.9) | |
| Charlson comorbidity index | 2.8 (2.2) | |
| Underlying disability | ||
| Mild to moderate | 464 (15.2) | |
| Severe | 340 (11.1) | |
| Length of hospital stay, day | 24.6 (15.2) | |
| Duration of ECMO therapy, day | 6.2 (10.3) | |
| 5-year all-cause mortality | 556 (18.2) | |
| Main diagnosis at ECMO treatment | ||
| Cardiovascular group | 1930 (63.2) | |
| Respiratory group | 281 (9.2) | |
| Others | 844 (27.6) |
SD standard deviation, ECMO extracorporeal membrane oxygenation