Table 1.
Patient characteristics of the study population
| Characteristics | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | Total | P-value | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| No. of cases/person-year | 2,194/825,502 | 2,256/820,204 | 2,398/842,444 | 2,672/832,170 | 2,921/837,177 | 2,887/846,853 | 3,639/855,428 | 3,915/863,820 | 22,882/6,723,598 | ||
| Age group (yr) | <0.001 | ||||||||||
| 15–64 | 972 (44.3) | 978 (43.4) | 957 (39.9) | 1,084 (40.6) | 1,172 (40.1) | 1,089 (37.7) | 1,307 (35.9) | 1,295 (33.1) | 8,854 (38.7) | ||
| 65–74 | 573 (26.1) | 588 (26.1) | 626 (26.1) | 670 (25.1) | 747 (25.6) | 698 (24.2) | 818 (22.5) | 901 (23.0) | 5,621 (24.6) | ||
| 75–84 | 499 (22.7) | 522 (23.1) | 614 (25.6) | 658 (24.6) | 726 (24.9) | 793 (27.5) | 1,037 (28.5) | 1,207 (30.8) | 6,056 (26.5) | ||
| ≥ 85 | 150 (6.8) | 168 (7.4) | 201 (8.4) | 260 (9.7) | 276 (9.4) | 307 (10.6) | 477 (13.1) | 512 (13.1) | 2,351 (10.3) | ||
| Sex, male | 1,273 (58.0) | 1,239 (54.9) | 1,352 (56.4) | 1,519 (56.8) | 1,622 (55.5) | 1,654 (57.3) | 1,948 (53.5) | 2,112 (53.9) | 12,719 (55.6) | 0.003 | |
| Comorbidities | |||||||||||
| Chronic pulmonary disease | 473 (21.6) | 500 (22.2) | 505 (21.1) | 585 (21.9) | 636 (21.8) | 600 (20.8) | 723 (19.9) | 811 (20.7) | 4,833 (21.1) | 0.384 | |
| Neoplasm | 230 (10.5) | 246 (10.9) | 249 (10.4) | 297 (11.1) | 289 (9.9) | 281 (9.7) | 378 (10.4) | 453 (11.6) | 2,423 (10.6) | 0.251 | |
| Chronic liver disease | 151 (6.9) | 119 (5.3) | 144 (6.0) | 163 (6.1) | 207 (7.1) | 162 (5.6) | 202 (5.6) | 234 (6.0) | 1,382 (6.0) | 0.067 | |
| Renal disease | 55 (2.5) | 49 (2.2) | 74 (3.1) | 94 (3.5) | 105 (3.6) | 90 (3.1) | 151 (4.1) | 198 (5.1) | 816 (3.6) | < 0.001 | |
| Diabetes melitus | 173 (7.9) | 193 (8.6) | 246 (10.3) | 287 (10.7) | 322 (11.0) | 342 (11.8) | 410 (11.3) | 554 (14.2) | 2,527 (11.0) | < 0.001 | |
| Peripheral vascular disease | 31 (1.4) | 30 (1.3) | 34 (1.4) | 40 (1.5) | 46 (1.6) | 57 (2.0) | 62 (1.7) | 89 (2.3) | 389 (1.7) | 0.051 | |
| Rheumatological disease | 8 (0.4) | 24 (1.1) | 12 (0.5) | 16 (0.6) | 16 (0.5) | 28 (1.0) | 22 (0.6) | 32 (0.8) | 158 (0.7) | 0.036 | |
| Charlson comorbidity index | < 0.001 | ||||||||||
| 0 | 1,170 (53.3) | 1,160 (51.4) | 1,224 (51.0) | 1,318 (49.3) | 1,420 (48.6) | 1,419 (49.2) | 1,783 (49.0) | 1,773 (45.3) | 11,267 (49.2) | ||
| 1 | 544 (24.8) | 584 (25.9) | 580 (24.2) | 613 (22.9) | 739 (25.3) | 723 (25.0) | 880 (24.2) | 940 (24.0) | 5,603 (24.5) | ||
| 2 | 220 (10.0) | 246 (10.9) | 285 (11.9) | 347 (13.0) | 361 (12.4) | 372 (12.9) | 487 (13.4) | 539 (13.8) | 2,857 (12.5) | ||
| >2 | 260 (11.9) | 266 (11.8) | 309 (12.9) | 394 (14.7) | 401 (13.7) | 373 (12.9) | 489 (13.4) | 663 (16.9) | 3,155 (13.8) | ||
| Presented to emergency room | 1,274 (58.1) | 1,329 (58.9) | 1,425 (59.4) | 1,492 (55.8) | 1,618 (55.4) | 1,658 (57.4) | 2,070 (56.9) | 2,262 (57.8) | 13,128 (57.4) | 0.041 | |
| Medical department | 1,520 (69.3) | 1,560 (69.1) | 1,686 (70.3) | 1,884 (70.5) | 2,059 (70.5) | 2,018 (69.9) | 2,630 (72.3) | 2,855 (72.9) | 16,212 (70.9) | 0.007 | |
| Surgical department | 668 (30.4) | 694 (30.8) | 708 (29.5) | 782 (29.3) | 855 (29.3) | 865 (30.0) | 1,002 (27.5) | 1,053 (26.9) | 6,627 (29.0) | 0.006 | |
| Income level | < 0.001 | ||||||||||
| Lower | 376 (17.1) | 324 (14.4) | 398 (16.6) | 502 (18.8) | 518 (17.7) | 446 (15.4) | 1,064 (29.2) | 1,102 (28.1) | 4,730 (20.7) | ||
| Lower-middle | 326 (14.9) | 323 (14.3) | 332 (13.8) | 344 (12.9) | 398 (13.6) | 415 (14.4) | 392 (10.8) | 432 (11.0) | 2,962 (12.9) | ||
| Middle | 372 (17.0) | 387 (17.2) | 422 (17.6) | 492 (18.4) | 509 (17.4) | 490 (17.0) | 496 (13.6) | 472 (12.1) | 3,640 (15.9) | ||
| Upper-middle | 475 (21.6) | 490 (21.7) | 516 (21.5) | 533 (19.9) | 594 (20.3) | 547 (18.9) | 619 (17.0) | 670 (17.1) | 4,444 (19.4) | ||
| Upper | 645 (29.4) | 732 (32.4) | 730 (30.4) | 801 (30.0) | 902 (30.9) | 989 (34.3) | 1,068 (29.3) | 1,239 (31.6) | 7,106 (31.1) | ||
| Hospital size (no. of beds) | < 0.001 | ||||||||||
| < 100 | 59 (2.7) | 75 (3.3) | 59 (2.5) | 89 (3.3) | 98 (3.4) | 100 (3.5) | 74 (2.0) | 72 (1.8) | 626 (2.7) | ||
| 100–299 | 399 (18.2) | 417 (18.5) | 451 (18.8) | 531 (19.9) | 580 (19.9) | 650 (22.5) | 808 (22.2) | 801 (20.5) | 4,637 (20.3) | ||
| 300–599 | 501 (22.8) | 418 (18.5) | 528 (22.0) | 585 (21.9) | 618 (21.2) | 650 (22.5) | 889 (24.4) | 971 (24.8) | 5,160 (22.6) | ||
| 600–999 | 645 (29.4) | 668 (29.6) | 739 (30.8) | 779 (29.2) | 856 (29.3) | 813 (28.2) | 1,002 (27.5) | 1,136 (29.0) | 6,638 (29.0) | ||
| ≥ 1,000 | 590 (26.9) | 678 (30.1) | 621 (25.9) | 688 (25.7) | 769 (26.3) | 674 (23.3) | 866 (23.8) | 935 (23.9) | 5,821 (25.4) | ||
| Organ dysfunction | |||||||||||
| Respiratory | 1,163 (53.0) | 1,172 (52.0) | 1,286 (53.6) | 1,400 (52.4) | 1,482 (50.7) | 1,459 (50.5) | 1,851 (50.9) | 2,041 (52.1) | 11,854 (51.8) | 0.218 | |
| Hemodynamic | 1,024 (46.7) | 1,075 (47.7) | 1,160 (48.4) | 1,251 (46.8) | 1,393 (47.7) | 1,359 (47.1) | 1,731 (47.6) | 1,799 (46.0) | 10,792 (47.2) | 0.679 | |
| Sepsis-induced cardiomyopathy | 5 (0.2) | 7 (0.3) | 11 (0.5) | 10 (0.4) | 20 (0.7) | 18 (0.6) | 25 (0.7) | 46 (1.2) | 142 (0.6) | < 0.001 | |
| Hematologic | 266 (12.1) | 231 (10.2) | 257 (10.7) | 275 (10.3) | 309 (10.6) | 299 (10.4) | 356 (9.8) | 391 (10.0) | 2,384 (10.4) | 0.210 | |
| Renal | 261 (11.9) | 301 (13.3) | 303 (12.6) | 327 (12.2) | 363 (12.4) | 374 (13.0) | 479 (13.2) | 584 (14.9) | 2,992 (13.1) | 0.013 | |
| Hepatic | 198 (9.0) | 167 (7.4) | 176 (7.3) | 230 (8.6) | 206 (7.1) | 188 (6.5) | 194 (5.3) | 159 (4.1) | 1,518 (6.6) | < 0.001 | |
| Metabolic | 29 (1.3) | 27 (1.2) | 37 (1.5) | 39 (1.5) | 33 (1.1) | 37 (1.3) | 61 (1.7) | 65 (1.7) | 328 (1.4) | 0.469 | |
| Neurologic | 115 (5.2) | 121 (5.4) | 130 (5.4) | 179 (6.7) | 180 (6.2) | 182 (6.3) | 275 (7.6) | 331 (8.5) | 1,513 (6.6) | < 0.001 | |
| No. of organ dysfunctions | 0.351 | ||||||||||
| 1 | 1,585 (72.2) | 1,651 (73.2) | 1,701 (70.9) | 1,962 (73.4) | 2,138 (73.2) | 2,147 (74.4) | 2,670 (73.4) | 2,846 (72.7) | 16,700 (73.0) | ||
| 2 | 420 (19.1) | 423 (18.8) | 495 (20.6) | 481 (18.0) | 559 (19.1) | 519 (18.0) | 699 (19.2) | 747 (19.1) | 4,343 (19.0) | ||
| 3 | 134 (6.1) | 132 (5.9) | 152 (6.3) | 152 (5.7) | 173 (5.9) | 163 (5.6) | 193 (5.3) | 229 (5.8) | 1,328 (5.8) | ||
| ≥4 | 55 (2.5) | 50 (2.2) | 50 (2.1) | 77 (2.9) | 51 (1.7) | 58 (2.0) | 77 (2.1) | 93 (2.4) | 511 (2.2) | ||
| Site of infection | 0.001 | ||||||||||
| Respiratory | 1,122 (51.1) | 1,189 (52.7) | 1,307 (54.5) | 1,431 (53.6) | 1,529 (52.3) | 1,559 (54.0) | 1,951 (53.6) | 2,167 (55.4) | 12,255 (53.6) | ||
| CNS | 14 (0.6) | 19 (0.8) | 20 (0.8) | 12 (0.4) | 18 (0.6) | 30 (1.0) | 18 (0.5) | 19 (0.5) | 150 (0.7) | ||
| Gastrointestinal | 444 (20.2) | 445 (19.7) | 441 (18.4) | 508 (19.0) | 570 (19.5) | 541 (18.7) | 714 (19.6) | 720 (18.4) | 4,383 (19.2) | ||
| Genitourinary | 122 (5.6) | 147 (6.5) | 183 (7.6) | 188 (7.0) | 202 (6.9) | 218 (7.6) | 259 (7.1) | 310 (7.9) | 1,629 (7.1) | ||
| Musculoskeletal, skin and soft tissue 114 (5.2) | 87 (3.9) | 99 (4.1) | 130 (4.9) | 154 (5.3) | 146 (5.1) | 164 (4.5) | 174 (4.4) | 1,068 (4.7) | |||
| Endocarditis | 5 (0.2) | 7 (0.3) | 4 (0.2) | 9 (0.3) | 8 (0.3) | 8 (0.3) | 11 (0.3) | 11 (0.3) | 63 (0.3) | ||
| Device-related | 16 (0.7) | 5 (0.2) | 9 (0.4) | 14 (0.5) | 12 (0.4) | 7 (0.2) | 15 (0.4) | 24 (0.6) | 102 (0.4) | ||
| Unspecified | 357 (16.3) | 357 (15.8) | 335 (14.0) | 380 (14.2) | 428 (14.7) | 378 (13.1) | 507 (13.9) | 490 (12.5) | 3,232 (14.1) | ||
| Septic shock | 1,014 (46.2) | 1,063 (47.1) | 1,146 (47.8) | 1,227 (45.9) | 1,367 (46.8) | 1,320 (45.7) | 1,694 (46.6) | 1,739 (44.4) | 10,570 (46.2) | 0.242 | |
| Length of stay | |||||||||||
| Median (IQR) | 12.0 (7.0-24.0) | 13.0 (7.0-26.0) | 14.0 (7.0-26.0) | 13.0 (7.0-27.0) | 12.0 (7.0-25.0) | 13.0 (7.0-26.0) | 13.0 (7.0-28.0) | 14.0 (7.0-29.0) | 13.0 (7.0-26.0) | < 0.001 | |
| Mean ± SD | 24.7 ± 44.5 | 27.0 ± 48.3 | 26.6 ± 43.1 | 27.3 ± 48.8 | 25.6 ± 47.2 | 29.2 ± 55.4 | 32.5 ± 62.3 | 36.3 ± 69.7 | 29.3 ± 55.0 | ||
| Cost (10,000 KRW) | |||||||||||
| Median (IQR) | 209.8 (113.9-449.5) | 240.5 (131.1-539.8) | 283.5 (144.8-604.8) | 263.8 (140.6-633.2) | 264.8 (144.3-617.5) | 292.6 (151.2-645.9) | 306.3 (158.0-675.1) | 309.9 (163.1-731.5) | 276 (144.2-621.8) | < 0.001 | |
| Mean ± SD | 425.3 ± 628.1 | 513.9 ± 804.3 | 548.6 ± 801.2 | 574.2 ± 959.5 | 593.9 ± 951.3 | 620.2 ± 1,002.5 | 681.2 ± 1,079.9 | 743.3 ± 1,226.6 | 605.6 ± 984.8 | ||
| ICU admission | 747 (34.0) | 722 (32.0) | 806 (33.6) | 792 (29.6) | 896 (30.7) | 821 (28.4) | 1,139 (31.3) | 1,208 (30.9) | 7,131 (31.2) | < 0.001 | |
| 6-month mortality | 582 (26.5) | 628 (27.8) | 696 (29.0) | 790 (29.6) | 831 (28.4) | 881 (30.5) | 1,089 (29.9) | 1,243 (31.7) | 6,740 (29.5) | 0.001 | |
Values are presented as number (%) unless otherwise indicated.
CNS, central nervous system; IQR, interquartile range; SD, standard deviation; KRW, Korean won; ICU, intensive care unit.