Table 1.
Baseline characteristics for adults hospitalized between 2006 and 2013 before and after propensity matching, stratified by AKI status
| Characteristic | Before Matching | After Matching | ||||
|---|---|---|---|---|---|---|
| AKI (n=39,153) | No AKI (n=391,006) | D Value | AKI (n=31,245) | No AKI (n=115,696) | D Value | |
| Age, yr | ||||||
| Mean (SD) | 69 (16) | 62 (18) | 0.38 | 69 (15) | 69 (16) | 0.04 |
| Age group, yr, n (%) | 0.37 | 0.03 | ||||
| 18–49 | 4663 (12) | 101,428 (26) | 3552 (11) | 14,205 (12) | ||
| 50–59 | 5463 (14) | 64,391 (17) | 4218 (14) | 15,995 (14) | ||
| 60–69 | 8359 (21) | 77,462 (20) | 6592 (21) | 24,593 (21) | ||
| 70–79 | 10,129 (26) | 75,320 (19) | 8244 (26) | 30,176 (26) | ||
| ≥80 | 10,539 (27) | 72,405 (19) | 8639 (28) | 30,727 (27) | ||
| Sex, n (%) | 0.17 | 0.02 | ||||
| Women | 19,322 (49) | 226,001 (58) | 15,686 (50) | 59,173 (51) | ||
| Men | 19,831 (51) | 165,005 (42) | 15,559 (50) | 56,523 (49) | ||
| Race/ethnicity, n (%) | 0.05 | 0.02 | ||||
| White | 27,941 (71) | 281,584 (72) | 22,756 (73) | 85,386 (74) | ||
| Black | 4506 (12) | 33,981 (9) | 3287 (11) | 11,754 (10) | ||
| Asian/Pacific Islander | 4748 (12) | 48,634 (12) | 3658 (12) | 13,093 (11) | ||
| Native American | 268 (0.7) | 2655 (0.7) | 206 (0.7) | 699 (0.6) | ||
| Other/unknown | 1690 (4) | 24,152 (6) | 1338 (4) | 4764 (4) | ||
| Hispanic ethnicity, n (%) | 5646 (14) | 58,425 (15) | 0.01 | 4462 (14) | 15,495 (13) | 0.03 |
| Current or former smoker, n (%) | 20,027 (51) | 178,832 (46) | 0.13 | 15,833 (51) | 58,126 (50) | 0.01 |
| Prior medical history, n (%) | ||||||
| Coronary heart disease | 3493 (9) | 24,097 (6) | 0.24 | 2690 (9) | 9754 (8) | 0.01 |
| Chronic heart failure | 7643 (20) | 28,762 (7) | 0.68 | 4779 (15) | 14,401 (12) | 0.14 |
| Ischemic stroke | 898 (2) | 10,118 (3) | 0.07 | 773 (3) | 2916 (3) | 0.01 |
| Peripheral artery disease | 2685 (7) | 15,285 (4) | 0.36 | 2071 (7) | 6925 (6) | 0.07 |
| Atrial fibrillation or flutter | 5266 (13) | 35,035 (9) | 0.28 | 4217 (13) | 14,708 (13) | 0.04 |
| Diabetes Mellitus | 15,555 (40) | 83,724 (21) | 0.54 | 11,256 (36) | 38,820 (34) | 0.07 |
| Hypertension | 30,834 (79) | 220,419 (56) | 0.64 | 23,015 (74) | 83,170 (72) | 0.05 |
| Dyslipidemia | 27,273 (70) | 207,974 (53) | 0.43 | 21,314 (68) | 77,189 (67) | 0.04 |
| Cancer | 9157 (23) | 70,462 (18) | 0.20 | 7498 (24) | 27,605 (24) | 0.00 |
| Proteinuria | 15,101 (39) | 77,139 (20) | 0.57 | 10,490 (34) | 32,290 (28) | 0.16 |
| Preadmission eGFR, ml/min per 1.73 m2, n (%) | 0.10 | 0.08 | ||||
| >150 | 38 (0.1) | 249 (0.1) | 32 (0.1) | 53 (0.0) | ||
| 90–150 | 6269 (16) | 80,484 (21) | 5131 (16) | 21,095 (18) | ||
| 60–89 | 11,929 (31) | 125,959 (32) | 10,256 (33) | 41,404 (36) | ||
| 45–59 | 6947 (18) | 41,133 (11) | 5549 (18) | 20,342 (18) | ||
| 30–44 | 6030 (15) | 21,162 (5) | 4301 (14) | 13,106 (11) | ||
| 15–29 | 3164 (8) | 6297 (2) | 1754 (6) | 4107 (4) | ||
| Unknown | 4776 (12) | 115,722 (30) | 4222 (14) | 15,589 (14) | ||
| Preadmission medication use, n (%) | ||||||
| Angiotensin-converting enzyme inhibitor | 16,823 (43) | 100,143 (26) | 0.47 | 12,753 (41) | 45,526 (39) | 0.04 |
| Angiotensin II receptor blocker | 4974 (13) | 31,458 (8) | 0.31 | 3812 (12) | 13,657 (12) | 0.02 |
| Diuretic | 19,823 (51) | 119,145 (31) | 0.52 | 14,998 (48) | 52,503 (45) | 0.06 |
| β-Blocker | 17,353 (44) | 112,333 (29) | 0.41 | 13,179 (42) | 46,701 (40) | 0.05 |
| Calcium channel blocker | 9520 (24) | 53,340 (14) | 0.43 | 6963 (22) | 23,662 (21) | 0.07 |
| Statin | 19,373 (50) | 133,614 (34) | 0.38 | 15,023 (48) | 53,697 (46) | 0.04 |
| Index hospitalization features, n (%) | ||||||
| Coronary bypass surgery | 77 (0.2) | 216 (0.1) | 0.77 | 58 (0.2) | 130 (0.1) | 0.30 |
| Percutaneous coronary intervention | 84 (0.2) | 842 (0.2) | 0.00 | 69 (0.2) | 338 (0.3) | 0.17 |
| Sepsis | 6945 (18) | 22,651 (6) | 0.76 | 3911 (13) | 11,130 (10) | 0.18 |
| Heart failure | 2746 (7) | 7972 (2) | 0.78 | 1832 (6) | 4793 (4) | 0.22 |
| ICU stay, n (%) | 12,273 (31) | 46,576 (12) | 0.74 | 7494 (24) | 23,024 (20) | 0.14 |
| ICU length of stay, h | ||||||
| Median (IQR) | 68 (35–139) | 7 (22–65) | <0.001a | 53 (29–99) | 40 (23–69) | <0.001a |
| Hospital length of stay, d | ||||||
| Median (IQR) | 6 (3–10) | 3 (2–5) | <0.001a | 5 (3–8) | 4 (2–6) | <0.001a |
| Laboratory-based acute physiology score | ||||||
| Median (IQR) | 27 (9–44) | 6 (0–20) | <0.001a | 24 (6–41) | 16 (1–30) | <0.001a |
| Missing, n (%) | 13 (0.0) | 179 (0.0) | 13 (0.0) | 32 (0.0) | ||
| Comorbidity point score | ||||||
| Median (IQR) | 77 (46–114) | 52 (26–86) | <0.001a | 75 (44–111) | 73 (43–108) | <0.001a |
| Missing, n (%) | 415 (1) | 4586 (1) | 366 (1) | 1319 (1) | ||
| Predicted mortality score | ||||||
| Median (IQR) | 3 (1–7) | 1 (0–2) | <0.001a | 2 (1–6) | 2 (1–4) | <0.001a |
| Missing, n (%) | 1446 (4) | 31,026 (8) | 1337 (4) | 5730 (5) | ||
| Predicted mortality score categorical, n (%) | 0.42 | 0.10 | ||||
| <0.1% | 1774 (5) | 69,083 (18) | 1702 (5) | 6442 (6) | ||
| 0.1%–0.4% | 4083 (10) | 90,413 (23) | 3809 (12) | 16,457 (14) | ||
| 0.5%–1.9% | 9422 (24) | 105,600 (27) | 8292 (27) | 35,639 (31) | ||
| 2.0%–4.9% | 9452 (24) | 53,410 (14) | 7503 (24) | 27,364 (24) | ||
| 5.0%–9.9% | 6654 (17) | 24,650 (6) | 4774 (15) | 14,369 (12) | ||
| 10.0%–14.9% | 2772 (7) | 8438 (2) | 1826 (6) | 4881 (4) | ||
| 15.0%–29.9% | 2621 (7) | 6927 (2) | 1590 (5) | 4018 (4) | ||
| ≥30.0% | 929 (2) | 1459 (0.4) | 412 (1) | 796 (0.7) | ||
| Unknown | 1446 (4) | 31,026 (8) | 1337 (4) | 5730 (5) | ||
The D value represents the standardized difference in means or proportions with a value >0.10 being significant. ICU, intensive care unit; IQR, interquartile range.
a
Represents P values and not D values.