Table 1.
Baseline characteristics of participants used to derive a simple risk score for predicting severe cisplatin associated acute kidney injury. Values are number (percentage) unless stated otherwise
| Characteristics | All patients (n=24 717) | Derivation cohort (n=11 766) | Validation cohort (n=12 951) | |
|---|---|---|---|---|
| Personal information | ||||
| Median (IQR) age (years) | 60 (50-67) | 59 (50-67) | 60 (50-67) | |
| Male sex | 14 275 (57.8) | 6935 (58.9) | 7340 (56.7) | |
| Race: | ||||
| White | 19 378 (78.4) | 9495 (80.7) | 9,883 (76.3) | |
| Black | 1673 (6.8) | 793 (6.7) | 880 (6.8) | |
| Asian/Pacific Islander | 1449 (5.9) | 803 (6.8) | 646 (5.0) | |
| Other/Unknown | 2217 (9.0) | 675 (5.7) | 1542 (11.9) | |
| Ethnicity: | ||||
| Non-Hispanic | 19 597 (79.3) | 9532 (81.0) | 10 065 (77.7) | |
| Hispanic | 2045 (8.3) | 708 (6.0) | 1337 (10.3) | |
| Median (IQR) body mass index | 26.8 (23.5-30.6) | 26.7 (23.5-30.4) | 27.0 (23.6-30.9) | |
| Coexisting conditions | ||||
| Diabetes mellitus | 3259 (13.2) | 1426 (12.1) | 1833 (14.2) | |
| Hypertension | 7223 (29.2) | 2900 (24.6) | 4323 (33.4) | |
| Chronic obstructive pulmonary disease | 2368 (9.6) | 1516 (12.9) | 852 (6.6) | |
| Current or former smoker | 10 810 (43.7) | 6762 (57.5) | 4048 (31.3) | |
| Congestive heart failure | 462 (1.9) | 91 (0.8) | 371 (2.9) | |
| Cirrhosis | 247 (1.0) | 67 (0.6) | 180 (1.4) | |
| Baseline eGFR (mL/min/1.73m2)*: | ||||
| Median (IQR) eGFR | 91 (76-102) | 90 (75-101) | 92 (77-104) | |
| ≥90 | 12 856 (52.0) | 5844 (49.7) | 7012 (54.1) | |
| 60-89 | 9752 (39.5) | 4908 (41.7) | 4844 (37.4) | |
| 45-59 | 1763 (7.1) | 865 (7.4) | 898 (6.9) | |
| <45 | 346 (1.4) | 149 (1.3) | 197 (1.5) | |
| Laboratory values (median (IQR)) | ||||
| WBC count (x109/L) | 7.1 (5.6-9.2) | 7.1 (5.6-9.1) | 7.1 (5.6-9.2) | |
| Hemoglobin (g/L) | 128 (113-140) | 128 (114-140) | 127 (112-140) | |
| Platelet count (x109/L) | 250 (200-314) | 255 (204-322) | 245 (197-306) | |
| Creatinine (µmol/L) | 72.5 (61.9-88.4) | 79.6 (61.9-88.4) | 72.5 (60.1-86.6) | |
| Magnesium (mmol/L) | 0.8 (0.8-0.9) | 0.9 (0.8-0.9) | 0.8 (0.8-0.9) | |
| Calcium (mmol/L) | 2.3 (2.3-2.4) | 2.3 (2.3-2.4) | 2.4 (2.3-2.4) | |
| Albumin (g/L) | 41 (37-43) | 41 (37-44) | 41 (37-43) | |
| Chemotherapy | ||||
| Median (IQR) cisplatin dose (mg) | 75 (55-130) | 90 (60-160) | 70 (47-97) | |
| Nephrotoxic chemotherapy† | 2064 (8.4) | 1043 (8.9) | 1021 (7.9) | |
| Pemetrexed | 935 (3.8) | 673 (5.7) | 262 (2.0) | |
| Immune checkpoint inhibitors | 325 (1.3) | 139 (1.2) | 186 (1.4) | |
| Cetuximab | 46 (0.2) | 0 (0.0) | 46 (0.4) | |
| Ifosfamide | 798 (3.2) | 257 (2.2) | 541 (4.2) | |
Missing data: In the overall cohort (n=24 717), ethnicity was missing in 3075 (12.4%), body mass index in 3889 (15.7%), smoking in 1639 (6.6%), WBC count in 275 (1.1%), hemoglobin in 270 (1.1%), platelet count in 470 (1.9%), serum magnesium in 6577 (26.6%), serum calcium in 3356 (13.6%), serum albumin in 1938 (7.8%), cisplatin dose in 83 (0.3%), and immune checkpoint inhibitors in 5 (<0.1%).
eGFR=estimated glomerular infiltration rate; IQR=interquartile range; WBC=white blood cell.
eGFR was calculated using the 2021 Chronic Kidney Disease Epidemiology Collaboration equation.19
Receipt of concomitant nephrotoxic chemotherapy was assessed within 30 days before receipt of cisplatin, and included pemetrexed, immune checkpoint inhibitors (pembrolizumab, nivolumab, atezolizumab, durvalumab, avelumab, ipilimumab, and cemiplimab), cetuximab, and ifosfamide.