Table 4.
Renal and other outcomes among patients with AKI, weighted cohorts
| Characteristics | COVID-19–positive W = 742 |
No. nonmissing | Influenza-positive W = 743 |
No. nonmissing | P value |
|---|---|---|---|---|---|
| Stage of AKI, n (%)a | 742 | 743 | <0.001 | ||
| 1 | 442 (60) | 613 (82) | |||
| 2 | 110 (15) | 84 (11) | |||
| 3 | 190 (26) | 46 (6) | |||
| Acute dialysis, n (%) | 94 (13) | 742 | 12 (2) | 743 | <0.001 |
| Dialysis at discharge, n (%)b | 58 (8) | 742 | 8 (1) | 743 | <0.001 |
| Peak serum creatinine, mg/dl, mean (SD) | 3.10 (2.40) | 742 | 2.15 (1.13) | 743 | <0.001 |
| Discharge serum creatinine, mg/dl, mean (SD) | 2.05 (1.87) | 742 | 1.45 (0.85) | 743 | <0.001 |
| Death in hospital, n (%)c | 226 (30) | 742 | 26 (3) | 743 | <0.001 |
| Stage 1 | 74 (17) | 442 | 10 (2) | 613 | <0.001 |
| Stage 2 | 38 (35) | 110 | 7 (8) | 84 | <0.001 |
| Stage 3 | 113 (60) | 190 | 10 (21) | 46 | <0.001 |
| Death within 90 days of peak serum creatinine, n (%)c | 263 (35) | 742 | 70 (9) | 743 | <0.001 |
| Stage 1 AKI | 100 (23) | 442 | 46 (7) | 613 | <0.001 |
| Stage 2 AKI | 42 (38) | 110 | 12 (14) | 84 | <0.001 |
| Stage 3 AKI | 120 (63) | 190 | 12 (27) | 46 | <0.001 |
AKI, acute kidney injury; COVID-19, coronavirus disease 2019; W, sum of the patient weights.
The W value can be thought of as the effective number of patients in the weighted cohort created by the matching weights. The entire cohort of 2500 patients with AKI was used with patients receiving weights greater than 0 and less than or equal to 1, yielding a sum of weights equal to 1485.
a
Kidney Disease: Improving Global Outcomes (KDIGO)–modified criteria.
b
Defined as receiving dialysis within 48 hours of discharge.
c
Mortality rates stratified by AKI stage and COVID-19 versus influenza diagnosis.