Table 4.
Laboratory characteristics of patients on hemodialysis with and without an undetected severe acute respiratory syndrome coronavirus 2 infection identified in the subsequent ≥3 d
| Variable | Unaffected Patients, Mean±SD, N | Coronavirus Disease 2019+, Patients, Mean±SD, N |
| Number of patients on HD | 29,324 | 11,166 |
| Albumin (g/dl)a | 3.79±0.40; 13,723 | 3.69±0.46; 5252 |
| Change in albumin (g/dl)b | −0.002±0.25; 13,139 | −0.03±0.27; 5012 |
| Creatinine (mg/dl)a | 8.42±3.06; 13,323 | 8.41±3.14; 5113 |
| Change in creatinine (mg/dl)b | 0.08±1.40; 12,711 | 0.16±1.52; 4860 |
| Bicarbonate (mmol/L)a | 24.24±3.05; 13,395 | 24.22±3.22; 5137 |
| Change in bicarbonate (mmol/L)b | 0.02±2.97; 12,772 | −0.16±3.12; 4864 |
| BUN (mg/dl)a | 56.21±18.53; 14,941 | 56.17±19.27; 5631 |
| Change in BUN (mg/dl)b | −0.21±15.50; 14,400 | −0.13±16.55; 5416 |
| URRa | 74.92±6.52; 14,273 | 75.05±6.61; 5348 |
| Change in URRb | 0.09±5.89; 13,548 | 0.07±6.08; 5054 |
| Sodium (mmol/L)a | 137.50±3.37; 13,139 | 137.08±3.52; 5046 |
| Change in sodium (mmol/L)b | −0.10±2.83; 29,324 | −0.25±3.10; 4772 |
| Potassium (mmol/L)a | 4.80±0.68; 16,051 | 4.78±0.70; 6217 |
| Change in potassium (mmol/L)b | 0.01±0.60; 15,499 | −0.01±0.63; 6003 |
| Phosphate (mg/dl)a | 5.55±1.74; 15,489 | 5.37±1.71; 5913 |
| Change in phosphate (mg/dl)b | 0.01±1.48; 14,918 | −0.03±1.46; 5692 |
| Chloride (meq/L)a | 98.66±4.14; 12,602 | 98.33±4.13, 4702 |
| Change in chloride (meq/L)b | −0.19±3.35; 11,708 | −0.24±3.50; 4450 |
| Calcium (mg/dl)a | 8.89±0.69; 15,420 | 8.78±0.73; 5878 |
| Change in calcium (mg/dl)b | 0.02±0.58; 14,882 | −0.07±0.60; 5659 |
| Corrected calcium (mg/dl)a | 9.06±0.66; 12,865 | 9.04±0.71; 4903 |
| Change in corrected calcium (mg/dl)b | 0.01±0.54; 12,148 | −0.03±0.59; 4608 |
| iPTH (pg/ml)a | 489.46±454.13; 10,090 | 497.22±490.12; 3801 |
| Change in iPTH (pg/ml)b | −21.39±280.41; 7245 | −21.84±296.17; 2734 |
| Ferritin (ng/ml)a | 1029.94±576.07; 8229 | 1197.32±900.22; 3138 |
| Change in ferritin (ng/ml)b | 52.90±505.99; 4400 | 142.00±739.89; 1589 |
| TSAT (%)a | 33.07±14.10; 13,051 | 31.29±14.42; 5008 |
| Change in TSAT (%)b | 0.17±15.33; 12,310 | −1.59±16.54; 4689 |
| Hgb (g/dl)a | 10.76±1.24; 29,324 | 10.61±1.26; 11,166 |
| Change in Hgb (g/dl)b | 0.05±1.07; 29,324 | 0.01±1.13; 11,166 |
| Platelet count (×109/L)a | 195.49±72.47; 11,378 | 192.35±77.10; 4293 |
| Change in platelet count (×109/L)b | −1.93±49.23; 10,595 | −7.82±55.06; 3963 |
| WBC count (×109/L)a | 6.93±2.36; 13,043 | 6.55±2.39; 5027 |
| Change in WBC count (×109/L)b | 0.03±1.76; 12,344 | −0.36±1.93; 4733 |
| % of neutrophilsa | 66.11±9.50; 17,215 | 66.59±9.53; 6941 |
| Change in % of neutrophilsb | 0.06±6.72; 14,931 | 0.47±7.37; 5997 |
| % of lymphocytesa | 20.22±7.98; 17,215 | 19.76±7.96; 6941 |
| Change in % of lymphocytesb | −0.04±4.99; 14,931 | −0.53±5.57; 5997 |
| % of monocytesa | 6.38±1.90; 17,215 | 6.69±2.14; 6941 |
| Change in % of monocytesb | 0.02±1.48; 14,931 | 0.37±1.82; 5997 |
| % of eosinophilsa | 4.29±2.88; 17,212 | 3.95±2.84; 6939 |
| Change in % of eosinophilsb | −0.10±2.03; 14,927 | −0.40±2.28; 5995 |
| % of basophilsa | 0.75±0.47; 17,206 | 0.73±0.45; 6934 |
| Change in % of basophilsb | 0.05±0.54; 14,917 | 0.03±0.52; 5988 |
All variables were included in the ML prediction model to classify the risk of an individual HD patient having a SARS-CoV-2 infection being identified in the following ≥3 d. HD, hemodialysis; Hgb, hemoglobin; WBC, white blood cell; TSAT, transferrin saturation; URR, urea reduction ratio; iPTH, intact parathyroid hormone; ML, machine learning; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
Mean values of laboratory variables 1–14 d before the prediction date (i.e., 3 d before suspicion of SARS-CoV-2 infection in standard clinical practice).
Mean values of the difference in laboratory variables 31–60 d to 1–14 d before the prediction date.