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. 2021 Sep 28;53(3):646–662. doi: 10.1007/s11239-021-02575-4

Table 4.

Comparisons of clot waveform analysis results between mildly ill Covid-19 patients and severely ill COVID-19 patients

Mildly ill COVID-19 patientsb (n = 8) Severely ill COVID-19 Patients (n = 10) p-value
Median (IQR) Median (IQR)
Delta change (aPTT) (%) (25.21–63.09)
 Baseline 55.2 (43.3, 62.4) 78.8 (69.8, 85.2) 0.001
 Day 3 55.1 (50.4, 60.6) 65.8 (58.8, 85.6) 0.06
 Day 6 61.7 (59.5, 64.6) 67.9 (56.9, 73.6) 0.63
 Day 9 62.2 (62.2, 62.2)a 66.4 (62.7, 71.2) 0.57
 Day 12 62.1 (62.1, 62.1)a 62.6 (59.2, 72.0) 0.99
 Day 15 56.9 (56.9, 56.9)a 60.2 (54.2, 72.2) 0.80
Min 1 (aPTT) (%/s) (2.86–6.78)
 Baseline 5.7 (4.9, 6.1) 7.8 (6.7, 8.3) 0.001
 Day 3 5.9 (5.2, 6.2) 6.8 (5.9, 8.1) 0.08
 Day 6 6.5 (5.9, 6.6) 7.0 (6.5, 7.7) 0.19
 Day 9 6.1 (6.1, 6.1)a 7.2 (4.7, 7.5) 0.99
 Day 12 6.1 (6.1, 6.1)a 7.2 (6.5, 7.8) 0.29
 Day 15 4.4 (4.4, 4.4)a 6.7 (6.0, 7.9) 0.40
Min 2 (aPTT) (%/s2) (0.46–1.10)
 Baseline 0.9 (0.8, 1.0) 1.2 (0.9, 1.3) 0.07
 Day 3 0.9 (0.9, 1.0) 1.1 (1.0, 1.5) 0.02
 Day 6 1.0 (0.9, 1.1) 1.1 (1.1, 1.2) 0.08
 Day 9 1.0 (1.0, 1.0)a 1.3 (1.0, 1.8) 0.25
 Day 12 0.9 (0.9, 0.9)a 1.2 (1.0, 1.3) 0.29
 Day 15 2.3 (2.3, 2.3)a 1.1 (1.0, 2.8) 0.80
Max2 (aPTT) (%/s2) (0.37–0.93)
 Baseline 0.7 (0.7, 0.8) 1.0 (0.7, 1.0) 0.04
 Day 3 0.8 (0.7, 0.8) 0.9 (0.8, 1.2) 0.11
 Day 6 0.9 (0.7, 0.9) 0.9 (0.9, 1.0) 0.19
 Day 9 0.7 (0.7, 0.7)a 1.1 (0.8, 1.4) 0.25
 Day 12 0.7 (0.7, 0.7)a 1.0 (0.9, 1.1) 0.29
 Day 15 1.7 (1.7, 1.7)a 0.9 (0.8, 2.3) 0.80
Delta change (PT) (%) (6.52–17.28)
 Baseline 14.9 (11.2, 16.7) 22.4 (19.4, 29.5) 0.004
 Day 3 14.8 (13.2, 17.0) 16.7 (14.2, 27.6) 0.28
 Day 6 16.8 (16.2, 19.4) 18.3 (15.2, 19.5) 0.92
 Day 9 17.4 (17.4, 17.4)a 16.3 (14.9, 20.7) 0.86
 Day 12 16.8 (16.8, 16.8)a 15.8 (14.6, 20.8) 0.86
 Day 15 14.2 (14.2, 14.2)a 15.2 (13.0, 21.8) 0.80
Min 1 (PT) (%/s) (1.95–5.67)
 Baseline 5.3 (4.1, 5.4) 7.1 (6.3, 9.0) 0.02
 Day 3 4.8 (4.3, 5.4) 5.0 (4.5, 8.5) 0.49
 Day 6 5.4 (5.1, 6.4) 5.5 (4.7, 5.9) 0.78
 Day 9 5.1 (5.1, 5.1)a 6.6 (4.8, 7.9) 0.75
 Day 12 5.1 (5.1, 5.1)a 5.1 (4.6, 6.7) 0.99
 Day 15 5.8 (5.8, 5.8)a 5.0 (4.2, 7.3) 0.80
Min 2 (PT) (%/s2) (0.97–2.93)
 Baseline 2.7 (2.1, 2.7) 3.6 (3.2, 4.5) 0.02
 Day 3 2.5 (2.2, 2.8) 2.5 (2.3, 4.4) 0.57
 Day 6 2.8 (2.5, 3.3) 2.8 (2.4, 3.0) 0.78
 Day 9 2.6 (2.6, 2.6)a 2.4 (1.1, 4.0) 0.99
 Day 12 2.5 (2.5, 2.5)a 2.7 (2.4, 3.4) 0.99
 Day 15 0.9 (0.9, 0.9)a 2.1 (1.7, 2.6) 0.40
Max 2 (PT) (%/s2) (0.75–2.35)
 Baseline 2.2 (1.7, 2.2) 2.9 (2.5, 3.5) 0.02
 Day 3 2.0 (1.8, 2.2) 1.9 (1.8, 3.3) 0.66
 Day 6 2.2 (1.9, 2.6) 2.2 (1.8, 2.3) 0.63
 Day 9 1.9 (1.9, 1.9)a 1.9 (0.9, 3.2) 0.99
 Day 12 1.9 (1.9, 1.9)a 2.1 (1.9, 2.7) 0.86
 Day 15 0.7 (0.7, 0.7)a 1.7 (1.3, 2.1) 0.40

Reference intervals for clot waveform parameters were established locally based on 124 healthy controls in accordance with the Clinical and Laboratory Standards Institute guidelines

aResults for 1 patient only, 9 others were discharged to community care facilities

b2 COVID-19 patients progressed from mildly ill to a moderately ill state, hence their CWA parameters were excluded from the analysis