Table 1.
Comparison of clinical characteristics between patients with high or low microbial richness in the recovery phase
| All (n=30) | Low (n=15) | High (n=15) | P value | |
| Age, years | 53.5 (39.75, 59) | 53 (40, 57.5) | 53 (37, 59.75) | 0.72 |
| Male, n (%) | 19 (63.3%) | 10 (66.7%) | 9 (60%) | 0.70 |
| BMI of acute phase, kg/m2 | 24.2 (21.6, 25.2) | 24.9 (22.3, 25.8) | 23.8 (21.3, 25.0) | 0.36 |
| BMI of postconvalescence, kg/m2 | 24.1 (21.1, 26.6) | 24.7 (22.2, 27.2) | 23.1 (21.0, 25.3) | 0.41 |
| Severe illness during hospitalisation, n (%) | 10 (33.3%) | 7 (46.7%) | 3 (20.0%) | 0.12 |
| White cell count, ×109/L * | 5.7 (4.1, 8.9) | 5.7 (4.3, 9.9) | 6.5 (4.1, 8.0) | 0.79 |
| Haemoglobin, g/L * | 138 (128, 149) | 146 (128, 152) | 137 (129, 141) | 0.28 |
| Platelet count, ×109/L * | 187 (158, 231) | 188 (168, 238) | 182 (139, 225) | 0.53 |
| Neutrophil count, ×109/L * | 3.9 (2.6, 7.1) | 4.3 (2.9, 8.7) | 3.9 (2.5, 6.7) | 0.75 |
| Lymphocyte count, ×109/L * | 0.8 (0.6, 1.2) | 0.7 (0.5, 1.2) | 0.9 (0.6, 1.1) | 0.59 |
| D-dimer, mg/L * | 236 (170, 467) | 407 (175, 913) | 199 (170, 320) | 0.08 |
| CRP, mg/L * | 10.8 (5.9, 21.5) | 15.4 (10.5, 45.7) | 7.5 (2.2, 11.4)‡ | 0.01 |
| HFNC during hospitalisation | 7 (23.3%) | 6 (40.0%) | 1 (6.7%)‡ | 0.03 |
| ICU admission | 4 (13.3%) | 4 (26.7%) | 0 (0%)‡ | 0.03 |
| Duration from illness onset to hospital admission, d | 6 (4, 9.7) | 6 (4.5, 10.5) | 6 (1.75, 7.5) | 0.55 |
| Duration of viral shedding in respiratory tract, d | 17.5 (14, 23.7) | 18 (14, 22.5) | 17.5 (14.5, 26.25) | 0.98 |
| Days of hospitalisation, d | 17 (14.2, 23.7) | 17 (15, 22) | 19.5 (13.75, 25.75) | 0.65 |
| PFTs† | ||||
| FVC | 95.5 (89, 105) | 93 (84, 96) | 101.5 (94.7, 107.2)‡ | 0.03 |
| FEV1 | 95.5 (86.2, 107) | 91 (82.5, 97) | 103 (90.5, 112)‡ | 0.02 |
| PEF | 82 (71.2, 101) | 77 (71.5, 90) | 95.5 (75.2, 101) | 0.41 |
| FEV1/FVC ratio | 80.25 (74.4, 88.0) | 80.7 (76.4, 87.9) | 80.25 (73.8, 88.0) | 0.84 |
| FEF25%–75% | 87.5 (65, 120.2) | 87 (69.5, 101) | 87 (65, 135) | 0.63 |
| MEF 75% | 86 (72.7, 111) | 80 (74.5, 89.5) | 104 (77, 111.7) | 0.55 |
| MEF 50% | 80.5 (70, 102.7) | 81 (70, 91) | 79.5 (71.7, 118.7) | 0.88 |
| MEF 25% | 74.5 (57.2, 114) | 74 (50, 100) | 73 (58.7, 127.2) | 0.48 |
| MVV | 88 (67.2, 103.7) | 75 (64, 95.5) | 96 (78.7, 109.2) | 0.08 |
| DLCO | 88.5 (78.5, 95) | 86 (78, 92) | 94.5 (79.5, 99) | 0.07 |
| DLCO/VA | 73 (67, 79.7) | 73 (67, 83.5) | 73 (68.2, 79.2) | 0.82 |
| IVC | 83.5 (77.2, 92) | 82 (70.5, 86.5) | 88.5 (82.5, 93.5)‡ | 0.05 |
| TLC | 96 (91.2, 105.7) | 92 (84.5, 98.5) | 98 (96, 106)‡ | 0.05 |
| RV | 120 (106.2, 130.7) | 123 (102.5, 130.5) | 120 (106.7, 129) | 0.90 |
| RV/TLC | 124.5 (111.2, 142.7) | 132 (113.5, 150) | 120.5 (110.7, 133.5) | 0.23 |
| Exercise capacity | ||||
| Pre-6WMT heart rate | 84 (75.7, 91) | 85 (81.5, 96) | 82 (74.5, 86.5) | 0.15 |
| Pre-6WMT systolic blood pressure | 130.5 (116.2, 142.7) | 133 (114, 156.5) | 123 (115.5, 136.2) | 0.40 |
| Pre-6WMT diastolic blood pressure | 77.5 (69, 90.7) | 71 (66, 99) | 77.5 (70.5, 86.2) | 0.85 |
| Pre-6WMT O2 saturation, % | 98 (97, 99) | 98 (98, 99) | 98 (97, 99) | 0.88 |
| 6WMT distance, m | 600 (540, 640) | 620 (575, 640) | 560 (515, 654) | 0.77 |
| Post-6WMT heart rate | 103.5 (98.2, 113.7) | 106 (100, 115) | 101.5 (97.5, 106.75) | 0.20 |
| Post-6WMT systolic blood pressure | 129 (122, 142.5) | 140 (124, 158.5) | 127.5 (121.2, 132.2) | 0.06 |
| Post-6WMT diastolic blood pressure | 80 (70.7, 86) | 81 (69, 92.5) | 78.5 (73.7, 84) | 0.71 |
| Post-6WMT O2 saturation, % | 98 (97, 98) | 98 (97, 98) | 98 (97, 98) | 0.71 |
The quantitative data are shown as median data and IQR data in brackets.
The occurrence data are shown as no. (%). Values indicate no. of positive results/total no. of patients with available assay results.
Between-group comparisons of continuous variable in patients with low and high richness were tested by Kruskal-Wallis test. For categorical variable, χ² test test was used for comparison between groups.
Statistically significance with a p value ≤0.05 was marked as bold.
*The results of laboratory test in the acute phase were compared, usually the first day after hospital admission.
†Pulmonary function tests were expressed as per cent of the predicted value.
‡ A p value ≤0.05 was denoted as statistically significant.
MEF 25%, mean expiratory flow at 25%; MEF 50%, mean expiratory flow at 50%; MEF 75%, mean expiratory flow at 75%; BMI, body mass index; CRP, C reactive protein; DLCO, diffusing capacity of the lung for carbon monoxide; DLCO/VA, diffusing capacity divided by the alveolar volume; FEF25%–75%, forced expiratory flow at 25%–75%; FEV1, forced expiratory volume in the first 1 s of expiration; FVC, forced vital capacity; HFNC, high flow nasal catheter oxygen therapy; ICU, intensive care unit; IVC, inspiratory vital capacity; MVV, maximal voluntary ventilation; PEF, peak expiratory flow; PFTs, pulmonary function tests; RV, residual volume; RV/TLC, residual volume divided by the total lung capacity; TLC, total lung capacity; 6WMT, 6 min walk tests.