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, years53.5 (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 hospitalisation7 (23.3%)6 (40.0%)1 (6.7%)‡ 0.03
ICU admission4 (13.3%)4 (26.7%)0 (0%)‡ 0.03
Duration from illness onset to hospital admission, d6 (4, 9.7)6 (4.5, 10.5)6 (1.75, 7.5)0.55
Duration of viral shedding in respiratory tract, d17.5 (14, 23.7)18 (14, 22.5)17.5 (14.5, 26.25)0.98
Days of hospitalisation, d17 (14.2, 23.7)17 (15, 22)19.5 (13.75, 25.75)0.65
PFTs
FVC95.5 (89, 105)93 (84, 96)101.5 (94.7, 107.2)‡ 0.03
FEV195.5 (86.2, 107)91 (82.5, 97)103 (90.5, 112)‡ 0.02
PEF82 (71.2, 101)77 (71.5, 90)95.5 (75.2, 101)0.41
FEV1/FVC ratio80.25 (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
MVV88 (67.2, 103.7)75 (64, 95.5)96 (78.7, 109.2)0.08
DLCO88.5 (78.5, 95)86 (78, 92)94.5 (79.5, 99)0.07
DLCO/VA73 (67, 79.7)73 (67, 83.5)73 (68.2, 79.2)0.82
IVC83.5 (77.2, 92)82 (70.5, 86.5)88.5 (82.5, 93.5)‡ 0.05
TLC96 (91.2, 105.7)92 (84.5, 98.5)98 (96, 106)‡ 0.05
RV120 (106.2, 130.7)123 (102.5, 130.5)120 (106.7, 129)0.90
RV/TLC124.5 (111.2, 142.7)132 (113.5, 150)120.5 (110.7, 133.5)0.23
Exercise capacity
Pre-6WMT heart rate84 (75.7, 91)85 (81.5, 96)82 (74.5, 86.5)0.15
Pre-6WMT systolic blood pressure130.5 (116.2, 142.7)133 (114, 156.5)123 (115.5, 136.2)0.40
Pre-6WMT diastolic blood pressure77.5 (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, m600 (540, 640)620 (575, 640)560 (515, 654)0.77
Post-6WMT heart rate103.5 (98.2, 113.7)106 (100, 115)101.5 (97.5, 106.75)0.20
Post-6WMT systolic blood pressure129 (122, 142.5)140 (124, 158.5)127.5 (121.2, 132.2)0.06
Post-6WMT diastolic blood pressure80 (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.