Table 1.
Baseline characteristics, laboratory and outcome data for all patients combined (n = 306) and by Ct value (viral load).
| All patients n = 306 |
Ct value (viral load) |
p Valuea | p Valueb | ||||
|---|---|---|---|---|---|---|---|
| ≤20 n = 42 |
21–25 n = 87 |
26–30 n = 94 |
>30 n = 83 |
||||
| Demographics | |||||||
| Age, years | 61 [41–74] | 73 [36–85] | 61 [41–71] | 63 [43–73] | 59 [40–73] | 0.146 | 0.031 |
| Female sex (%) | 174 (57) | 28 (67) | 43 (49) | 61 (65) | 42 (51) | 0.060 | 0.183 |
| White ethnicity (%) | 271 (89) | 37 (88) | 74 (85) | 82 (87) | 78 (94) | 0.304 | 1.000 |
| Current smoker (%) | 92 (30) | 9 (21) | 28 (32) | 30 (34) | 25 (30) | 0.608 | 0.209 |
| Influenza vaccinec | 171 (56) | 24 (57) | 43 (49) | 60 (67) | 44 (53) | 0.242 | 1.000 |
| Comorbidity | |||||||
| Cardiovascular (%) | 128 (43) | 22 (54) | 39 (45) | 39 (42) | 32 (40) | 0.486 | 0.180 |
| Respiratory (%) | 232 (77) | 30 (73) | 65 (76) | 76 (82) | 57 (70) | 0.357 | 0.701 |
| Renal (%) | 7 (2) | 1 (2) | 0 (0) | 3 (3) | 3 (4) | 0.382 | 1.000 |
| Liver (%) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) | NA | NA |
| Diabetes mellitus (%) | 35 (12) | 6 (15) | 9 (10) | 8 (8) | 12 (15) | 0.551 | 0.598 |
| Cancer (%) | 6 (2) | 1 (2) | 1 (1) | 3 (3) | 0 (0) | 0.385 | 0.522 |
| Clinical group | |||||||
| Asthma (%) | 95 (31) | 10 (24) | 33 (38) | 34 (36) | 18 (22) | 0.058 | 0.369 |
| IECOPD (%) | 108 (35) | 13 (31) | 37 (43) | 29 (31) | 29 (35) | 0.368 | 0.604 |
| CAP (%) | 56 (18) | 8 (19) | 5 (6) | 15 (16) | 28 (34) | <0.0001 | 0.833 |
| ILI/bronchitis (%) | 47 (15) | 11 (26) | 12 (14) | 16 (17) | 8 (10) | 0.100 | 0.062 |
| Virus type | |||||||
| Influenza (%) | 73 (24) | 13 (31) | 20 (23) | 20 (21) | 20 (24) | 0.671 | 0.247 |
| Rhino/enterovirus (%) | 149 (49) | 16 (38) | 42 (48) | 46 (49) | 45 (54) | 0.303 | 0.183 |
| Other virusesd (%) | 84 (27) | 13 (31) | 25 (29) | 28 (30) | 18 (22) | 0.578 | 0.580 |
| Clinical features | |||||||
| Duration of illness priore, days | 4 [2–7] | 4 [2–7] | 4 [2–7] | 4 [2–6.4] | 4 [2–7] | 0.879 | 0.643 |
| Antibiotics priore (%) | 73 (24) | 9 (21) | 21 (24) | 26 (28) | 17 (20) | 0.723 | 0.846 |
| Antibiotics during (%) | 243 (82) | 37 (88) | 67 (81) | 76 (82) | 63 (79) | 0.655 | 0.386 |
| IV Antibiotics during (%) | 88 (30) | 16 (38) | 26 (31) | 19 (20) | 27 (34) | 0.112 | 0.204 |
| Pulse rate, bpm | 98.5 [85–112] | 95 [84–111] | 100 [90–115] | 98 [84–114] | 96 [84–110] | 0.347 | 0.514 |
| Respiratory rate, bpm | 22 [20–26] | 23 [19–24] | 23 [20–26] | 22 [20–25] | 23 [20–26] | 0.567 | 0.988 |
| Systolic blood pressure, mmHg | 130 [118–145] | 134 [121–157] | 130 [115–145] | 134 [120–147] | 125 [115–140] | 0.165 | 0.361 |
| Temperature, °C | 37 [36.5–37.5] | 37 [36.6–37.5] | 37 [36.5–37.7] | 37 [36.5–37.4] | 37 [36.4–37.5] | 0.728 | 0.821 |
| O2 Saturations, % | 96 [93–98] | 96 [93–98] | 96 [94–98] | 96 [93–98] | 95 [92–97] | 0.437 | 0.801 |
| Laboratory | |||||||
| WCC ×109/L | 10.5 [7.8–13.8] | 9.9 [7.1–12.8] | 10.2 [7.7–13] | 10.8 [7.9–14] | 11.2 [8.3–14.5] | 0.133 | 0.134 |
| CRP, mg/L | 28 [13–71] | 31 [14–77] | 26 [10–56] | 27 [8–63] | 36 [14–127] | 0.205 | 0.523 |
| Ct value | 27 [23–31] | 18 [17–20] | 23 [22–24] | 28 [27–29] | 33 [32–34] | NA | NA |
| Pneumococcal detection (%) | 37 (12) | 5 (12) | 9 (10) | 10 (11) | 13 (16) | 0.691 | 1.000 |
| Any bacteria detected (%) | 57 (19) | 7 (17) | 12 (14) | 15 (16) | 23 (28) | 0.093 | 0.833 |
| Outcome | |||||||
| Length of stay, days | 2 [1–6] | 6 [2–10.3] | 2 [1–5] | 2 [1–4] | 2 [1–5] | 0.0002 | <0.0001 |
| ICU admission (%) | 1 (0) | 0 (0) | 0 (0) | 0 (0) | 1 (1) | 0.441 | 1.000 |
| Death (%) | 9 (3) | 1 (2) | 0 (0) | 6 (7) | 2 (2) | 0.083 | 1.000 |
Data are presented as number (%) and median [Inter-quartile range].
Abbreviations are: Ct, real-time PCR cycle threshold (a low Ct value represents a high viral load and vice versa); IECOPD, infective exacerbation of COPD; CAP, community acquired pneumonia; ILI, Influenza-like illness; IV, intravenous; WCC, white cell count; CRP, C reactive protein; ICU, intensive care unit; NA, not applicable.
p values highlighted in bold are statistically significant (i.e., p <0.05).
Across all Ct value groups (Kruskal–Wallis test).
Between high viral load group (Ct ≤ 20) and other groups combined (Chi squared test).
Receipt this influenza season.
Includes; Respiratory Syncytial Virus, parainfluenza 1–4, human metapneumovirus, coronavirus and adenovirus.
Prior to hospitalisation.