Comparison of the Clinical Characteristics and Severity of Influenza and Non-influenza Respiratory Virus-Related Pneumonia in China: A Multicenter, Real-World Study

Figures & data

Figure 1 Screening algorithm of patients hospitalized with RVs-p.

Notes: A total of 4150 patients with nucleic acids positive for respiratory viruses were screened, and 1420 eligible patients with respiratory viruses-related pneumonia were included in the study.

Table 1 Comparison of Clinical and Radiologic Features Between Patients with Flu-p and NIRVs-p

Variables	Flu-p (n = 1079)	NIRVs-p (n = 341)	p value
Age (median, IQR, years)*	61.0 (49.0–78.0)	60.0 (42.0–70.0)	0.003
Male (n, %)	584 (54.1)	185 (54.3)	0.967
Days from disease onset to admission (median, IQR)	3.0 (2.0–4.0)	4.0 (3.0–6.0)	0.480
Comorbidities (n, %)
Cardiovascular disease	259 (24.0)	86 (25.2)	0.648
Diabetes mellitus	127 (11.8)	38 (11.1)	0.753
Cerebrovascular disease	97 (9.0)	42 (12.3)	0.072
COPD*	91 (8.4)	63 (18.5)	<0.001
Asthma	33 (3.0)	12 (3.5)	0.672
CKD	30 (2.8)	15 (4.4)	0.137
Solid malignant tumor*	24 (2.2)	22 (6.5)	<0.001
Obesity (n, %)*	76 (7.0)	63 (18.5)	<0.001
Pregnancy (n, %)	8 (0.7)	0 (0.0)	0.238
Smoking history (n, %)*	313 (29.0)	114 (33.4)	<0.001
Baseline clinical and radiologic features (n, %)
Fever ≥38°C*	814 (75.4)	229 (67.2)	0.003
Nosal congestion	194 (18.0)	62 (18.2)	0.933
Rhinorrhea	234 (21.7)	61 (17.9)	0.132
Sore throat	202 (18.7)	60 (17.6)	0.640
Myalgia*	376 (34.8)	73 (21.4)	<0.001
Diarrhea	8 (0.7)	5 (1.5)	0.369
Cough	1060 (98.2)	332 (97.4)	0.209
Sputum production*	854 (79.1)	127 (37.2)	<0.001
Chest pain	182 (16.9)	56 (16.4)	0.848
Dyspnea*	690 (63.9)	187 (54.8)	0.003
Confusion	150 (13.9)	42 (12.3)	0.456
Respiratory rates ≥30 beats/min	146 (13.5)	47 (13.8)	0.906
SBP <90mmHg	15 (1.4)	4 (1.2)	0.973
Rhonchi	187 (17.3)	67 (19.6)	0.330
Moist rale	31 (2.9)	6 (1.8)	0.261
Leukocytes >10×10^9/L	283 (26.2)	73 (21.4)	0.076
Lymphocytes <0.8×10^9/L*	480/1063 (45.2)	25 (7.3)	<0.001
HB <100 g/L	240 (22.2)	64 (18.8)	0.173
ALB <35 g/L*	187/1025 (18.2)	132 (38.7)	<0.001
BUN > 7 mmol/L*	446/1071 (41.6)	113 (33.1)	0.005
PO2/FiO2 <250 mmHg	310/1025 (30.2)	89 (26.1)	0.145
Radiology (n, %)
Multilobar infiltrates	794 (73.6)	234 (68.6)	0.087
Pleural effusion	339 (31.4)	97 (28.4)	0.300
CURB-65 score			<0.001
0–1	760/1071 (71.0)	243 (71.3)
2	180/1071 (16.8)	74 (21.7)
3–5	131/1071 (12.2)	24 (7.0)
PSI risk class			<0.001
I–II	436/850 (51.3)	188 (55.1)
III	139/850 (16.4)	84 (24.6)
IV–V	275/850 (32.3)	69 (20.2)
Coinfections (n, %)	367 (34.0)	104 (30.5)	0.230

Notes: *The values were entered into the multivariate logistic regression model; the bolded values are p-values <0.05, which represented significant differences between Flu-p patients and NIRVs-p patients.

Abbreviations: Flu-p, influenza-related pneumonia; NIRVS-p, non-influenza respiratory viruses-related pneumonia; IQR, interquartile range; COPD, chronic obstructive pulmonary disease; CKD, chronic kidney disease; SBP, systolic blood pressure; HB, haemoglobin; ALB, albumin; BUN, blood urea nitrogen; PO₂/FiO₂, arterial pressure of oxygen/fraction of inspiration oxygen; CURB-65, mental confusion, urea, respiratory rate, blood pressure, age ≥65 years; PSI, pneumonia severity index.

Table 2 Comparison of Clinical Management and Outcomes Between Patients with Flu-p and NIRVs-p

Variables	Flu-p (n = 1079)	NIRVs-p (n = 341)	p value
Systemic corticosteroid use (n, %)	262 (24.3)	43 (12.6)	<0.001
Antiviral treatment (n, %)	1079 (100.0)	0 (0.0)	<0.001
Non-invasive ventilation (n, %)	279 (25.9)	53 (15.5)	<0.001
Invasive ventilation (n, %)	193 (17.9)	28 (8.2)	<0.001
Vasopressor use (n, %)	40 (3.7)	8 (2.3)	0.225
Complications (n, %)
Respiratory failure	249 (23.1)	47 (13.8)	<0.001
Heart failure	265 (24.6)	49 (14.4)	<0.001
Septic shock	89 (8.2)	11 (3.2)	0.002
Acute renal failure	66 (6.1)	9 (2.6)	0.012
ICU admission (n, %)	242 (22.4)	31 (9.1)	<0.001
Length of stay in hospital (median, IQR, days)	10.0 (8.0–14.0)	11.0 (8.0–14.0)	0.007
30-day mortality (n, %)	208 (19.3)	32 (9.4)	<0.001

Notes: The bolded values are p-values <0.05, which represented significant differences between Flu-p patients and NIRVs-p patients.

Abbreviation: ICU, intensive care unit.

Figure 2 Forest plot of predictors for Flu-p.

Notes: Malgia and lymphocytes <0.8×10⁹/L were positively associated with Flu-p; while COPD, solid malignant tumor and blood albumin <35 g/L were positively associated with NIRVs-p.

Table 3 Impact of Viruses Types on Clinical Outcomes of Patients with RVs-p

Clinical Outcomes	Virus Type	Cases (n, %)	Univariate Logistic Analysis		Multivariate Logistic Analysis
			OR (95% CI)	p-value	*aOR (95% CI)	p-value
Invasive ventilation	Flu A	158 (22.8)	Ref		Ref
	Flu B	35 (9.1)	0.338 (0.229–0.499)	<0.001	0.200 (0.127–0.315)	<0.001
	RSV	14 (11.0)	0.420 (0.234–0.752)	0.003	0.370 (0.198–0.691)	0.002
	hRV	6 (9.1)	0.339 (0.144–0.798)	0.013	0.299 (0.124–0.717)	0.007
	hPIV	1 (2.4)	0.083 (0.011–0.605)	0.014	0.074 (0.010–0.557)	0.011
	hMPV	6 (10.9)	0.415 (0.174–0.986)	0.046	0.341 (0.139–0.840)	0.019
	hAdV	1 (2.0)	0.068 (0.009–0.494)	0.008	0.087 (0.012–0.641)	0.017
	NIRVs	28 (8.2)	0.303 (0.198–0.464)	<0.001	0.273 (0.175–0.425)	<0.001
Admittance to ICU	Flu A	176 (25.4)	Ref		Ref
	Flu B	66 (17.1)	0.606 (0.442–0.831)	0.002	0.546 (0.363–0.820)	0.004
	RSV	14 (11.0)	0.364 (0.204–0.651)	0.001	0.513 (0.275–0.957)	0.036
	hRV	7 (10.6)	0.349 (0.156–0.777)	0.010	0.259 (0.112–0.599)	0.002
	hPIV	1 (2.4)	0.072 (0.010–0.525)	0.009	0.073 (0.010–0.540)	0.010
	hMPV	6 (10.9)	0.360 (0.151–0.854)	0.020	0.477 (0.190–1.196)	0.114
	hAdV	3 (5.9)	0.184 (0.056–0.597)	0.015	0.206 (0.062–0.685)	0.010
	NIRVs	31 (9.1)	0.304 (0.203–0.455)	<0.001	0.325 (0.212–0.425)	<0.001
30-day mortality	Flu A	136 (19.6)	Ref		Ref
	Flu B	72 (18.7)	0.939 (0.684–1.290)	0.698	0.419 (0.272–0.646)	<0.001
	RSV	18 (14.2)	0.676 (0.397–1.152)	0.150	0.422 (0.219–0.813)	0.010
	hRV	5 (7.6)	0.336 (0.132–0.852)	0.022	0.167 (0.061–0.457)	<0.001
	hPIV	1 (2.4)	0.100 (0.014–0.733)	0.023	0.109 (0.014–0.820)	0.031
	hMPV	4 (7.3)	0.321 (0.114–0.904)	0.031	0.192 (0.061–0.599)	0.004
	hAdV	4 (7.8)	0.349 (0.123–0.984)	0.047	0.261 (0.061–0.835)	0.024
	NIRVs	32 (9.4)	0.424 (0.282–0.639)	<0.001	0.260 (0.158–0.467)	<0.001

Notes: *Adjusted for age, sex, comorbidities, obesity, smoking history, pregnancy, antiviral treatment, systemic corticosteroids use and coinfections.

Abbreviations: OR, odd ratio; CI, confidence interval.

Table 4 Risk Factors for 30-Day Mortality in Patients with RVs-p

Variables	OR (95% CI)	p value
Age	1.021 (1.009–1.033)	0.001
FluA-p	3.556 (2.274–5.559)	<0.001
COPD	1.766 (1.067–2.925)	0.027
CKD	3.899 (1.817–8.363)	<0.001
Smoking history	6.488 (4.043–10.412)	<0.001
Confusion	2.914 (1.746–4.862)	<0.001
Lymphocytes <0.8×10^9/L	4.471 (2.820–7.091)	<0.001
BUN >7 mmol/L	5.398 (3.430–8.495)	<0.001
PO2/FiO2 <250 mmHg	1.504 (1.041–2.172)	0.030