Analysis of clinical characteristics and risk factors between elderly patients with severe and nonsevere Omicron variant infection

Table 1 Comparison of clinical data between the severe and non-severe groups of elderly patients with coronavirus disease 2019

Variables	Total (n = 328)	Non-severe (n = 246)	Severe (n = 82)	P value
Age (yr)	77.0 (68.0, 86.0)	74.0 (64.0, 84.0)	84.0 (75.0, 89.0)	< 0.001
Male sex	155 (47.4)	108 (43.9)	47 (57.3)	0.037
Vaccinations (times)	0 (0, 0)	0 (0, 2)	0 (0, 0)	< 0.001
Comorbidities
Chronic respiratory disease	37 (11.2)	20 (7.8)	17 (20.7)	0.001
Hypertension	185 (56.4)	135 (54.8)	50 (61.0)	0.332
Diabetes mellitus	65 (19.9)	44 (17.8)	21 (25.6)	0.129
Coronary heart disease	56 (17.0)	40 (16.1)	16 (19.5)	0.478
Cerebral infarction	64 (19.6)	34 (13.5)	30 (36.6)	< 0.001
Chronic kidney disease	16 (4.8)	7 (2.6)	9 (11.0)	0.002
Immune system disease	6 (1.9)	5 (2.2)	1 (1.2)	0.589
Neoplastic disease	31 (9.6)	23 (9.6)	8 (9.8)	0.96
Neurodegenerative diseases	23 (7.1)	8 (3.0)	15 (18.3)	< 0.001
Other comorbidities	99 (30.1)	69 (27.8)	30 (36.6)	0.138
Symptoms
Fever	61 (18.6)	33 (13.0)	28 (34.1)	< 0.001
Pharyngodynia	58 (17.6)	41 (16.5)	17 (20.7)	0.39
Cough	149 (45.5)	98 (39.6)	51 (62.2)	< 0.001
Nasal stuffiness	31 (9.6)	18 (7.4)	13 (15.8)	0.026
Diarrhea	3 (1.0)	1 (0.4)	2 (2.4)	0.11
Other symptoms	21 (6.4)	9 (3.5)	12 (14.6)	< 0.001
Laboratory data
D-dimers (mg/ml)	0.66 (0.30, 1.85)	0.42 (0.21, 0.82)	3.19 (1.33, 7.32)	< 0.001
eGFR (ml/min/1.73 m2)	76.63 ± 23.62	78.59 ± 20.82	71.09 ± 29.47	0.039
TNF-α (pg/ml)	9.78 (7.47, 12.60)	8.85 (7.12, 11.10)	12.37 (10.90, 18.80)	< 0.001
IL-10 (pg/ml)	5.00 (5.00, 5.82)	5.00 (5.00, 5.00)	6.47 (5.24, 8.99)	< 0.001
IL-1β (pg/ml)	5.00 (5.00, 5.55)	5.00 (5.00, 5.00)	5.55 (5.00, 7.17)	< 0.001
PCT (ng/ml)	1.58 ± 6.76	0.14 ± 0.57	5.66 ± 12.31	< 0.001
CRP (mg/L)	23.41 ± 38.25	9.83 ± 21.20	61.96 ± 48.30	< 0.001
WBC (109/L)	6.82 ± 3.29	5.92 ± 1.93	9.36 ± 4.72	< 0.001
Neutrophil percentage	69.80 ± 14.30	64.44 ± 11.38	85.02 ± 10.22	< 0.001
Lactic acid (mmol/L)	1.80 (1.37, 2.30)	1.64 (1.25, 2.00)	2.47 (1.81, 3.20)	< 0.001
SIRI	3.45 ± 5.08	1.71 ± 1.93	8.36 ± 7.48	< 0.001
NLR	5.27 ± 5.58	3.19 ± 3.05	11.17 ± 6.79	< 0.001
Oxygen saturation	96.13 (93.00, 97.13)	96.60 (95.98, 97.73)	91.00 (89.00, 92.90)	< 0.001
Treatment
Respiratory support	108 (33.01)	29 (10.44)	79 (96.34)	< 0.001
Paxlovid	196 (59.62)	148 (60.00)	48 (58.54)	0.817
Glucocorticoids	78 (23.72)	24 (8.70)	54 (65.85)	< 0.001
Anticoagulation (low molecular weight heparin or regular heparin)	98 (29.81)	42 (16.09)	56 (68.29)	< 0.001
Lianhua Qingwen Granule	212 (64.74)	169 (69.13)	43 (52.44)	0.007
Antibiotics	113 (34.30)	46 (17.39)	67 (81.71)	< 0.001
Length of hospital stays (d)	8 (5, 11)	7 (5, 10)	8 (5, 14)	0.011
Viral shedding time (d)	9.25 ± 5.84	8.65 ± 4.87	10.95 ± 7.74	0.014
Death	15 (4.57)	0 (0.00)	15 (18.29)	< 0.001

Data are expressed as median (interquartile range), mean ± SD deviation, or number (percentage). eGFR: Estimated glomerular filtration rate; TNF: Tumor necrosis factor; IL: Interleukin; PCT: Procalcitonin; CRP: C-reactive protein; WBC: White blood cell; SIRI: Systemic inflammatory response index; NLR: Neutrophil to lymphocyte ratio.

Table 2 Univariate and multivariate analysis of the development of severe infection in elderly patients with coronavirus disease 2019

Variables	Univariate analysis OR (95%CI)	P value	Multivariate analysis OR (95%CI)	P value
Age	1.084 (0.978, 1.202)	0.126	-	-
Sex	0.575 (0.1, 3.322)	0.536	-	-
Vaccinations	0.636 (0.039, 10.385)	0.751	-	-
Chronic respiratory disease	0.559 (0.025, 12.453)	0.713	-	-
Diabetes mellitus	7.76 (0.446, 134.92)	0.16	-	-
Hypertension	3.267 (0.365, 29.275)	0.29	-	-
Coronary heart disease	0.142 (0.01, 1.926)	0.142	-	-
Cerebral infarction	7.757 (0.704, 85.443)	0.094	4.26 (1.012, 17.937)	0.048
Chronic kidney disease	0.057 (0.001, 4.578)	0.2	-	-
Neurodegenerative diseases	19.385 (0.149, 2527.003)	0.233	-	-
Neoplastic disease	0.527 (0.022, 12.846)	0.695	-	-
Immune system disease	0 (0, 203.169)	0.213	-	-
WBC	1.096 (0.669, 1.794)	0.716	-	-
Neutrophil percentage	1.125 (0.95, 1.331)	0.172	-	-
eGFR	1.044 (0.966, 1.128)	0.281	-	-
NLR	1.017 (0.636, 1.626)	0.943	-	-
SIRI	1.003 (0.534, 1.883)	0.993	-	-
CRP	1.023 (0.984, 1.063)	0.251	-	-
PCT	1.552 (0.67, 3.598)	0.305	-	-
Oxygen saturation	0.513 (0.369, 0.714)	0.000	0.573 (0.451, 0.728)	0.000
Lactic acid	0.768 (0.269, 2.194)	0.622	-	-
D-dimers	1.156 (0.754, 1.772)	0.507	1.394 (1, 1.944)	0.05
Viral shedding time	1.066 (0.892, 1.274)	0.484	-	-
Lianhua Qingwen Granule	0.486 (0.055, 4.302)	0.517	-	-
Paxlovid	2.505 (0.19, 33.049)	0.485	-	-

Bold letters represent significant predictors of the development of severe infection in elderly patients with coronavirus disease 2019. OR: Odds ratio; CI: Confidence interval; eGFR: Estimated glomerular filtration rate; NLR: Neutrophil to lymphocyte ratio; SIRI: Systemic inflammatory response index; CRP: C-reactive protein; PCT: Procalcitonin; WBC: White blood cell.