Risk Factors for Mortality in 244 Older Adults With COVID-19 in Wuhan, China

A Retrospective Study

Haiying Sun, MD; Ruoqi Ning, MD; Yu Tao, MD; Chong Yu, MD; Xiaoyan Deng, MD; Caili Zhao, MM; Silu Meng, MM; Fangxu Tang, MD; Dong Xu, MD, PhD

Disclosures

J Am Geriatr Soc. 2020;68(6):E19-E23.

Abstract and Introduction

Abstract

Background/Objectives: Previous studies have reported that older patients may experience worse outcome(s) after infection with severe acute respiratory syndrome coronavirus-2 than younger individuals. This study aimed to identify potential risk factors for mortality in older patients with coronavirus disease 2019 (COVID-19) on admission, which may help identify those with poor prognosis at an early stage.

Design: Retrospective case-control.

Setting: Fever ward of Sino-French New City Branch of Tongji Hospital, Wuhan, China.

Participants: Patients aged 60 years or older with COVID-19 (n = 244) were included, of whom 123 were discharged and 121 died in hospital.

Measurements: Data retrieved from electronic medical records regarding symptoms, signs, and laboratory findings on admission, and final outcomes of all older patients with COVID-19, were retrospectively reviewed. Univariate and multivariate logistic regression analyses were used to explore risk factors for death.

Results: Univariate analysis revealed that several clinical characteristics and laboratory variables were significantly different (ie, P < .05) between discharged and deceased patients. Multivariable logistic regression analysis revealed that lymphocyte (LYM) count (odds ratio [OR] = 0.009; 95% confidence interval [CI] = 0.001–0.138; P = .001) and older age (OR = 1.122; 95% CI = 1.007–1.249; P = .037) were independently associated with hospital mortality. White blood cell count was also an important risk factor (P = .052). The area under the receiver operating characteristic curve in the logistic regression model was 0.913. Risk factors for in-hospital death were similar between older men and women.

Conclusion: Older age and lower LYM count on admission were associated with death in hospitalized COVID-19 patients. Stringent monitoring and early intervention are needed to reduce mortality in these patients. J Am Geriatr Soc 68:E19–E23, 2020.

Introduction

In December 2019, a cluster of cases of novel virus-related pneumonia occurred in Wuhan, China,^[1] and the number of infected persons has increased rapidly due to the high transmissibility and infectivity of the causative virus.^[2] The virus has been isolated and identified as a novel enveloped RNA beta-coronavirus (termed severe acute respiratory syndrome coronavirus-2 [SARS CoV-2]) using epidemiological, clinical, laboratory, and genetic methods.^[3] The World Health Organization has named this novel pneumonia as coronavirus disease 2019 (COVID-19) and declared it a global pandemic.^[4]

The city of Wuhan—the epidemic source of COVID-19—medical institutions and clinicians have been facing unprecedented challenges due to the rapid spread of the COVID-19 and increase in the number of patients. As of March 5, 2020, a total of 49,797 cases were confirmed in Wuhan, of which 2,328 died of COVID-19.^[5] The Sino-French New City Branch of Tongji Hospital was designated by the Chinese government as a specified hospital for treating severely and critically ill patients with COVID-19.

Older patients with COVID-19 have been reported to exhibit relatively higher mortality and severity of illness than younger patients.^[6,7] However, to the best of our knowledge, no previous study has reported definitive outcomes in older patients. Accordingly, this retrospective, single-center study aimed to identify early-stage risk factors associated with death, and to compare the clinical characteristics on admission of in-hospital deceased and discharged older patients with COVID-19.

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Next Section

Abstract and Introduction
Methods
Results
Discussion
References

Table 1. Demographic Information, Clinical Characteristics, and Laboratory Findings on Admission
Characteristic	Discharged (n = 123)^a	Deceased (n = 121)^a	P Value
Demographics
Sex			<.001
Male	51 (41.5)	82 (67.8)
Female	72 (58.5)	39 (32.2)
Age, y	67 (64–72)	72 (66–78)	<.001
Symptoms
Fever (≥37.3°C)	104 (84.6)	107 (88.4)	.376
Highest temperature (°C)	38.3 (37.8–39.0)	38.5 (38.0–39.0)	.560
Respiratory symptoms	105 (85.4)	111 (91.7)	.119
Cough	91 (74.0)	88 (72.7)	.824
Gastrointestinal symptoms	41 (33.3)	40 (33.1)	.964
Diarrhea	36 (29.3)	36 (29.8)	.934
Abdominal pain	5 (4.1)	5 (4.1)	1.000
Vital signs
SpO₂, %	97 (95–98)	90 (80–96)	<.001
Pulse heart rate, beats/min	86 (80–98)	94 (81–110)	<.001
Respiratory rate, breaths/min	20 (20–21)	25 (20–30)	<.001
Consciousness disorders	2 (1.6)	30 (24.8)	<.001
Histories
Hypertension	62 (50.4)	76 (63.3)	.042
Diabetes	24 (19.5)	27 (22.5)	.567
Coronary heart disease	15 (12.2)	20 (16.7)	.321
Previous respiratory diseases	4 (3.3)	20 (16.7)	<.001
Durations
Time from illness onset to hospital admission, d	11 (7–15)	11 (7–15)	.871
Time from illness onset to outcome, d	32 (26–38)	19 (15–25)	<.001
Laboratory values
WBC count, ×10⁹/L	5.37 (4.43–6.70)	10.15 (6.20–13.41)	<.001
LYM count, ×10⁹/L	0.95 (0.70–1.34)	0.51 (0.35–0.72)	<.001
NT-proBNP, ×10² pg/mL	1.74 (0.75–3.60)	8.24 (3.50–25.68)	<.001
PCT, ng/mL	0.05 (0.03–0.09)	0.36 (0.14–1.01)	<.001
hs-TnI, pg/mL	6.2 (3.5–12.6)	40.1 (12.3–239.4)	<.001
D-dimer, μg/mL FEU	0.79 (0.47–1.63)	4.16 (1.49–21.00)	<.001
ALT, U/L	22 (14–36)	28 (19–42)	.009
AST, U/L	28 (20–39)	45 (30–64)	<.001
Creatinine, μmol/L	66 (54–82)	90 (76–118)	<.001
eGFR, mL/min/1.73 m²	89.0 (73.4–94.5)	69.9 (44.7–81.4)	<.001
hs-CRP, mg/L	39.8 (8.3–79.6)	105.4 (65.0–165.2)	<.001
ESR, mm/h	36.0 (20.0–59.0)	37.0 (20.0–60.0)	.956
Serum ferritin, ×10² μg/L	5.2 (3.9–8.8)	16.1 (9.7–24.6)	<.001
Interleukin-6, pg/mL	12.7 (3.3–41.5)	75.2 (35.2–162.9)	<.001

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; eGFR, estimated glomerular filtration rate; ESR, erythrocyte sedimentation rate; hs-CRP, high-sensitivity C-reactive protein; hs-TnI, high-sensitivity cardiac troponin I; LYM, lymphocyte; NT-proBNP, amino-terminal pro-brain natriuretic peptide; PCT, procalcitonin; SpO₂, oxygen saturation; WBC, white blood cell; FEU, fibrinogen equivalent units.
^aData presented as median (interquartile range) and number (percentage) for continuous and categorical variables, respectively, unless otherwise indicated.

Table 2. Multivariate Analysis of Risk Factors for Mortality
Risk Factor	OR	95% CI for OR		P Value
Risk Factor	OR	Lower	Upper	P Value
Demographics
Age, y	1.12	1.01	1.25	.037
Sex (female vs male)	0.32	0.04	2.41	.270
Vital signs
SpO₂, %	0.97	0.86	1.09	.565
Heart rate, beats/min	1.00	0.96	1.04	.977
Respiratory rate, breaths/min	1.13	0.94	1.35	.181
Consciousness disorders (disorders vs clear)	1.38	0.08	24.00	.827
Histories
Hypertension (yes vs no)	0.82	0.24	2.75	.744
Previous respiratory diseases (yes vs no)	3.24	0.45	23.57	.245
Laboratory values
WBC count, ×10⁹/L	1.28	1.00	1.64	.052
LYM count, ×10⁹/L	0.01	0.00	0.14	.001
NT-proBNP, ×10² pg/mL	1.00	1.00	1.00	.514
PCT, ng/mL	0.96	0.73	1.27	.791
hs-TnI, pg/mL	1.03	1.00	1.07	.065
D-dimer, μg/mL FEU	1.07	0.95	1.22	.278
ALT, U/L	0.98	0.94	1.02	.231
AST, U/L	1.04	0.99	1.09	.137
Creatinine, μmol/L	1.04	0.96	1.13	.340
eGFR, mL/min/1.73 m²	1.04	0.92	1.16	.543
hs-CRP, mg/L	1.01	1.00	1.02	.122

Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; CI, confidence interval; eGFR, estimated glomerular filtration rate; hs-CRP, high-sensitivity C-reactive protein; hs-TnI, high-sensitivity cardiac troponin I; LYM, lymphocyte; NT-proBNP, amino-terminal pro-brain natriuretic peptide; OR, odds ratio; PCT, procalcitonin; SpO₂, oxygen saturation; WBC, white blood cell; FEU, fibrinogen equivalent units.