Identification of risk factors for in-hospital death of COVID - 19 pneumonia -- lessions from the early outbreak

Abstract

Background: To examine the clinical characteristics and identify independent risk factors for in-hospital mortality of 2019 novel coronavirus (COVID-19) pneumonia.

Methods: A total of 156 patients diagnosed with COVID-19 pneumonia at the Central Hospital of Wuhan from January 29, 2020, to March 20, 2020, and 20 healthy individuals were enrolled in this single-centered retrospective study. The epidemiological parameters, clinical presentations, underlying diseases, laboratory test results, and disease outcomes were collected and analyzed.

Results: The median age of all enrolled patients was 66 years. At least one underlying disease was identified in 101 COVID-19 patients, with hypertension being the most common one, followed by cardiovascular disease and diabetes. The most common symptoms identified upon admission were fever, cough, dyspnea, and fatigue. Compared to survival cases, patients who died during hospitalization had higher plasma levels of D-dimer, creatinine, creatine kinase, lactate dehydrogenase, lactate, and lower percentage of lymphocytes (LYM [%]), platelet count and albumin levels. Most enrolled patients received antibiotics and anti-viral treatment. In addition, 60 patients received corticosteroids, and 51 received intravenous immunoglobulin infusion. Forty-four patients received noninvasive ventilation and 19 received invasive ventilation. Respiratory failure was the most frequently observed complication (106 [67.9%]), followed by sepsis (103 [66.0%]), acute respiratory distress syndrome (ARDS) (67 [42.9%]), and septic shock (50 [32.1%]). Multivariable regression suggested that advanced age (OR [odds ratio] = 1.098, 95% CI [confidence interval]: 1.006-1.199, P = 0.037), shorter duration from onset to admission (OR = 0.853, 95% CI: 0.750-0.969, P = 0.015) and elevated lactate level upon admission (OR = 2.689, 95% CI: 1.044-6.926, P = 0.040) were independent risk factors for in-hospital mortality for COVID-19 infection. Meanwhile, increased LYM (%) at admission (OR = 0.787, 95% CI: 0.686-0.903, P = 0.001) indicated a better prognosis.

Conclusions: In this study, we discovered that age, duration from onset to admission, LYM (%), and lactate level upon admission were independent factors that affecting the in-hospital mortality rate.

Keywords: COVID-19; Characteristics; Risk factors; Survivors; Therapy.

Fig. 1

Kaplan-Meier survival curve for COVID-19 patients with different counts of LYM (%) (P < 0.001) and serum lactate (P = 0.020) (COVID-19, Coronavirus Disease 2019; LYM [%], Percentage of lymphocytes)

Fig. 2

Receiver-operating characteristic of LYM (%), D-dimer and lactate upon hospital admission (AUC, Areas under receiver-operating characteristic curve; LYM[%], Percentage of lymphocytes)