Retrospective analysis of risk factors associated with mortality in hospitalized COVID-19 patients

Abstract

Background: Older age and comorbidities are associated with adverse outcomes in patients with coronavirus disease 2019 (COVID-19); however, comprehensive identification of mortality risk factors can further guide disease management. We aimed to analyze predictors of in-hospital mortality in hospitalized COVID-19 patients.

Methods: This retrospective cohort study included 400 COVID-19 patients admitted between March and December 2020. Demographics, vital signs, medical history, presenting symptoms, laboratory findings, treatments, and outcomes were extracted from the patient's electronic medical records. Patients were stratified into survivor (n = 300) and nonsurvivor (n = 100) groups. Univariate and multivariate logistic regressions were used to analyze associations between variables and mortality.

Results: Nonsurvivors were older (mean age 65 vs 45 years) and had more hypertension (60% vs 33%), diabetes (40% vs 20%), chronic obstructive pulmonary disease (20% vs 5%), and chronic kidney disease (15% vs 3%). Shorter symptom onset to admission (7 vs 4 days), lower oxygen saturation (92% vs 96%), lymphopenia, and elevated inflammatory and coagulation markers were also associated with mortality (all P < 0.001). Mechanical ventilation (60% vs 3%) and therapeutic anticoagulation were more common in nonsurvivors (all P < 0.001). Age over 75 years (adjusted odds ratio 5.2), chronic medical conditions, elevated D-dimer, and mechanical ventilation had the strongest independent associations with mortality (P < 0.001).

Conclusions: Older age, comorbidities such as chronic pulmonary and renal disease, disease severity parameters such as dysregulated inflammatory and coagulation markers, and the need for aggressive interventions predict increased mortality risk in hospitalized COVID-19 patients.

Keywords: COVID-19; D-dimer; lymphocytes; mechanical ventilation; mortality; risk factors.