Risk factors for in-hospital mortality in laboratory-confirmed COVID-19 patients in the Netherlands: A competing risk survival analysis

Nijman, Gerine; Wientjes, Maike; Ramjith, Jordache; Janssen, Nico; Hoogerwerf, Jacobien; Abbink, Evertine; Blaauw, Marc; Dofferhoff, Ton; van Apeldoorn, Marjan; Veerman, Karin; de Mast, Quirijn; ten Oever, Jaap; Hoefsloot, Wouter; Reijers, Monique H.; van Crevel, Reinout; van de Maat, Josephine S.

BACKGROUND: To date, survival data on risk factors for COVID-19 mortality in western Europe is limited, and none of the published survival studies have used a competing risk approach. This study aims to identify risk factors for in-hospital mortality in COVID-19 patients in the Netherlands, considering recovery as a competing risk. METHODS: In this observational multicenter cohort study we included adults with PCR-confirmed SARS-CoV-2 infection that were admitted to one of five hospitals in the Netherlands (March to May 2020). We performed a competing risk survival analysis, presenting cause-specific hazard ratios (HR(CS)) for the effect of preselected factors on the absolute risk of death and recovery. RESULTS: 1,006 patients were included (63.9% male; median age 69 years, IQR: 58–77). Patients were hospitalized for a median duration of 6 days (IQR: 3–13); 243 (24.6%) of them died, 689 (69.9%) recovered, and 74 (7.4%) were censored. Patients with higher age (HR(CS) 1.10, 95% CI 1.08–1.12), immunocompromised state (HR(CS) 1.46, 95% CI 1.08–1.98), who used anticoagulants or antiplatelet medication (HR(CS) 1.38, 95% CI 1.01–1.88), with higher modified early warning score (MEWS) (HR(CS) 1.09, 95% CI 1.01–1.18), and higher blood LDH at time of admission (HR(CS) 6.68, 95% CI 1.95–22.8) had increased risk of death, whereas fever (HR(CS) 0.70, 95% CI 0.52–0.95) decreased risk of death. We found no increased mortality risk in male patients, high BMI or diabetes. CONCLUSION: Our competing risk survival analysis confirms specific risk factors for COVID-19 mortality in a the Netherlands, which can be used for prediction research, more intense in-hospital monitoring or prioritizing particular patients for new treatments or vaccination.