Risk factors and interventions associated with mortality or survival in adult COVID-19 patients admitted to critical care: a systematic review and meta-analysis

Patients with confirmed COVID-19 admitted to intensive care units have a high mortality rate, which appears to be associated with increasing age, male sex, smoking history, hypertension and diabetes mellitus. Methods: A systematic review to determine risk factors and interventions associated with mortality/survival in adult patients admitted to an intensive care unit (ICU) with confirmed COVID-19/SARS-CoV-2 infection. The protocol was registered with PROSPERO (CRD42020181185).Results: The search identified 483 abstracts between 1 January and 7 April 2020, of which nine studies were included in the final review. Only one study was of low bias. Advanced age (odds ratio [OR] 11.99, 95% confidence interval [CI] 5.35­18.62) and a history of hypertension were associated with mortality (OR 4.17, 95% CI 2.90­5.99). Sex was not associated with mortality. There was insufficient data to assess the association between other comorbidities, laboratory results or critical care risk indices and mortality.The critical care interventions of mechanical ventilation (OR 6.25, 95% CI 0.75­51.93), prone positioning during ventilation (OR 2.06, 95% CI 0.20­21.72), and extracorporeal membrane oxygenation (ECMO) (OR 8.00, 95% CI 0.69, 92.33) were not associated with mortality. The sample size was insufficient to conclusively determine the association between these interventions and ICUmortality. The need for inotropes or vasopressors was associated with mortality (OR 6.36, 95% CI 1.89­21.36). Conclusion: The studies provided little granular data to inform risk stratification or prognostication of patients requiring intensive