Experience with corticosteroids: severe influenza virus infection and coronavirus disease 2019 (COVID-19)
| Influenza study/country | Population | Control | Outcomes |
| Cao et al. 2016 [137]/China | 204 patients with influenza A (H7N9) virus pneumonia | 84 patients with influenza A (H7N9) virus pneumonia did not receive corticosteroids | High-dose corticosteroids were associated with increased mortality and longer viral shedding. |
| Moreno et al. 2018 [138]/USA | 604 patients with severe influenza pneumonia received corticosteroids | 1242 patients with severe influenza pneumonia did not receive corticosteroids | Corticosteroids associated with increased ICU mortality. |
| Ni et al. 2019 [139]/China | 2564 patients with influenza pneumonia received corticosteroids | 3984 patients with influenza pneumonia did not receive corticosteroids | Corticosteroids increased mortality, ICU LOS, and the rate of secondary infection. However, it did not influence MV days. |
| Zhou et al. 2020 [140]/China | 2675 patients with influenza pneumonia or ARDS received corticosteroids | 3962 patients with influenza pneumonia did not receive corticosteroids | The use of corticosteroids increased mortality and incidence of nosocomial infection. However, it did not influence LOS. |
| Okuno et al. 2021 [141]/Japan | 875 patients with influenza pneumonia and respiratory failure received corticosteroids | 2644 patients with influenza pneumonia and respiratory failure did not receive corticosteroids | In-hospital mortality rate was higher in the group receiving corticosteroids. |
| COVID-19 study/country | Population | Control | Outcomes |
| RECOVERY Collaborative Group et al. 2021 [142]/UK | 2104 hospitalised patients with COVID-19 received dexamethasone | 4321 hospitalised patients with COVID-19 received usual care | The use of 6 mg of dexamethasone per day for 10 days in patients with COVID-19 requiring oxygen therapy resulted in a reduction in all-cause, 28-day mortality (p<0.001). In patients not requiring oxygen, no benefit was observed: 28-day mortality rates were 17.8% and 14% for the dexamethasone and routine care groups, respectively. |
| WHO Rapid Evidence Appraisal for COVID-19 Therapies (react) Working Group et al. 2020 [143]/12 countries | 678 critically ill COVID-19 patients received receive systemic dexamethasone, hydrocortisone or methylprednisolone | 1025 critically ill COVID-19 patients received usual care or placebo | The administration of corticosteroids was associated with lower all-cause, 28-day mortality, compared with routine care or placebo. |
| Liu et al. 2020 [144]/China | 409 patients with severe COVID-19 related to ARDS received corticosteroids | 365 patients with severe COVID-19 related to ARDS did not receive corticosteroids | Corticosteroid use was associated with a higher 28-day mortality rate and a delay in SARS-CoV-2 RNA clearance. |
| van Paassen et al. 2020 [146]/The Netherlands | A systemic review and meta-analysis 20 197 patients with COVID-19 requiring either oxygen therapy or mechanical ventilation | NA | A beneficial effect of corticosteroids on short-term mortality and a reduction in need for mechanical ventilation were reported. |
| Fadel et al. 2020 [147]/USA | 132 patients with moderate to severe COVID-19 received early corticosteroids | 81 patients with moderate to severe COVID-19 received standard care | An early short course of methylprednisolone in moderate to severe COVID-19 showed a reduction in escalation of care and improved clinical outcomes. |
| Monedero et al. 2021 [148]/Spain | 485 critically ill patients with COVID-19 received early corticosteroids | 397 critically ill patients received non-early corticosteroids | Early use of corticosteroids in critically ill patients with COVID-19 was associated with lower mortality than delayed use. |
ARDS: acute respiratory distress syndrome; ICU: intensive care unit; LOS: length of stay; MV: mechanical ventilation; NA: not applicable; WHO: World Health Organization; SARS-CoV-2: severe acute respiratory syndrome coronavirus 2.