4. Summary of studies reporting outcomes stratified according to different corticosteroid regimens.
| Subgroup analysis | Study | Outcome | Comments |
| Early and late CS therapy compared with no CS therapy | Brun‐Buisson 2011 | Hospital mortality Early CS: HR 3.42, 95% CI 1.73 to 6.75; P = 0.001 Late CS: HR 1.93, 95% CI 0.84 to 4.43; P = 0.12 |
Early treatment defined as "within 3 days of mechanical ventilation". Propensity score adjusted analysis |
| Early CS therapy versus late/no CS therapy groups combined | Han 2011 | Critical illness RR 1.8, 95% CI 1.2 to 2.8 |
Early treatment defined as < 72 hours from influenza‐like illness. Multivariate analysis following adjustment for underlying comorbid illnesses, age, pregnancy, and obesity |
| Low‐dose versus high‐dose CS therapy | Xi 2010 | In‐hospital mortality 9/30 versus 8/22, P = 0.854 |
Low‐dose CS therapy defined as ≤ 80 mg methylprednisolone or equivalent daily dose. Unadjusted outcome |
| Low‐moderate‐dose and high‐dose CS therapy compared with no CS therapy | Cao 2016 | 30‐day mortality Low‐moderate‐dose CS: HR 1.64, 95% CI 0.79 to 3.39; P = 0.183 High‐dose CS: HR 3.05, 95% CI 1.28 to 7.25; P = 0.012 |
Low‐moderate‐dose CS therapy defined as 25 to 150 mg/day methylprednisolone or equivalent. High‐dose CS therapy defined as > 150 mg/day methylprednisolone or equivalent. Adjusted outcome |
| Low‐moderate‐dose and high‐dose CS therapy compared with no CS therapy | Cao 2016 | Viral shedding (median days) Any dose CS = 14 (12 to 17) versus control = 12 (11 to 15); P = 0.027 Low‐moderate‐dose CS = 13 (10.3 to 16) versus control = 12 (10.5 to 15); P = 0.252 High‐dose CS = 15 (13.5 to 20) versus control = 13 (10.8 to 15.3); P = 0.039 |
Low‐moderate‐dose CS therapy defined as 25 to 150 mg/day methylprednisolone or equivalent. High‐dose CS therapy defined as > 150 mg/day methylprednisolone or equivalent. Propensity score adjusted analyses |
| Low‐dose versus high‐dose CS therapy and stratification by hypoxic status | Li 2017 |
30‐day mortality all participants Any dose CS: aHR 0.80, 95% CI 0.56 to 1.15; P = 0.230 Low‐moderate‐dose CS: aHR 0.64, 95% CI 0.43 to 0.96; P = 0.033 High‐dose CS: aHR 0.91, 95% CI 0.58 to 1.44; P = 0.694 30‐day mortality, only participants with PaO2/FiO2< 300 mmHg Any dose CS: aHR 0.67, 95% CI 0.46 to 0.98; P = 0.038 Low‐moderate‐dose CS: aHR 0.49, 95% CI 0.32 to 0.77; P = 0.002 High‐dose CS: aHR 0.88, 95% CI 0.56 to 1.39; P = 0.581 30‐day mortality, only participants with PaO2/FiO2 ≥ 300 mmHg Any dose CS: aHR 2.43, 95% CI 0.82 to 7.15; P = 0.108 Low‐moderate‐dose CS: aHR 3.09, 95% CI 0.95 to 10.12; P = 0.062 High‐dose CS: aHR 1.70, 95% CI 0.23 to 12.65; P = 0.605 |
Low‐moderate‐dose CS therapy defined as 25 to 150 mg/day methylprednisolone or equivalent. High‐dose CS therapy defined as > 150 mg/day methylprednisolone or equivalent. |
aHR: adjusted hazard ratio CI: confidence interval CS: corticosteroid HR: hazard ratio PaO2/FiO2: ratio of partial pressure of oxygen in arterial blood to inspired fraction of oxygen RR: risk ratio