Summary of COVID-19 dexamethasone studies


1. Horby et al., Dexamethasone in Hospitalized Patients with Covid-19
6,425 patient dexamethasone late treatment RCT: 13% lower mortality (p=0.005), 21% lower ventilation (p=0.03), and 9% higher hospital discharge (p=0.003).
RCT 6,425 hospitalized COVID-19 patients showing lower 28-day mortality with dexamethasone treatment. The benefit was most pronounced in patients who had symptoms for more than 7 days at randomization, suggesting dexamethasone is most effective when the disease is dominated by inflammatory processes rather than viral replication. 6-month results are from [Horby]
Feb 2021, New England J. Medicine, http://www.nejm.org/doi/10.1056/NEJMoa2021436, https://c19p.org/horby5

2. Tomazini et al., Effect of Dexamethasone on Days Alive and Ventilator-Free in Patients With Moderate or Severe Acute Respiratory Distress Syndrome and COVID-19
299 patient dexamethasone late treatment RCT: 3% lower mortality (p=0.85) and 34% improvement (p=0.07).
RCT 299 patients with moderate or severe COVID-19-related ARDS showing increased ventilator-free days with dexamethasone treatment. There was no significant difference in 28-day mortality (56.3% vs 61.5%), ICU-free days, or mechanical ventilation duration.
Oct 2020, JAMA, https://jamanetwork.com/journals/jama/fullarticle/2770277, https://c19p.org/tomazini

3. Mourad et al., Dexamethasone for Inpatients With COVID-19 in a National Cohort
56,368 patient dexamethasone late treatment study: 10% lower mortality (p=0.0002).
PSM retrospective 80,699 hospitalized COVID-19 patients showing reduced mortality or discharge to hospice with dexamethasone in patients requiring supplemental oxygen or mechanical ventilation/ECMO, but no significant difference in patients not requiring supplemental oxygen or on NIPPV.
Apr 2023, JAMA Network Open, https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2803926, https://c19p.org/mourad2

4. Bhat et al., Effectiveness of Dexamethasone for COVID-19 in Hospitalized Patients With Diabetes: A Retrospective Cohort Study
1,058 patient dexamethasone late treatment PSM study: 35% higher mortality (p=0.2) and 46% worse improvement (p=0.02).
Retrospective propensity score matched study of 529 hospitalized diabetic COVID-19 patients showing no significant difference in mortality or clinical improvement with dexamethasone treatment.
Oct 2024, The J. Clinical Endocrinology & Metabolism, https://academic.oup.com/jcem/advance-article/doi/10.1210/clinem/dgae734/7825467, https://c19p.org/bhat2

5. Jamaati et al., No clinical benefit of high dose corticosteroid administration in patients with COVID-19: A preliminary report of a randomized clinical trial
50 patient dexamethasone late treatment RCT: 7% higher mortality (p=1) and 18% higher ventilation (p=0.78).
RCT 50 hospitalized COVID-19 ARDS patients showing no clinical benefit with high-dose dexamethasone.
Apr 2021, European J. Pharmacology, https://www.sciencedirect.com/science/article/pii/S001429992100100X, https://c19p.org/jamaati

6. Bepouka et al., Clinical Characteristics and Mortality Trends Among COVID-19 Patients During the First Four Waves in Ngaliema Clinic, Democratic Republic of the Congo
410 patient dexamethasone late treatment study: 104% higher mortality (p=0.55).
Retrospective 410 hospitalized COVID-19 patients in the Democratic Republic of Congo showing significantly lower mortality with vitamin C treatment.
May 2025, Infection and Drug Resistance, https://www.dovepress.com/clinical-characteristics-and-mortality-trends-among-covid-19-patients--peer-reviewed-fulltext-article-IDR, https://c19p.org/bepoukadex

7. Yen et al., Predictors for cause-specific and timing of deaths in patients with COVID-19: a cohort study in Taiwan
2,196 patient dexamethasone late treatment study: 103% higher mortality (p=0.0002).
Retrospective 2,196 COVID-19 patients in Taiwan (49% mild cases, 44% moderate, 7% severe) showing significantly higher mortality with dexamethasone.
Aug 2024, BMC Infectious Diseases, https://bmcinfectdis.biomedcentral.com/articles/10.1186/s12879-024-09654-w, https://c19p.org/yen3

8. Crothers et al., Dexamethasone in hospitalised COVID-19 patients not on intensive respiratory support
14,950 patient dexamethasone late treatment study: 59% higher mortality (p<0.0001).
IPTW retrospective 19,973 hospitalized COVID-19 patients showing increased 90-day mortality with dexamethasone in patients not on oxygen and no mortality benefit in patients on low-flow nasal cannula. Authors found consistent results across multiple sensitivity analyses. Authors suggest that widespread adoption of dexamethasone for less severely ill COVID-19 patients may cause unintended harm, hypothesizing that early corticosteroid use may impair viral clearance and immune responses important for infection resolution.
Nov 2021, European Respiratory J., https://publications.ersnet.org/lookup/doi/10.1183/13993003.02532-2021, https://c19p.org/crothers

9. Garneau et al., Clinical effects of dexamethasone among patients with sickle cell disease hospitalized with COVID-19: Outcomes from a single academic health system
30 patient dexamethasone late treatment study: 423% higher ICU admission (p=0.14) and 155% longer hospitalization (p=0.06).
Retrospective 30 hospitalized patients with sickle cell disease (SCD) showing increased risk of venous thromboembolism (VTE) with dexamethasone treatment for COVID-19. There were also trends towards increased ICU admission and longer hospital stays with dexamethasone, without statistical significance.
Nov 2024, PLOS ONE, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0313289, https://c19p.org/garneau

10. Horby et al., Higher dose corticosteroids in patients admitted to hospital with COVID-19 who are hypoxic but not requiring ventilatory support (RECOVERY): a randomised, controlled, open-label, platform trial
1,749 patient dexamethasone late treatment RCT: 15% higher mortality (p=0.15) and 46% higher ventilation (p=0.27).
RCT 1,272 hospitalized COVID-19 patients with hypoxia receiving no oxygen or simple oxygen only, showing significantly increased mortality with higher dose dexamethasone compared to usual care (which included low-dose dexamethasone). 6-month results are from [Horby]
May 2023, The Lancet, https://www.sciencedirect.com/science/article/pii/S014067362300510X, https://c19p.org/horby13

11. Franco-Moreno et al., Effect of early administration of dexamethasone in patients with COVID-19 pneumonia without acute hypoxemic respiratory failure and risk of development of acute respiratory distress syndrome: EARLY-DEX COVID-19 trial
126 patient dexamethasone late treatment RCT: 134% higher ventilation (p=0.41), 217% higher ICU admission (p=0.46), 17% higher ARDS (p=0.81), and 3% shorter hospitalization (p=0.88).
RCT 126 hospitalized COVID-19 pneumonia patients not requiring oxygen at admission, showing no significant difference in outcomes with dexamethasone treatment.
Jul 2024, Frontiers in Medicine, https://www.frontiersin.org/articles/10.3389/fmed.2024.1385833/full, https://c19p.org/francomorenodex

12. Kocks et al., A potential harmful effect of dexamethasone in non-severe COVID-19: results from the COPPER-pilot study
6 patient dexamethasone early treatment RCT: 600% worse recovery (p=0.07).
Pilot RCT of 7 outpatients with non-severe COVID-19 suggesting potential harmful effects of dexamethasone treatment. Time to recovery was significantly longer in the dexamethasone group compared to controls (p=0.03). Authors note that systemic corticosteroids, while beneficial for hospitalized COVID-19 patients requiring oxygen, may be harmful in non-severe cases by potentially inhibiting normal immune response when administered too early.
Apr 2022, ERJ Open Research, https://publications.ersnet.org/lookup/doi/10.1183/23120541.00129-2022, https://c19p.org/kocks