COVID-19: 6-continent study finds increased mortality risk with hydroxychloroquine

  • Mehra MR, & et al
  • Lancet
  • 23 May 2020

  • curated by Liz Scherer
  • Clinical Essentials
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This article has been retracted.

Takeaway

  • In this large multinational study covering 6 continents, chloroquine or hydroxychloroquine alone or with a macrolide was linked to increased in-hospital mortality risk for patients with COVID-19.
  • Risk for ventricular arrhythmia (VA) was also associated with the drugs.

Why this matters

  • Editorial: although the study is observational, the results "indicate an absence of benefit" from these treatments and "suggest that they could even be harmful."

Key results

  • 96,032 patients with COVID-19 at 671 hospitals.
  • Mean age, 53.8 years (standard deviation [SD]: ±17.6); 46.3% (44,426) women.
  • In-hospital mortality rates and risks (95% CIs):
    • 9.3% controls (reference).
    • 18.0% hydroxychloroquine.
      • HR, 1.33 (1.22-1.45). 
    • 23.8% hydroxychloroquine+macrolide.
      • HR, 1.44 (1.36-1.53).
    • 16.4% chloroquine.
      • HR, 1.36 (1.21-1.53). 
    • 22.2% chloroquine+macrolide.
      • HR, 1.36 (1.27-1.46).
  • Rates and risks (95% CIs) for new VA:
    • 0.3% controls (reference).
    • 6.1% hydroxychloroquine.
      • HR, 2.36 (1.93-2.90). 
    • 8.1% hydroxychloroquine+macrolide.
      • HR, 5.10 (4.10-5.98).
    • 4.3% chloroquine.
      • HR, 3.56 (2.76-4.59).
    • 6.5% chloroquine+macrolide.
      • HR, 4.01 (3.34-4.81).

Study design

  • Multinational observational registry analysis of chloroquine or hydroxychloroquine alone or combined with a macrolide.
  • Treatments (±SD): 
    • Hydroxychloroquine (n=3016): 596 mg/day (±126) every 4.2 days (±1.9). 
    • Hydroxychloroquine+macrolide (n=6221): 597 mg/day (±128) every 4.3 days (±2.0).
    • Chloroquine (n=1868): 765 mg/day (±308) every 6.6 days (±2.4). 
    • Chloroquine+macrolide (n=3783): 790 mg/day (±320) every 6.8 days (±2.5). 
  • Funding: Brigham and Women’s Hospital, Boston, MA, USA.

Limitations

  • Observational. 
  • Unmeasured confounders