Comparing ICU admission rates of mild/moderate COVID-19 patients treated with hydroxychloroquine, favipiravir, and hydroxychloroquine plus favipiravir

J Infect Public Health. 2021 Mar;14(3):365-370. doi: 10.1016/j.jiph.2020.12.017. Epub 2020 Dec 29.


Background: In this study, we aimed to compare the intensive care unit (ICU) admission rate of hospitalized mild/moderate COVID-19 patients treated with hydroxychloroquine (HCQ), favipiravir, and HCQ plus favipiravir.

Methods: Single center retrospective designed observational study conducted in Ankara City Hospital. Patients who were hospitalized between March 15, 2020 and June 1, 2020 in COVID-19 inpatient clinics with laboratory confirmed diagnosis of COVID-19 were included in the study. An inverse probability of treatment weighting (IPTW) for multiple treatment groups approach was used to balance the differences in several variables on admission.

Results: Among 2441 patients hospitalized with diagnosis of COVID-19 during the study period, 824 were eligible for the analysis. Median age of patients was 42 (18-93 years). Among all, 347 (43.2%) of the patients had mild disease, 470 (56.8%) had pneumonia. Propensity scores ranged from 0.1841 to 0.9381 in the HCQ group, from 0.03643 to 0.29885 in the favipiravir group, and from 0.03542 to 0.56184 in the HCQ plus favipiravir group. After IPTW for multiple treatment groups was applied, all the covariates in the planned propensity score had weighted standardized effect sizes below 10% which were ranged from 0.005 to 0.092. Multivariate analysis of treatment effect (adjusted effect of treatment) was indicated that there is no statistically significant difference between HCQ, favipiravir, and HCQ plus favipiravir treatment. After using combination of SMOTE and Bootstrap resampling approach, we found no statistically significant difference between HCQ and HCQ plus favipiravir groups in terms of ICU admission. However, compared with the HCQ group, ICU admission rate was statistically significantly higher in the favipiravir group. We obtained the similar results after the sensitivity analysis.

Conclusions: HCQ with or without favipiravir treatment is associated with reduced risk of ICU admission compared to favipiravir alone in mild to moderate COVID-19 adult patients.

Keywords: COVID-19; Favipiravir; Hydroxychloroquine; ICU; Treatment.

Publication types

  • Observational Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Amides* / therapeutic use
  • Antiviral Agents* / therapeutic use
  • COVID-19 / drug therapy*
  • Drug Therapy, Combination
  • Female
  • Humans
  • Hydroxychloroquine* / therapeutic use
  • Intensive Care Units / statistics & numerical data*
  • Male
  • Middle Aged
  • Pyrazines* / therapeutic use
  • Retrospective Studies
  • Treatment Outcome
  • Young Adult


  • Amides
  • Antiviral Agents
  • Pyrazines
  • Hydroxychloroquine
  • favipiravir

Supplementary concepts

  • COVID-19 drug treatment