Related Experiment Video

Updated: Oct 19, 2025

Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure
05:16

Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure

Published on: June 10, 2025

319

Hydroxychloroquine / azithromycin in COVID-19: The association between time to treatment and case fatality rate

Roberto Alfonso Accinelli1, Grisel Jesús Ynga-Meléndez2, Juan Alonso León-Abarca3

  • 1Instituto de Investigaciones de la Altura. Universidad Peruana Cayetano Heredia, Lima, Peru; Facultad de Medicina Alberto Hurtado, Universidad Peruana Cayetano Heredia, Lima, Peru; Hospital Cayetano Heredia, Peru.

Travel Medicine and Infectious Disease
|September 17, 2021
PubMed

Insights

Early hydroxychloroquine and azithromycin treatment for COVID-19 outpatients may reduce mortality. Starting treatment within 72 hours of symptom onset was associated with lower case fatality rates in this study.

Area of Science:

  • Infectious Diseases
  • Pharmacology
  • Epidemiology

Background:

  • No formally accepted pharmacological treatments for COVID-19 currently exist.
  • This study investigates the efficacy of hydroxychloroquine and azithromycin in treating COVID-19 outpatients.

Purpose of the Study:

  • To determine the factors associated with the case-fatality rate in COVID-19 outpatients treated with hydroxychloroquine and azithromycin.
  • To evaluate the impact of treatment timing on COVID-19 patient outcomes.

Main Methods:

  • A retrospective study of 1265 COVID-19 outpatients from Lima, Peru, treated between April 30 and September 30, 2020.
  • Logistic regression analysis was used to identify factors associated with case-fatality.
  • Data collected included patient demographics, SpO2, temperature, comorbidities, symptom duration, and treatment onset.

Main Results:

  • The overall case fatality rate was 0.6%.
  • Factors associated with higher case fatality included older age and lower SpO2.
  • Crucially, no patient treated within the first 72 hours of illness died, and treatment onset was the only factor associated with case fatality in multivariate analysis.

Conclusions:

  • The case fatality rate in COVID-19 outpatients treated with hydroxychloroquine/azithromycin is associated with the timing of treatment initiation.
  • Early intervention (within 72 hours) appears to be a critical factor in improving outcomes for COVID-19 outpatients.
Abstract

Keywords:
AzithromycinCOVID-19HydroxychloroquineMortalitySARS-CoV-2Time-to-Treatment

More Related Videos

Author Spotlight: Advancements in Multiplex Detection of Respiratory Viruses03:53

Author Spotlight: Advancements in Multiplex Detection of Respiratory Viruses

Published on: November 10, 2023

1.5K
An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection08:14

An In Vitro Model for Measuring Immune Responses to Malaria in the Context of HIV Co-infection

Published on: October 6, 2015

10.4K

Related Concept Videos

Causality in Epidemiology01:21

Causality in Epidemiology

Causality or causation is a fundamental concept in epidemiology, vital for understanding the relationships between various factors and health outcomes. Despite its importance, there's no single, universally accepted definition of causality within the discipline. Drawing from a systematic review, causality in epidemiology encompasses several definitions, including production, necessary and sufficient, sufficient-component, counterfactual, and probabilistic models. Each has its strengths and...
1.1K
Comparing the Survival Analysis of Two or More Groups01:20

Comparing the Survival Analysis of Two or More Groups

Survival analysis is a cornerstone of medical research, used to evaluate the time until an event of interest occurs, such as death, disease recurrence, or recovery. Unlike standard statistical methods, survival analysis is particularly adept at handling censored data—instances where the event has not occurred for some participants by the end of the study or remains unobserved. To address these unique challenges, specialized techniques like the Kaplan-Meier estimator, log-rank test, and...
350
Time Course of Drug Effect01:14

Time Course of Drug Effect

The progression of a drug's impact can be analyzed by examining both the concentration-time course and the effect-time course. The concentration-time course is determined by the drug's half-life and is influenced by factors such as its pharmacokinetics, including absorption, distribution, metabolism, and elimination. The effect of the drug is often related to its concentration in the plasma and is calculated using the maximum drug effect and the plasma concentration that generates 50...
2.3K
Hazard Ratio01:12

Hazard Ratio

The hazard ratio (HR) is a widely used measure in clinical trials to compare the risk of events, such as death or disease recurrence, between two groups over time. It reflects the ratio of hazard rates—the instantaneous risk of the event occurring—between a treatment group and a control group. This measure provides valuable insights into the relative effectiveness of a treatment by assessing how the risk of an event differs between the two groups.
For example, in a clinical trial...
299
Assumptions of Survival Analysis01:15

Assumptions of Survival Analysis

Survival models analyze the time until one or more events occur, such as death in biological organisms or failure in mechanical systems. These models are widely used across fields like medicine, biology, engineering, and public health to study time-to-event phenomena. To ensure accurate results, survival analysis relies on key assumptions and careful study design.
218
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response01:15

Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response

Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
160