Conv. Plasma
Nigella Sativa

All HCQ studies
Meta analysis
study COVID-19 treatment researchHCQHCQ (more..)
Melatonin Meta
Azvudine Meta Metformin Meta
Bromhexine Meta
Budesonide Meta Molnupiravir Meta
Colchicine Meta
Conv. Plasma Meta
Curcumin Meta Nigella Sativa Meta
Famotidine Meta Nitazoxanide Meta
Favipiravir Meta Paxlovid Meta
Fluvoxamine Meta Quercetin Meta
Hydroxychlor.. Meta Remdesivir Meta
Ivermectin Meta
Lactoferrin Meta

All Studies   Meta Analysis   Recent:  
0 0.5 1 1.5 2+ Mortality -9% Improvement Relative Risk HCQ for COVID-19  Peters et al.  LATE TREATMENT Is late treatment with HCQ beneficial for COVID-19? Retrospective 1,949 patients in Netherlands No significant difference in mortality Peters et al., Clinical Microbiology a.., Aug 2020 Favors HCQ Favors control

Outcomes of Persons With COVID-19 in Hospitals With and Without Standard Treatment With (Hydroxy)chloroquine

Peters et al., Clinical Microbiology and Infection, doi:10.1016/j.cmi.2020.10.004 (date from preprint)
Aug 2020  
  Source   PDF   All Studies   Meta AnalysisMeta
Retrospective study of HCQ use in 9 hospitals in the Netherlands, showing no significant difference in mortality with HCQ/CQ or dexamethasone. Late stage (admitted to hospital with positive test or CT scan abnormalities). 4 of 7 hospitals started treatment only after further deterioration. Short cutoff (21 days) - other studies have shown treated patient cases resolved faster and more control patients remaining in hospital at this time.
In the preprint, 58 of 341 control patients died. In the journal version, 53 of 353 control patients died.
Significant differences between hospitals - HCQ hospitals had significantly older patients with significantly more comorbidities. Non-HCQ hospitals were "tertiary academic centres" whereas HCQ hospitals were "secondary care hospitals". Residual confounding likely. This study compares overcrowded regular hospitals with undercrowded academic hospitals.
A subset of patients were excluded due to transfer to other hospitals. This introduces bias because patients in critical condition are not transferred. For examples, patients benefiting from HCQ treatment may have been transferred to the tertiary centres and excluded from analysis, increasing the percentage of critical cases in the secondary hospitals.
Among the seven (H)CQ-hospitals, the timing of start of (H)CQ treatment differed; three hospitals started at the moment of COVID-19 diagnosis, four started after diagnosis but only when patients clinically deteriorated e.g., when there was an increase in respiratory rate or increase in use of supplemental oxygen.
Most patients received CQ instead of the safer HCQ, receiving late treatment with CQ. Patients were given an initial dose of 600mg CQ then every 12 hours, for 5 days a dose of 300 mg, for a total of 3600mg CQ. This dose is likely to be toxic, see for example
Authors mention a subset of hospitals started treatment relatively earlier, which seems like the most important area to analyze, but no results are provided.
This study is excluded in the after exclusion results of meta analysis: excessive unadjusted differences between groups.
risk of death, 9.0% higher, HR 1.09, p = 0.57, treatment 419 of 1,596 (26.3%), control 53 of 353 (15.0%), adjusted per study.
Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
Peters et al., 15 Aug 2020, retrospective, Netherlands, peer-reviewed, 21 authors.
All Studies   Meta Analysis   Submit Updates or Corrections
This PaperHCQAll
Outcomes of persons with coronavirus disease 2019 in hospitals with and without standard treatment with (hydroxy)chloroquine
Edgar Jg. Peters, Didier Collard, Sander Van Assen, Martijn Beudel, Marije K Bomers, Jacqueline Buijs, Lianne R De Haan, Wouter De Ruijter, Renée A Douma, Paul Wg. Elbers, Abraham Goorhuis, Niels C Gritters Van Den Oever, Lieve Ghh. Knarren, Hazra S Moeniralam, Remy Lm. Mostard, Marian Jr. Quanjel, Auke C Reidinga, Roos Renckens, Joop Pw. Van Den Bergh, Imro N Vlasveld, Jonne J Sikkens
Clinical Microbiology and Infection, doi:10.1016/j.cmi.2020.10.004
Objective: To compare survival of individuals with coronavirus disease 2019 (COVID-19) treated in hospitals that either did or did not routinely treat patients with hydroxychloroquine or chloroquine. Methods: We analysed data of COVID-19 patients treated in nine hospitals in the Netherlands. Inclusion dates ranged from 27 February to 15 May 2020, when the Dutch national guidelines no longer supported the use of (hydroxy)chloroquine. Seven hospitals routinely treated patients with (hydroxy)chloroquine, two hospitals did not. Primary outcome was 21-day all-cause mortality. We performed a survival analysis using log-rank test and Cox regression with adjustment for age, sex and covariates based on premorbid health, disease severity and the use of steroids for adult respiratory distress syndrome, including dexamethasone. Results: Among 1949 individuals, 21-day mortality was 21.5% in 1596 patients treated in hospitals that routinely prescribed (hydroxy)chloroquine, and 15.0% in 353 patients treated in hospitals that did not. In the adjusted Cox regression models this difference disappeared, with an adjusted hazard ratio of 1.09 (95% CI 0.81e1.47). When stratified by treatment actually received in individual patients, the use of (hydroxy)chloroquine was associated with an increased 21-day mortality (HR 1.58; 95% CI 1.24e2.02) in the full model.
Transparency declaration The authors declare that they have no conflicts of interest. Funding D. Collard is supported by a ZonMw grant (project no.: 10430022010002). Contribution of authors All authors have made substantial contributions to the following: the conception and design of the study, or acquisition of data, or analysis and interpretation of data; drafting the article or revising it critically for important intellectual content; and final approval of the version to be submitted. Appendix A. Supplementary data Supplementary data to this article can be found online at
Catteau, Dauby, Montourcy, Bottieau, Hautekiet et al., Low-dose hydroxychloroquine therapy and mortality in hospitalized patients with COVID-19: a nationwide observational study of 8075 participants, Int J Antimicrob Agents
Fan, Zhang, Liu, Yang, Zheng et al., Connecting hydroxychloroquine in vitro antiviral activity to in vivo concentration for prediction of antiviral effect: a critical step in treating COVID-19 patients, Clin Infect Dis
Fantini, Scala, Chahinian, Yahi, Structural and molecular modelling studies reveal a new mechanism of action of chloroquine and hydroxychloroquine against SARS-CoV-2 infection, Int J Antimicrob Agents
Fiolet, Guihur, Rebeaud, Mulot, Peiffer-Smadja et al., Effect of hydroxychloroquine with or without azithromycin on the mortality of COVID-19 patients: a systematic review and meta-analysis, Clin Microbiol Infect
Gautret, Lagier, Parola, Hoang, Meddeb et al., Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an openlabel non-randomized clinical trial, Int J Antimicrob Agents
Geleris, Sun, Platt, Zucker, Baldwin et al., Observational study of hydroxychloroquine in hospitalized patients with Covid-19, N Engl J Med
Group, Horby, Lim, Emberson, Mafham et al., Dexamethasone in hospitalized patients with Covid-19dpreliminary report, N Engl J Med
Horby, Mafham, Linsell, Bell, Staplin et al., Effect of hydroxychloroquine in hospitalized patients with COVID-19: preliminary results from a multi-centre, randomized, controlled trial, medRxiv
Lee, Little, A practical guide to propensity score analysis for applied clinical research, Behav Res Ther
Petrilli, Jones, Yang, Rajagopalan, Donnell et al., Factors associated with hospital admission and critical illness among 5279 people with coronavirus disease 2019 in New York City: prospective cohort study, BMJ
Prokop, Van Everdingen, Van, Vellinga, Quarles Van Ufford et al., CO-RADSda categorical CT assessment scheme for patients with suspected COVID-19: definition and evaluation, Radiology
Risk, Use of hydroxychloroquine in hospitalised COVID-19 patients is associated with reduced mortality: findings from the observational multicentre Italian CORIST study, Eur J Intern Med
Rosenberg, Dufort, Udo, Wilberschied, Kumar et al., Association of treatment with hydroxychloroquine or azithromycin with inhospital mortality in patients with COVID-19 in New York State, JAMA
Tang, Cao, Han, Wang, Chen et al., Hydroxychloroquine in patients with mainly mild to moderate coronavirus disease 2019: open label, randomised controlled trial, BMJ
Wulff, Ejlskov, Multiple imputation by chained equations in Praxis: guidelines and review, Electron J Business Res Meth
Yang, Yu, Xu, Shu, Xia et al., Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a singlecentered, retrospective, observational study, Lancet Respir Med
Yao, Ye, Zhang, Cui, Huang et al., Vitro Antiviral activity and projection of optimized dosing design of hydroxychloroquine for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), Clin Infect Dis
Late treatment
is less effective
Please send us corrections, updates, or comments. c19early involves the extraction of over 100,000 datapoints from thousands of papers. Community updates help ensure high accuracy. Vaccines and treatments are complementary. All practical, effective, and safe means should be used based on risk/benefit analysis. No treatment, vaccine, or intervention is 100% available and effective for all current and future variants. We do not provide medical advice. Before taking any medication, consult a qualified physician who can provide personalized advice and details of risks and benefits based on your medical history and situation. FLCCC and WCH provide treatment protocols.
  or use drag and drop