SynthesisEuropean journal of epidemiology2022
Systematic review and meta-analysis of randomized trials of hydroxychloroquine for the prevention of COVID-19.
Synthesis in European journal of epidemiology, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 22 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
22 citing papers in PubMed, 3 syntheses or guidelines pooled it, 42 citations in OpenAlex.
- Pooled it
- Risk of COVID-19 infection and the associated hospitalization, ICU admission and mortality in opioid use disorder: a systematic review and meta-analysis.Addiction science & clinical practice · 2022Pooled it
- Systematic review and meta-analysis of randomized trials of hydroxychloroquine for the prevention of COVID-19.European journal of epidemiology · 2022Pooled it
- Effect of Tenofovir Alafenamide Fumarate on the outcomes of hospitalized COVID-19 patients: a prospective, block-balanced, open-label, randomized controlled trial.BMC pharmacology & toxicology · 2024Trial
- Evaluation of hydroxychloroquine or chloroquine for the prevention of COVID-19 (COPCOV): A double-blind, randomised, placebo-controlled trial.PLoS medicine · 2024Trial
- Daily tenofovir disoproxil fumarate/emtricitabine and hydroxychloroquine for pre-exposure prophylaxis of COVID-19: a double-blind placebo-controlled randomized trial in healthcare workers.Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases · 2023Trial
- PRL2 negatively regulates FcεRI mediated activation of mast cells.Cell death & disease · 2025Article
- The efficacy and safety of hydroxychloroquine for COVID-19 prophylaxis and clinical assessment: an updated meta-analysis of randomized trials.Journal of thoracic disease · 2024Article
- Quercetin inhibits SARS-CoV-2 infection and prevents syncytium formation by cells co-expressing the viral spike protein and human ACE2.Virology journal · 2024Article
- Investigational medications in 9,638 hospitalized patients with severe COVID-19: lessons from the "fail-and-learn" strategy during the first two waves of the pandemic in 2020.Patient safety in surgery · 2023Article
- Drug Repurposing and Observational Studies: The Case of Antivirals for the Treatment of COVID-19.Annals of internal medicine · 2023Review
- Review
- COVID-19: Understanding the impact of anti-hypertensive drugs and hydroxychloroquine on the ACE1 and ACE2 in lung and adipose tissue in SHR and WKY rats.Physiological reports · 2023Article
- High-cited favorable studies for COVID-19 treatments ineffective in large trials.Journal of clinical epidemiology · 2022Article
- Does hydroxychloroquine still have any role in the COVID-19 pandemic?Expert opinion on pharmacotherapy · 2021Article
- A tale of two diseases: Sarcoidosis, COVID-19 and new therapeutic options with dual RAS inhibition and tetanus-diphtheria vaccine.Medical hypotheses · 2021Article
- Hydroxychloroquine as a primary prophylactic agent against SARS-CoV-2 infection: A cohort study.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2021Article
- COVID-19 chemoprevention.International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2021Article
- The Rise and Fall of Hydroxychloroquine for the Treatment and Prevention of COVID-19.The American journal of tropical medicine and hygiene · 2021Article
- The WHO guideline on drugs to prevent COVID-19: small numbers- big conclusions.Wellcome open research · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundRecruitment into randomized trials of hydroxychloroquine (HCQ) for prevention of COVID-19 has been adversely affected by a widespread conviction that HCQ is not effective for prevention. In the absence of an updated systematic review, we conducted a meta-analysis of randomized trials that study the effectiveness of HCQ to prevent COVID-19.
methodsA search of PubMed, medRxiv, and clinicaltrials.gov combined with expert consultation found 11 completed randomized trials: 7 pre-exposure prophylaxis trials and 4 post-exposure prophylaxis trials. We obtained or calculated the risk ratio of COVID-19 diagnosis for assignment to HCQ versus no HCQ (either placebo or usual care) for each trial, and then pooled the risk ratio estimates.
resultsThe pooled risk ratio estimate of the pre-exposure prophylaxis trials was 0.72 (95% CI: 0.58-0.90) when using either a fixed effect or a standard random effects approach, and 0.72 (95% CI: 0.55-0.95) when using a conservative modification of the Hartung-Knapp random effects approach. The corresponding estimates for the post-exposure prophylaxis trials were 0.91 (95% CI: 0.72-1.16) and 0.91 (95% CI: 0.62-1.35). All trials found a similar rate of serious adverse effects in the HCQ and no HCQ groups. DISCUSSION: A benefit of HCQ as prophylaxis for COVID-19 cannot be ruled out based on the available evidence from randomized trials. However, the "not statistically significant" findings from early prophylaxis trials were widely interpreted as definite evidence of lack of effectiveness of HCQ. This interpretation disrupted the timely completion of the remaining trials and thus the generation of precise estimates for pandemic management before the development of vaccines.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.