Cochrane reviews and comments on Cochrane reviews

Department of Public Health
University of Helsinki, Finland
harri.hemila@helsinki.fi
http://www.mv.helsinki.fi/home/hemila
Oct 18, 202


    1. Cochrane reviews on vitamin C
      1. The common cold
      2. Pneumonia
      3. Tetanus
    2. Various problems and flaws in other Cochrane reviews

Cochrane reviews on vitamin C

The common cold


On Oct 2022, this review had the Altmetric score 3382, which was position 1439 out of all the 22,246,158 outputs, and 5th of the Cochrane reviews:
https://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2022Oct.htm#score

On June 2020, this review had the Altmetric score 2793, which was position 659 out of all the 15,217,902 outputs:
https://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2020Jun.htm#score

On February 2020, this review had Altmetric score 1944, which was the highest of 10900 Cochrane reviews:

https://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2020Feb.htm#score

On February 2018, this review had Altmetric score 1359, which was the highest of  8855 Cochrane reviews:
https://www.mv.helsinki.fi/home/hemila/AltmetricVitC_Colds_2018Feb.htm#score


Hemilä H, Chalker EB.
Vitamin C for preventing and treating the common cold.
Cochrane Database Syst Rev 2013; CD000980
https://doi.org/10.1002/14651858.CD000980.pub4
https://www.ncbi.nlm.nih.gov/pmc/articles/pmc8078152/
https://helda.helsinki.fi/handle/10138/225864
https://www.mv.helsinki.fi/home/hemila/CC/2013_Coch_Colds_CD000980.pdf
https://www.ncbi.nlm.nih.gov/pubmed/23440782

References to the review and updated 2016 version:
https://www.mv.helsinki.fi/home/hemila/CC

Commentaries on ‘Vitamin C for Preventing and Treating the Common Cold’ with a response from the review author
     [Reply to Bax, Spee and Madderom].
     [Reply to Shamseer and Vohra].
     Evidence-Based Child Health: A Cochrane Review Journal 2008;3:724-728
     https://doi.org/10.1002/ebch.261
     https://helda.helsinki.fi/handle/10138/228088
     https://www.mv.helsinki.fi/home/hemila/H/2008_L_EBCH.pdf


Summary in
French
https://www.mv.helsinki.fi/home/hemila/French.html
https://www.mv.helsinki.fi/home/hemila/French.pdf
German
https://www.mv.helsinki.fi/home/hemila/German.html
https://www.mv.helsinki.fi/home/hemila/German.pdf
Spanish
https://www.mv.helsinki.fi/home/hemila/CD000980_es_abstract.pdf
https://www.mv.helsinki.fi/home/hemila/Spanish.html
https://www.mv.helsinki.fi/home/hemila/Spanish.pdf
Portuguese
https://www.mv.helsinki.fi/home/hemila/Portuguese.html
https://www.mv.helsinki.fi/home/hemila/Portuguese.pdf
Polish
https://www.mv.helsinki.fi/home/hemila/Polski.html
https://www.mv.helsinki.fi/home/hemila/Polski.pdf
Russian
https://www.mv.helsinki.fi/home/hemila/Russian.html
https://www.mv.helsinki.fi/home/hemila/Russian.pdf

Chinese mandarin
https://www.mv.helsinki.fi/home/hemila/Chinese_1.html
https://www.mv.helsinki.fi/home/hemila/Chinese_1.pdf
Chinese old
https://www.mv.helsinki.fi/home/hemila/Chinese_2.html
https://www.mv.helsinki.fi/home/hemila/Chinese_2.pdf
Japanese
https://www.mv.helsinki.fi/home/hemila/Japanese.html
https://www.mv.helsinki.fi/home/hemila/Japanese.pdf
Korean
https://www.mv.helsinki.fi/home/hemila/Korean.html
https://www.mv.helsinki.fi/home/hemila/Korean.pdf
Tamili
https://www.mv.helsinki.fi/home/hemila/Tamili.html
https://www.mv.helsinki.fi/home/hemila/Tamili.pdf
Malay
https://www.mv.helsinki.fi/home/hemila/Malay.html
https://www.mv.helsinki.fi/home/hemila/Malay.pdf



Pneumonia


Three controlled trials have found significant decrease in the incidence of pneumonia and two found treatment benefit for pneumonia patients.
Hemilä H, Louhiala P.
Vitamin C for preventing and treating pneumonia.
Cochrane Database Syst Rev 2013; CD005532

https://doi.org/10.1002/14651858.cd005532.pub3
https://helda.helsinki.fi/handle/10138/225862
https://www.mv.helsinki.fi/home/hemila/CP/2013_Coch_Pneu_CD005532.pdf
https://pubmed.ncbi.nlm.nih.gov/23925826/

References to the review and update 2016:
https://www.mv.helsinki.fi/home/hemila/CP/

Summary in
French
https://www.mv.helsinki.fi/home/hemila/PFrench.html
Spanish
https://www.mv.helsinki.fi/home/hemila/CD005532_es_abstract.pdf
https://www.mv.helsinki.fi/home/hemila/PSpanish.html
Chinese 
https://www.mv.helsinki.fi/home/hemila/PChinese.html
Japanese
https://www.mv.helsinki.fi/home/hemila/PJapanese.html
Korean
https://www.mv.helsinki.fi/home/hemila/PKorean.html



Tetanus


Hemilä H, Koivula T.
Vitamin C for preventing and treating tetanus.
Cochrane Database of Systematic Reviews 2013;11:CD006665
https://doi.org/10.1002/14651858.CD006665.pub3
https://helda.helsinki.fi/handle/10138/225863
https://www.mv.helsinki.fi/home/hemila/CT/2013_Coch_Tetanus_CD006665.pdf
References to the review:
https://www.mv.helsinki.fi/home/hemila/CT/

Summary in
French
https://www.mv.helsinki.fi/home/hemila/TFrench.html
Spanish
https://www.mv.helsinki.fi/home/hemila/CD006665_es_abstract.pdf
https://www.mv.helsinki.fi/home/hemila/TSpanish.html
Japanese
https://www.mv.helsinki.fi/home/hemila/TJapanese.html
Korean
https://www.mv.helsinki.fi/home/hemila/TKorean.html



Various problems and flaws in other Cochrane reviews

Cochrane has not consistently followed the COPE guidelines  - THERE WAS NO RESPONSE TO THIS CRITICISM
Eur J Clin Invest 2020
https://doi.org/10.1111/eci.13216
https://pubmed.ncbi.nlm.nih.gov/32077498

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Flaws in a 2020 Cochrane review on vitamin C and pneumonia:
Hemilä H, Chalker E.
Commentary: Vitamin C supplementation for prevention and treatment of pneumonia.
Front Med 2021
https://doi.org/10.3389/fmed.2020.595988

https://www.ncbi.nlm.nih.gov/pmc/articles/pmc7854566/

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Pointing out errors in the Cochrane review and a meta-analysis of 3 exercise-induced asthma trials
The meta-analysis was expanded to BMJ Open paper in 2013

The Cochrane review on vitamin C and asthma misled readers for a decade from 2001 to 2013
Hemilä H. Feedback [on the Cochrane review “vitamin C supplementation for asthma” (2009) by Kaur B, Rowe BH, Stovold E]
Cochrane Database of Systematic Reviews CD000993 [Feedback 24 March 2009]
https://helda.helsinki.fi/handle/10138/38500
https://doi.org/10.13140/2.1.1280.3364
    The above comment was submitted in 2009, but the authors replied no earlier than in 2012.
    Furthermore, the reply was full of errors:
    Hemilä H
    Vitamin C and exercise-induced bronchoconstriction:
    further problems in the Cochrane review "vitamin C for asthma" (2013).
    Unpublished commentary
    http://hdl.handle.net/10138/40816

The Cochrane review on vitamin C and asthma misled readers for a decade from 2001 to 2013.
See the PubMed records of the Cohrane review on vitamin C and asthma from 2001 to 2013:
https://pubmed.ncbi.nlm.nih.gov/11687089/  
2001
https://doi.org/10.1002/14651858.CD000993
ss
https://pubmed.ncbi.nlm.nih.gov/15266435/  
2004
https://doi.org/10.1002/14651858.CD000993.pub2

https://pubmed.ncbi.nlm.nih.gov/19160185/ 
2009
https://doi.org/10.1002/14651858.CD000993.pub3

https://pubmed.ncbi.nlm.nih.gov/24155047/  
2013 Withdrawal of the Cochrane review
https://doi.org/10.1002/14651858.CD000993.pub4

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Hemilä H
Oseltamivir (Tamiflu) shortens the duration of influenza-like illness by 13% (95% CI: 8% to 18%)
[Feedback on the Cochrane review “Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children” by Jefferson T et al.]
Cochrane Database of Systematic Reviews CD008965 [Feedback 6 May 2013]
https://helda.helsinki.fi/handle/10138/42534
https://doi.org/10.1002/14651858.CD008965.pub3

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Problems in the 2011 version of Cochrane review:
Hemilä H.
The zinc for the common cold review by Singh and Das has a number of problems which should be considered when the review is next time updated.

[Feedback on the Cochrane review “Zinc for the common cold review” by Singh and Das]. 2011.
Cochrane Database of Systematic Reviews CD001364 [Feedback 5 September 2011]
Repository of the University of Helsinki
https://helda.helsinki.fi/handle/10138/39188
https://doi.org/10.13140/2.1.4688.2081

Problems in the 2013 version of Cochrane review:
Hemilä H.
Concerns about unattributed copying of text and data, and about numerous other problems in the Cochrane review “Zinc for the Common Cold” by Singh M, Das RR (2013). 2015
Repository of the University of Helsinki
https://hdl.handle.net/10138/153180
https://doi.org/10.5281/zenodo.6394116


    The above comment led to the withdrawal of the Cochrane review, see:
    https://www.cochrane.org/CD001364/ARI_zinc-common-cold
    https://doi.org/10.1002/14651858.CD001364.pub5



The withdrawal of the Cochrane review also led to the retraction of a JAMA summary of the Cochrane review:

Hemilä H.
Common Cold Treatment Using Zinc.
JAMA. 2015;314(7):730.
https://doi.org/10.1001/jama.2015.8174
https://www.ncbi.nlm.nih.gov/pubmed/26284728


    The above JAMA letter pointed out problems in an article by Das and Singh, which was a summary of their Cochrane review.
    As their Cochrane review was withdrawn, their JAMA article was retracted:
    https://doi.org/10.1001/jama.2016.18134
    https://www.ncbi.nlm.nih.gov/pubmed/28027374

    More detailed problems in the Das and Singh JAMA article were described in a longer document:
    https://hdl.handle.net/10138/153617
    https://doi.org/10.5281/zenodo.6393782

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Hemilä H
Antioxidants are not identical and their effects are not uniform over the population.
[Feedback on the Cochrane review “Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases” by Bjelakovic G et al.]
Cochrane Database of Systematic Reviews CD007176 [Feedback 24 August 2009]

https://helda.helsinki.fi/handle/10138/136201
https://doi.org/10.13140/2.1.4426.0641
https://doi.org/10.1002/14651858.CD007176.pub2