Feedback on: Kaur B, Rowe BH, Arnold E. Vitamin C supplementation for asthma. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD000993.

This is Feedback on the following Cochrane review: Kaur B, Rowe BH, Arnold E. Vitamin C supplementation for asthma. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD000993. pubmed/19160185 doi: 10.1002/14651858.CD000993.pub3

This Feedback was published within the Cochrane review, see: https://helda.helsinki.fi/handle/10138/296440

The first version of the Cochrane review was published in 2001: Kaur B, Rowe BH, Ram FS. Vitamin C supplementation for asthma.
Cochrane Database Syst Rev. 2001;(4):CD000993. pubmed/11687089
The second version of the Cochrane review was published in 2004: Ram FS, Rowe BH, Kaur B. Vitamin C supplementation for asthma.Cochrane Database Syst Rev. 2004;(3):CD000993. pubmed/15266435

This Feedback below points out errors in Analyses 1.1, 1.2, 1.3 and 1.5 of the Cochrane review (2009 version). However, all these analyses were identical already in the first version (2001) of the Cochrane review. Thus, because of the errors described in this feedback, the Cochrane review “Vitamin C supplementation for asthma” had been misleading readers for a decade.

In addition to the problems described in this Feedback (2009) below, there are a number of additional problems in the Cochrane review “vitamin C supplementation for asthma” (2009), which are described in: https://helda.helsinki.fi/handle/10138/40816 with a copy at Zenodo.

Correction of the errors was a confusing process and briefly described in: Hemilä H. Cochrane has not consistently followed the COPE guidelines. Eur J Clin Invest. 2020;50(4):e13216. https://doi.org/10.1111/eci.13216    https://hdl.handle.net/10138/326823