Date	Event	Description
13 March 2014	New citation required but conclusions have not changed	Text updated with new references. No new studies added, hence conclusions remain the same.
13 March 2014	New search has been performed	A search of the Cystic Fibrosis & Genetic Disorders Group's Cystic Fibrosis Trials Register did not identify any new studies potentially eligible for inclusion in this review.
15 February 2012	New citation required but conclusions have not changed	One of the new references identified was the full paper publication of a study previously identified as an e‐publication ahead of print and included (Chapman 2009). The other study (two references) has been included in this update (Haworth 2011). A study previously listed as 'Awaiting classification' has also now been included (Papaioannou 2008).
15 February 2012	New search has been performed	A search of the Group's Cystic Fibrosis Trials Register identified three new references to two separate studies.
26 April 2010	Amended	Contact details updated.
18 July 2009	New citation required and conclusions have changed	A new review team has updated the review. As part of this update the sections 'Methods' and 'Risk of Bias in included studies' have been substantively revised and updated.
18 July 2009	New search has been performed	A search of the Group's Cystic Fibrosis Trials Register was run in October 2008. Five references to four new trials were identified; two trials have been included (Aris 2004; Chapman 2009) and two trials have been excluded (Conway 2004; Hardin 2005). One newly identified trial has been listed as 'Awaiting classification' until the authors have been able to contact the trial investigators (Papaioannou 2008a).
10 November 2004	New search has been performed	A search of the Group's Cystic Fibrosis Trials Register was run in August 2004, but no new references were identified.
12 November 2003	New search has been performed	The searches identified no new studies to be included in the review. Minor style changes have been made.
13 November 2002	New search has been performed	An additional reference [abstract] to the Haworth 2001 trial has been incorporated into the review.
20 August 2001	New citation required and conclusions have changed	Substantive amendment