Date	Event	Description
5 August 2013	New search has been performed	A search of the Group's CF Trials Register identified 23 new references which were potentially eligible for inclusion in the review; two of these studies were assessed as suitable for inclusion (Elkins 2005; Jarad 2010) and the remaining 21 were excluded.
5 August 2013	New citation required but conclusions have not changed	A new review team have taken on this review at this update. Despite the inclusion of two new studies in this updated review, the conclusions remain the same.
18 February 2009	Amended	The Methods section has been updated in light of new guidance and functionality of RevMan 5.
18 February 2009	New search has been performed	A search of the Group's Cystic Fibrosis Trials Register identified one additional reference to an already included study (Braggion 1995) and one to an already excluded study (Tannenbaum 2001).
12 November 2008	Amended	Converted to new review format.
20 February 2008	Amended	The Plain Language Summary has been updated in line with guidance from The Cochrane Collaboration. Also, in a post hoc change and in line with Group guidelines, the outcome measures have been split into 'Primary outcomes' and 'Secondary outcomes'.
20 February 2008	New search has been performed	The search of the Group's Cystic Fibrosis Trials Register identified one new reference which was the main paper to a previously excluded abstract (Lagerkvist 2006).
14 November 2006	New search has been performed	The search of the Group's Cystic Fibrosis Trials Register identified two new references. Both studies were excluded (Stites 2006; Warwick 2004).
14 November 2005	New search has been performed	The search of the Group's Cystic Fibrosis Trials Register identified four new references. One study identified was not eligible for inclusion in the review and has been added to the 'Excluded studies' section (Chatham 2004). The remaining three references were to three already excluded studies (Darbee 1990; Marks 1999; McIlwaine 1997).
18 May 2004	New search has been performed	Additional references (providing no additional information) have been added to the following already 'Included studies': Mortensen 1991; Falk 1993. Additional references have been added to the following already 'Excluded studies': Button 1997a; Costantini 1998; Orlik 2001. Three new studies have been added to 'Excluded studies': Hare 2002; Orlik 2000; Tannenbaum 2001.
14 August 2002	New search has been performed	Six crossover trials, previously cited in "Excluded Studies" have now been moved to the "Included Studies" section (Braggion 1995; Falk 1993; Mortensen 1991; Pfleger 1992; Rossman 1982; van der Schans 1991). Relevant changes to the text of the review have been made. Four new "Excluded Studies" have been incorporated into the review (Battistini 2001; Keller 2001; Pollard 2000; Orlick 2001). Additional references to studies already listed in "Excluded Studies" have been incorporated into the review within the following study ID's: Button 1997a; Gondor 1999; Grasso 2000; Marks 1999; Newhouse 1998).
9 February 2000	New citation required and conclusions have changed	Substantive amendment