Date	Event	Description
7 August 2008	New search has been performed	New literature search run. One new study identified: this did not change the conclusions of the review.
26 April 2008	Amended	Converted to new review format.
11 March 2003	New citation required and conclusions have changed	Five new studies were identified for the 2003 update of this review (Biernacki 1998; Joos 2000; Malmstrom 2002; Medici 2002; Shapira 2002). One study previously included was deemed not to have met the inclusion criteria for the review as it was carried out in COPD patients. The Description of studies, Methodological Quality of Included Studies, Results and Discussion sections were substantially revised, to reflect the need for more focused clinical trials. Following the inclusion of these studies data could be pooled for two outcomes (lung function and improvement in well‐being). These did not alter the conclusions of the review.