Date	Event	Description
26 February 2009	New search has been performed	One new included study (Karon 1981) bringing the total number of included trials to four. We also identified a further report of the May 1976 study and were able to extract additional outcome data.
10 December 2008	Amended	Converted to new review format.
24 May 2001	New citation required and conclusions have changed	Substantive amendment