Submitted on: 14 September 2002.
Revised on: 14 October 2002.
Accepted on: 27 October 2002.
___________________JAMA Health Forum---AMER MEDICAL ASSOC
Submitted on: 27 December 2007.
Revised on: 10 April 2008.
Accepted on: 19 May 2008.
___________________JAMA Health Forum---AMER MEDICAL ASSOC
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Submitted on: 29 January 2004.
Revised on: 11 March 2004.
Accepted on: 14 April 2004.
___________________JAMA Health Forum---AMER MEDICAL ASSOC
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