Mark J Hancock1
, Christopher G Maher1
, Jane Latimer1
, Andrew J McLachlan2
, Chris W Cooper3
, Richard O Day4
, Megan F Spindler1
and James H McAuley1 
1Back Pain Research Group, University of Sydney, PO Box 170, Lidcombe, NSW, 1825, Australia
2Faculty of Pharmacy, University of Sydney, NSW, 2006, Australia
3Discipline of General Practice, Balmain Hospital, 37A Booth St, Balmain, 2041, NSW, Australia
4Clinical Pharmacology, UNSW & St Vincent's Hospital, Darlinghurst 2010, NSW, Australia