Nasir Warfa*, Sarah Curtis, Charles Watters, Ken Carswell, David Ingleby and Kamaldeep Bhui*
* Corresponding authors: Nasir Warfa n.warfa@qmul.ac.uk - Kamaldeep Bhui k.s.bhui@qmul.ac.uk
BMC Public Health 2012, 12:749 doi:10.1186/1471-2458-12-749