1. University of Auckland; School of Pharmacy; Private Bag 92019 Grafton Campus Auckland New Zealand
2. Barts & The London School of Medicine and Dentistry, Queen; UK Centre for Tobacco Control Studies, Wolfson Institute of Preventive Medicine; 55 Philpot Street Whitechapel London UK E1 2HJ
3. University of Auckland; Clinical Trials Research Unit; Private Bag 92019 Auckland New Zealand
4. University of Oxford; Department of Primary Health Care; Rosemary Rue Building Old Road Campus Oxford UK OX3 7LF