Tess Legg1, Silvy Peeters2, Phil Chamberlain2, Anna B Gilmore2. 1. Tobacco Control Research Group, Department for Health, University of Bath, Bath BA2 7AY, UK. Electronic address: t.legg@bath.ac.uk. 2. Tobacco Control Research Group, Department for Health, University of Bath, Bath BA2 7AY, UK.