The Response of Smokers to Health Warnings on Packs in the United Kingdom and Norway Following the Introduction of Standardized Packaging.

Two longitudinal online surveys in the United Kingdom and Norway explored the impact of standardized packaging on warning salience and effectiveness. That warning salience and effectiveness only increased in the UK postimplementation, where standardized packaging was implemented alongside new larger pictorial warnings on the pack front and reverse, and not in Norway, where standardized packaging was introduced but older smaller text warnings (pack front) and pictorial warnings (pack reverse) were retained, highlights the importance of removing full branding and introducing stronger warnings simultaneously.