The impact of a social norms approach on reducing levels of misperceptions around smokefree hospital entrances amongst patients, staff, and visitors of a NHS hospital: a repeated cross-sectional survey study.

People hold misperceptions of the proportion of people who choose to smoke in the hospital entrance. The social norms approach campaign was associated with a strengthening of positive social norms. Such campaigns should be considered by Trusts as one evidence-based based tactic to denormalise smoking, increase support for smokefree policies.