The impact of pictorial health warnings on tobacco products in smokers behaviours and knowledge: the first quasi-experimental field trial after the implementation of the tobacco law in Italy.

Background: The aim of the study was to evaluate in the Italian smokers, the effects of implementation of the law about Pictorial Health Warnings (PHWs) on tobacco products.

Methods: A quasi-experimental longitudinal design was conducted between 2016 and 2017. The data were collected before (pre-PHW/Wave 1) and after (post-PHW/Wave 2) the implementation of the law.