A randomized controlled trial of the effectiveness of combinations of ‘why to reduce’ and ‘how to reduce’ alcohol harm-reduction communications

Abstract

Introduction: Alcohol is a major source of harm worldwide. The aim of this study was to experimentally assess the effects of exposing Australian adult drinkers to combinations of ‘why to reduce’ and ‘how to reduce’ alcohol harm-reduction messages. Methods: Three online surveys were administered over six weeks: Time 1 at baseline (n = 7,995), Time 2 at three weeks post-baseline (n = 4,588), and Time 3 at six weeks post-baseline (n = 2,687). Participants were randomly assigned to one of eight conditions: (1) a control condition; (2) a ‘why to reduce’ television advertisement; (3–5) one of three ‘how to reduce’ messages referring to the following protective behavioral strategies (PBSs): Keep co..