Smarter, Shorter, Safer: Study protocol for a stepped-wedge cluster randomised controlled trial and process evaluation of a behavioural intervention bundle to reduce antibiotic use in residential aged care

Introduction The overuse and prolonged use of antibiotics in residential aged care (RAC) increases the risk of adverse effects and contributes to the global threat of antimicrobial resistance. Behavioural science-informed interventions have effectively reduced antibiotic prescribing in primary care but have rarely been implemented in RAC settings. We co-developed a behavioural science intervention bundle named Smarter, Shorter, Safer with RAC providers. We aim to assess the effectiveness of the intervention on rates of antibiotic use, measure effect persistence 6-months after the final intervention round, and investigate stakeholder experiences of the intervention. Methods and analysis We will conduct a stepped-wedge cluster randomised controlled trial with an embedded qualitative process evaluation. RAC homes (n=46) will be stratified into tertiles of baseline antibiotic use and randomly allocated to three intervention roll-out steps. Each RAC home will receive a bundled intervention consisting of social norm feedback, public commitment messaging and consumer information, staggered by step. Three rounds of the intervention will be delivered to each home at quarterly intervals. The primary outcome is antibiotic days of therapy per 1000 resident days (DOT/1000 days). Secondary outcomes are the percentage of antibiotic courses with a duration longer than guidelines and the percentage of residents on an antibiotic. Qualitative interviews will investigate staff and consumer experiences of the intervention bundle over time and by high, median and low baseline antibiotic use rates. Ethics and dissemination We obtained ethical approval from the Macquarie University Human Research Ethics Committee. Our findings will be disseminated through a range of forums including the publication of results in peer-reviewed journals and presentations at national and international conferences. Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12625001132437 (https://anzctr.org.au/ACTRN12625001132437.aspx)