Administration of antibiotics before incising the skin (‘surgical antimicrobial prophylaxis’) is a critical infection prevention strategy in surgery. Extending doses of prophylaxis into the postoperative period is a common practice in cardiac surgery; however, the benefit has not been clearly established and may lead to emergence of antimicrobial resistance and patient harm. We present the protocol for a large international multicentre, adaptive, pragmatic, double-blind, three-arm, placebo-controlled, randomised, non-inferiority clinical trial to compare the incidence of surgical site infection after three different durations of postoperative surgical antimicrobial prophylaxis in patients undergoing cardiac surgery.

This adaptive, multi-arm multistage non-inferiority trial will compare intraoperative only (Arm A), to intraoperative and 24 hours (Arm B) and, to intraoperative and 48 hours (Arm C) of intravenous cefazolin and placebo as surgical antimicrobial prophylaxis in 9180 patients undergoing cardiac surgery. The adaptive design allows for potential dropping of any of the three arms if clear inferiority is indicated at any of the scheduled interim analyses. The trial will evaluate the clinical and cost-effectiveness of the three different antibiotic prophylaxis durations.

Ethics approval will be obtained at all participating sites. Results of the study will be submitted for publication in peer-reviewed journals and the key findings presented at national and international conferences. Patients and members of the public will also be involved in the dissemination and translation of the trial results.

NCT05447559.

Most older adults living in residential aged care facilities (RACFs) have at least one marker of potentially suboptimal prescribing. Pharmacists play a crucial role in medication management, with their effectiveness enhanced by using computerised decision support tools. The Pharmacists Review to Optimise Medicines in Residential Aged Care (PROMPT-RC) study aims to optimise medicine use by providing pharmacists in RACFs with an electronic medicine management app with integrated decision support (AusTAPER App/Pathway) to use as part of medication reviews they undertake.

The PROMPT-RC study is a parallel cluster randomised controlled trial design involving Australian RACFs. It will assess if pharmacists’ use of the AusTAPER App/Pathway for medication reviews improves medication regimens for RACF residents compared with usual care. Pharmacists in RACFs randomised to the intervention arm will be trained to use the AusTAPER App/Pathway, which flags potentially inappropriate medicines (PIMs) across a person’s entire medicine regimen. Pharmacists in RACFs randomised to the control arm will not have access to the AusTAPER App/Pathway—they will continue to provide usual care. The primary outcome is the difference in the number of regular medicines between treatment arms at 12 months. Secondary outcomes will measure the number of regular and pro re nata medicines, PIMs, medicine administration times, medicine regimen complexity, use of antipsychotics, antidepressants, and benzodiazepines, quality of life, mortality, instances of physical restraint, and the number of falls, hospitalisations and general practitioner/health professional visits. The cost-effectiveness of the AusTAPER App/Pathway compared with usual care will be calculated. Data collection will occur at baseline, 3, 6, 9 and 12 months postrandomisation and 3 and 6 months prebaseline. We aim to recruit 668 participants to adjust for an estimated 10% loss to follow-up, giving 334 participants in each arm. Data analysis will follow an intention-to-treat approach using a linear mixed model.

Ethical approval was obtained from The University of Western Australia Human Research Ethics Committee (Reference: 2024/ET000525; approved 14 August 2024). Reciprocal approval was also obtained in other states. This study is registered on the Australian New Zealand Clinical Trials Registry (https://anzctr.org.au). Trial findings will be disseminated through national and international peer-reviewed publications and conferences.

ACTRN12624001409561.