Impact of the diagnostic label for a low-risk prostate lesion: protocol for two online factorial randomised experiments.

Many types of prostate cancer present minimal risk to a man's lifespan or well-being, but existing terminology makes it difficult for men to distinguish these from high-risk prostate cancers. This study aims to explore whether using an alternative label for low-risk prostate cancer influences management choice and anxiety levels among Australian men and their partners.

We will run two separate studies for Australian men and Australian women with a male partner. Both studies are between-subjects factorial (3×2) randomised online hypothetical experiments. Following consent, eligible participants will be randomised 1:1:1 to three labels: 'low-risk prostate cancer, Gleason Group 1', 'low-risk prostate neoplasm' or 'low-risk prostate lesion'. Participants will then undergo a second randomisation step with 1:1 allocation to the provision of detailed information on the benefits and harms of different management choices versus the provision of less detailed information about management choices. The required sample sizes are 1290 men and 1410 women. The primary outcome is the participant choice of their preferred management strategy: no immediate treatment (prostate-specific antigen (PSA)-based monitoring or active surveillance using PSA, MRI, biopsy with delayed treatment for disease progression) versus immediate treatment (prostatectomy or radiation therapy). Secondary outcomes include preferred management choice (from the four options listed above), diagnosis anxiety, management choice anxiety and management choice at a later time point (for participants who initially choose a monitoring strategy).

Ethics approval has been received from The University of Sydney Human Research Ethics Committee (2023/572). The results of the study will be published in a peer-reviewed medical journal and a plain language summary of the findings will be shared on the Wiser Healthcare publications page http://www.wiserhealthcare.org.au/category/publications/ TRIAL REGISTRATION NUMBERS: Australian New Zealand Clinical Trials Registry (ID 386701 and 386889).

BMJ open. 2024 Aug 09*** epublish ***

James Bullen, Brooke Nickel, Kirsten McCaffery, Timothy J Wilt, Jenna Smith, Farzaneh Boroumand, Lisa Parker, Jeremy Millar, John Brandt Brodersen, Philipp Dahm, Brett Delahunt, Murali Varma, Paul Glasziou, Andrew Warden, Lawrence Diller, Larry Billington, Christo van Rensburg, Katy Bell

School of Public Health, University of Sydney, Sydney, New South Wales, Australia., Sydney Health Literacy Lab, School of Public Health, University of Sydney, Sydney, New South Wales, Australia., Center for Chronic Disease Outcomes Research and Minneapolis VA High Value Care Initiative, Minneapolis VA Health Care System, Minneapolis, Minnesota, USA., School of Pharmacy, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia., Radiation Oncology, Alfred Health, Melbourne, Victoria, Australia., Centre of General Practice, Department of Public Health & Research Unit for General Practice, Region Zealand, University of Copenhagen, Copenhagen, Denmark., Department of Urology, University of Minnesota, Minneapolis, Minnesota, USA., Wellington School of Medicine and Health Sciences, University of Otago Wellington, Wellington, New Zealand., Department of Cellular Pathology, University Hospital of Wales, Cardiff, UK., Institute for Evidence-Based Healthcare, Bond University, Gold Coast, Queensland, Australia., Wiser Healthcare Research Collaboration, Sydney, New South Wales, Australia., Health Consumers New South Wales, Sydney, New South Wales, Australia., School of Public Health, University of Sydney, Sydney, New South Wales, Australia .