A cluster randomized trial to evaluate the effects of a quality cluster-based intervention on the use of prostate-specific antigen test in general practice—a study protocol

BACKGROUND: Continuous quality improvement is an important endeavor for keeping clinical practice up to date with research evidence and professional guidelines for the sake of patients and the rational use of system resources. Quality clusters are a framework for quality improvement in general practice, but the effects of working in quality clusters have not been evaluated in randomized trials. The use of prostate-specific antigen (PSA) tests in general practice represents a clinically relevant area for quality improvement due to recent guideline revisions, practice variation, and concerns about overuse. The objective of this study is to evaluate the effectiveness of a quality cluster-based intervention on the use of PSA tests in general practice. METHODS: The study is a cluster randomized controlled trial with an intervention group and a control group-receiving the intervention delayed-based in quality clusters in Denmark. We aim to include 50 quality clusters, each quality cluster having on average 13 general practice clinics. The intervention period is six months, and the total study period is 12 months. Randomization is 1:1 to intervention and control by a computer algorithm stratified by the five Danish health regions and cluster size. The intervention includes a cluster package about prostate-specific antigen used at a quality cluster meeting with data on use of prostate-specific antigen-tests, information on clinical guidelines, videos with clinicians, reflection questions, and hand-out materials to support implementation of changes to clinical practice. The control group proceeds with cluster work as usual and will receive the intervention delayed. Data for the primary and secondary outcomes will be obtained through registries and will be assessed at the end of the trial. DISCUSSION: We anticipate that the intervention will encourage general practitioners to reflect on their use of PSA testing and adjust their practice in accordance with the clinical guidelines if needed, and that this will result in an overall reduction in the use of the test. TRIAL REGISTRATION: Clinicaltrials.gov NCT06748456. Registered on 16.10.2024. https://clinicaltrials.gov/study/NCT06748456?id=NCT06748456&rank=1. Retrospectively registered.