Evaluating an audit and feedback intervention for reducing overuse of pathology test requesting by Australian general practitioners: protocol for a factorial cluster randomised controlled trial

INTRODUCTION: Consistent evidence shows pathology services are overused worldwide and that about one-third of testing is unnecessary. Audit and feedback (AF) is effective for improving care but few trials evaluating AF to reduce pathology test requesting in primary care have been conducted. The aim of this trial is to estimate the effectiveness of AF for reducing requests for commonly overused pathology test combinations by high-requesting Australian general practitioners (GPs) compared with no intervention control. A secondary aim is to evaluate which forms of AF are most effective. METHODS AND ANALYSIS: This is a factorial cluster randomised trial conducted in Australian general practice. It uses routinely collected Medicare Benefits Schedule data to identify the study population, apply eligibility criteria, generate the interventions and analyse outcomes. On 12 May 2022, all eligible GPs were simultaneously randomised to either no intervention control or to one of eight intervention groups. GPs allocated to an intervention group received individualised AF on their rate of requesting of pathology test combinations compared with their GP peers. Three separate elements of the AF intervention will be evaluated when outcome data become available on 11 August 2023: (1) invitation to participate in continuing professional development-accredited education on appropriate pathology requesting, (2) provision of cost information on pathology test combinations and (3) format of feedback. The primary outcome is the overall rate of requesting of any of the displayed combinations of pathology tests of GPs over 6 months following intervention delivery. With 3371 clusters, assuming no interaction and similar effects for each intervention, we anticipate over 95% power to detect a difference of 4.4 requests in the mean rate of pathology test combination requests between the control and intervention groups. ETHICS AND DISSEMINATION: Ethics approval was received from the Bond University Human Research Ethics Committee (#JH03507; approved 30 November 2021). The results of this study will be published in a peer-reviewed journal and presented at conferences. Reporting will adhere to Consolidated Standards of Reporting Trials. TRIAL REGISTRATION NUMBER: ACTRN12622000566730.