Diagnostic errors in primary care are common, particularly in the interpretation and follow-up of abnormal haemoglobin (Hgb) and estimated glomerular filtration rate (eGFR) results. These errors frequently result in missed or delayed diagnoses of serious conditions such as anaemia and chronic kidney disease. This protocol describes a stepped-wedge cluster randomised controlled trial designed to evaluate a novel, evidence-based, team-based intervention aimed at improving diagnostic safety and efficiency.

The study will be conducted across 12 University of Texas Physicians (UTPs) primary care clinics in Houston, Texas, USA. Adult patients (≥18 years) with newly identified abnormal Hgb or eGFR results will be eligible for inclusion. The intervention integrates automated tracking of abnormal laboratory results, nurse navigators to support patient follow-up and engagement, and clinical pathologists to provide diagnostic guidance to primary care providers. The primary outcome is diagnostic safety, defined as the proportion of patients who receive a correct diagnosis within 6 months. Secondary outcomes include diagnostic efficiency, appropriate test utilisation, cost-effectiveness, patient activation and implementation metrics such as acceptability, fidelity and sustainability. The study will also explore barriers and facilitators to successful implementation using mixed-methods evaluation.

This trial has been approved by the Institutional Review Board at The University of Texas Health Science Center at Houston. Study results will be disseminated through peer-reviewed publications and conference presentations, and findings will be reported to UTP leadership to inform potential system-wide implementation.

NCT05735314.