Differences in contributing factors to diagnostic errors between physicians and allied health professionals: a nationwide analysis in Japan

Abstract

Introduction Diagnostic errors significantly contribute to adverse events, patient harm and malpractice claims. While most research focuses on physicians, allied health professionals (AHPs) also play a critical role in diagnostic processes. Existing studies, primarily based on medical-record reviews, often overlook communication gaps and team dynamics affecting diagnostic accuracy. This study aims to (1) describe the overall characteristics and patterns of diagnostic errors reported in the national adverse-event database and (2) compare the clinical features, diagnostic processes and contributing factors between cases involving physicians and those involving AHPs. Methods We examined diagnostic-error reports from 1631 hospitals in the Japan Council for Quality Healthcare database (2010–2023). Cases were identified using predefined keywords, and two independent physicians assessed them using the Revised Safer Dx Instrument and Diagnostic Error Evaluation and Research (DEER) taxonomy. Contributing factors were analysed, and statistical methods explored error patterns and stakeholder comparisons. Results Among 147654 event reports, 445 cases involved diagnostic errors. The most common errors occurred in diagnostic testing, assessment and follow-up, particularly misinterpretation of pathological or radiological reports on new injuries during hospitalisation. Physicians were the primary responsible providers (79.3%), while nurses were involved in 19.3% of cases. DEER taxonomy analysis revealed that nurses were more associated with errors in presentation, history-taking and physical examination (p<0.001). Additionally, patient-related factors, observation, reporting and training played a significantly greater role in errors involving nurses than physicians (p<0.001). Discussion By leveraging expert-assessed unstructured data, this study provides a broader perspective on diagnostic safety. Findings highlight the critical role of AHPs in diagnostic errors. Our study underscores the need for targeted, profession-specific interventions embedded within broader interprofessional initiatives to effectively reduce diagnostic errors and enhance patient safety.