The Magnitude of Redundant Pathology Testing in Hospital Patients: A Multicentre Retrospective Observational Study

Abstract Background Redundant pathology testing is a significant quality issue in healthcare with the capacity to lead to unnecessary costs, resource strain, environmental waste and potential patient harm. This study aimed to assess the prevalence of potentially unnecessary repeat Full Blood Count (FBC), Electrolytes Urea Creatinine (EUC), and Calcium Magnesium Phosphate (CMP) testing within 24 hours in New South Wales (NSW) hospitals and to identify associated demographic and clinical factors. Methods A multicentre retrospective observational study was conducted across eight public hospitals in two NSW local health districts Australia, from January 2020 to December 2021. Data from the Laboratory Information System (LIS), Emergency Department Data collection (EDDC) and Admitted Patient Data Collection (APDC) were used. Chi-square statistics and multivariable logistic regression were used to identify factors associated with redundant testing. Results Of the total patient cohort, 35% had a repeat FBC, 33% had a repeat CMP, and 35% had a repeat EUC test <24 hours. Younger patients (<18 years) had higher odds of a repeat test < 24 hours compared to older age groups. Significant variability was observed across hospitals, with Hospitals C, D, and G exhibiting higher odds of repeat testing. Patients with ED encounters had higher odds of repeat tests compared to inpatient settings. Additionally, higher socioeconomic status was associated with increased repeat testing. Conclusions Our study revealed that there is a substantial prevalence of potentially unnecessary repeat pathology testing in NSW hospitals, with variations across demographic, institutional, and clinical factors. These findings highlight the need for targeted interventions to optimise test ordering practices.