Could Low-Value Diagnostic Tests be Compounding Access Block? A Single-Site, Cross-Sectional Study

The study aimed to evaluate the prevalence and impact of low-value diagnostic tests at a regional, major-referral, mixed Emergency Department (ED).

A single-site, cross-sectional study was conducted at Townsville University Hospital in April 2022. Adult patients (aged 18 years and above) who underwent one of 10 specified diagnostic tests were included. The tests encompassed coagulation studies, urine cultures, blood cultures, cranial computed tomography (CT) in syncope, cranial CT in minor head injury, cervical spine CT in neck trauma, ankle X-ray in acute ankle trauma, duplex lower extremity ultrasound in suspected deep vein thrombosis, CT pulmonary angiography in suspected pulmonary embolism, and CT kidney ureter bladder in renal colic. Tests were classified as low-value based on Choosing Wisely recommendations, with their value determined by a research assistant using clinical documentation, prior to the availability of test results. Emergency clinicians were blinded to the study conduct.

Of all diagnostic tests performed, 48.2% (276/572) were deemed low-value, including 50.6% of laboratory tests (246/486) and 24.4% of imaging tests (21/86). The median ED length of stay was 6.1 h (IQR 3.9-8.5). Low-value imaging tests contributed to 152 lost bed-hours per 100 tests.

A substantial proportion of diagnostic tests were low-value, exacerbating access block and reducing the availability of ED beds, thereby delaying timely emergency care. The implementation of evidence-based, effective strategies is imperative to mitigate patient harm associated with low-value diagnostic tests.