Overuse of imaging for pulmonary embolism in emergency departments: a systematic review and meta-analysis

Pulmonary embolism (PE) is a life-threatening condition whose diagnosis can be challenging. Despite clinical decision rules (CDRs) like the PERC rule and Wells’ score, concerns over missed diagnoses contribute to the overuse of computed tomography angiography (CTA) and ventilation/perfusion (V/Q) scans. This study estimates the proportion of potentially avoidable imaging performed in emergency departments (EDs) for adult patients with suspected PE. A systematic search was conducted in MEDLINE (OVID), CINAHL (EBSCO), Embase.com, CochraneLibrary.com, and Web of Science Core Collection (8 indexes), complemented by manual searches from inception to July 2025. Studies were included if they reported the proportion of CTA or V/Q scans performed despite a CDR not recommending imaging. Two independent reviewers selected the articles and extracted the data; a third reviewer resolved any disagreements. Study quality was assessed using QUADAS-2, and a meta-analysis was performed with a random-effects model, including subgroup and sensitivity analyses based on continents, CDR type, and whether the subjective component of the CDR was assessed by the treating physician. Thirty-four studies were included. The pooled proportion (95% confidence interval) of potentially avoidable imaging was estimated at 22% (17–28), with high heterogeneity (I² = 99.4%). Across CDRs supported by the current literature, the PERC rule yielded the lowest pooled proportion (10% [7–14]), while the YEARS criteria had the highest (42% [11–81]). Sensitivity analyses restricted to studies with low risk of bias (n = 7) and low applicability concerns (n = 15) showed slightly higher pooled proportions of potentially avoidable imaging (27% and 28%, respectively). Optimizing CDR adherence in EDs could substantially reduce unnecessary imaging for PE, lowering costs and minimizing environmental impact. This review highlights the benefits of stricter CDR implementation in routine PE assessment.