Evaluating Age-Adjusted D-dimer and Clinical Decision-Making in Suspected Pulmonary Embolism: A Retrospective Clinical Audit and Practitioner Survey
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background Pulmonary embolism (PE) is a common and potentially life-threatening condition encountered in acute medical practice. Computed tomography pulmonary angiography (CTPA) remains the standard imaging modality for diagnosis, but increasing utilisation raises concerns regarding radiation exposure, contrast-related complications, and healthcare resource use. This study evaluated diagnostic pathways for suspected PE through a retrospective clinical audit and practitioner surveys conducted before and after an educational intervention. Methods This study comprised a retrospective clinical audit of 1499 consecutive patients who underwent CTPA for suspected PE, an initial cross-sectional survey of 48 healthcare professionals, and a repeat cross-sectional survey of 33 healthcare professionals conducted after an educational intervention. Collected variables included demographics, Wells score, National Early Warning Score 2 (NEWS2), oxygen saturation, heart rate, D-dimer results, CTPA findings, alternative diagnoses, and in-hospital mortality. The practitioner surveys assessed knowledge of D-dimer testing, use of age-adjusted thresholds, and factors influencing clinical decision-making. Of 1499 CTPA episodes, 1150 had an interpretable D-dimer result. Eight episodes without a definitive CTPA reference-standard outcome were excluded, leaving 1142 episodes for the diagnostic-performance analysis. Results PE was confirmed in 206 of 1499 patients, giving an overall prevalence of 13.7%. Among 1142 episodes included in the diagnostic-performance analysis, the standard threshold demonstrated a sensitivity of 87.8% (95% CI 82.3%-91.7%) and specificity of 14.8% (95% CI 12.7%-17.2%). The age-adjusted threshold demonstrated a sensitivity of 86.2% (95% CI 80.5%-90.4%) and specificity of 23.4% (95% CI 20.8%-26.2%). False-positive classifications decreased from 813 to 731, an absolute reduction of 82 cases and a relative reduction of 10.1%, while false-negative classifications increased from 23 to 26. The initial practitioner survey identified important knowledge gaps. Age-adjusted D-dimer was used regularly by 21 (44%) of respondents and occasionally by 13 (27%), while six (12%) were unfamiliar with the concept. Following the educational intervention, regular use increased to 18 (54.5%), occasional use was reported by eight (24.2%), and unfamiliarity decreased to approximately one (3%). Awareness of the local D-dimer assay also improved. Clinical decision-making was influenced by fear of missing PE in 32/48 (66.7%) of respondents, while 24/48 (50.0%) reported that clinical impression could outweigh formal scoring systems. In the initial survey, 29/48 respondents (60.4%) were unsure which D-dimer assay was used locally. Conclusions Retrospective application of the age-adjusted threshold in this CTPA-selected cohort increased specificity and reduced false-positive classifications, with a small reduction in sensitivity and three additional false-negative classifications. Because the analysis was not restricted to patients with PE-unlikely or non-high pre-test probability and did not assess actual imaging utilisation or follow-up safety, these findings do not establish the safety of age-adjusted D-dimer as a PE rule-out strategy. The repeat practitioner survey demonstrated higher assay knowledge and self-reported use; however, causality cannot be inferred from the unpaired survey design.
Source: Cureus
Institution: Queen Elizabeth Hospital Birmingham
Language: English
Subfield: Internal Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7218946438