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Introduction: This observational study conducted across seven emergency care units compares the efficacy of four D‐dimer detection methods, namely HemosIL D‐dimer HS (HS), HemosIL D‐dimer HS‐500 (HS‐500), VIDAS D‐dimer (VIDAS), and HemosIL AcuStar D‐dimer (ACUSTAR). The primary focus is on patients with a clinical suspicion of deep venous thrombosis (DVT) or pulmonary embolism (PE). Methods: A total of 149 samples were collected from patients with suspected DVT or PE. The confirmation of DVT/PE was based on calf ultrasound or computed tomography‐Angiography. Direct comparisons were made between the different detection methods, considering both their analytical performance and clinical utility. Additionally, the impact of an age‐adjusted cut‐off on the diagnostic accuracy of each method was assessed. Results: The results revealed comparable negative predictive value, sensitivity, and specificity across the methods, with a notable exception of increased specificity for HS compared with HS‐500 (50.8% vs. 41.5%, p = 0.03). Further analysis incorporating an age‐adjusted cut‐off demonstrated a significant improvement in specificity for HS. When using the age‐adjusted cut‐off, HS exhibited a substantial increase in specificity compared with HS‐500 (63.1% vs. 49.2%, p = 0.004) and demonstrated significantly higher specificity compared with VIDAS (63.1% vs. 53.8%, p = 0.04). Conclusion: The study emphasizes the nonuniversal effect of an age‐adjusted cut‐off and discusses the potential necessity for different cut‐off values, particularly in the case of HS‐500. These findings contribute to the understanding of D‐dimer detection methods in the context of DVT and PE, providing insights into their relative performances and the potential optimization through age‐adjusted cut‐offs. [ABSTRACT FROM AUTHOR]

Background: Phospholipid-dependent coagulation tests for lupus anticoagulant (LA) are considered an important step for the diagnosis of anti-phospholipid syndrome; however, LA laboratory detection is difficult because of many variables. Five hospital laboratories, located in a North-Italy area and using the same method for LA testing, cooperated to standardise sample treatment and analytical procedure in order to define the upper values for LA negativity. Methods: In total, 200 normal subjects (40 for each centre) were studied for six LA functional assays, using the same procedure, reagent lot and analyser type. The first tests done were LA screen and LA confirm assays, based on diluted Russell's Viper Venom Time, with low and high phospholipid content, respectively. The second tests performed were silica clotting time screen and confirm assays, based on activated partial thromboplastin time, with low and high phospholipid content, respectively. Finally, two mixing assays were executed for both screening assays, diluting patient sample with a pool prepared with plasma collected from the study population. Results: Data analysis demonstrated a difference between centres for all assays when results were expressed in seconds; the difference disappeared when results are normalised with the local mean normal value of each centre and are expressed as a normalised ratio. The study population was normally distributed; so the value corresponding to 99th percentile was used as limit value for LA negativity. Values expressed as normalised ratio, for LA and silica clotting time screenings were 1.22 and 1.23, respectively. Conclusions: The study allowed us to define a uniform approach to LA testing and evaluation for laboratories employing the same methods. [ABSTRACT FROM AUTHOR]