Computer algorithm compared with routine clinical practice in screening for deep venous thrombosis in the leg in an emergency department

Objective: To audit routine clinical practice in screening patients admitted to an accident and emergency department for deep venous thrombosis in the leg (DVT) and compare it with a computer algorithm.

Design: Retrospective study of case notes with data subsequently entered into a computer algorithm followed by a comparison of the diagnosis and recommended management from each modality.

Setting: Emergency department at a London teaching hospital.

Population or sample: A convenience sample of 43 patients attending the emergency department.

Methods: Evaluation of clinical notes for completeness of assessment and correct diagnosis; entry of the same data into the computer algorithm.

Main outcome measures: Completeness of data collection, diagnosis of presence or absence of DVT, and recommended therapy.

Results: The Wells score was missing in the clinical evaluation in 60% of cases. Clinicians relied primarily on the results of ultrasound scans and in six cases the absence of required D-Dimer measurements meant that the algorithm stalled. Clinical and algorithm analysis and recommendations were not compliant in 10 cases (23%).

Conclusions: Clinical assessment of potential DVT in the accident and emergency department is poorly performed when compared with a computerised algorithm. Clinicians rely heavily on scan reports rather than clinical assessment which may have cost implications.