Pulmonary embolism (PE) is a blockage of one of the arteries in the lung, frequently caused by a blood clot that has travelled to the lung from another part of the body. If left untreated, it can be fatal in up to 30% of patients. Computed tomography (CT) is the most commonly used imaging modality to diagnose PE. CT is associated with radiation exposure, and as such there is concern with its overuse. Once diagnosed, the main treatment for PE is anticoagulant therapy.
It is a challenge to diagnose PE. And, there is controversy among experts as to the optimal diagnostic strategy for suspected PE. Although common symptoms include shortness of breath, chest pain, and cough, the clinical presentation of PE can vary greatly. A number of clinical assessment tools exist to help clinicians determine who requires further testing and imaging, but their use is inconsistent. Often a series of tests is ordered, which can be very costly and may result in either a missed diagnosis or an overdiagnosis. Because there are so many different clinical assessment tools, tests, and imaging modalities — each with separate technical additions that can enhance its performance — the appropriate clinical decision, rules, and imaging modalities to assess PE remain uncertain.
To address this challenge, CADTH undertook an Optimal Use project to assess the diagnostic test accuracy, clinical and cost-effectiveness, and safety of clinical decision rules and imaging modalities for acute PE in patients in urban, rural, and remote settings. Patient-centered and implementation considerations, as well as potential environmental impact were also addressed.