From the Guidelines
The Wells score for pulmonary embolism (PE) is used to assess the clinical probability of PE in patients with suspected symptoms, helping clinicians determine which patients should undergo further diagnostic testing. This validated clinical prediction rule stratifies patients into low, moderate, or high risk categories based on clinical features such as hemoptysis, history of DVT or PE, immobilization, tachycardia, and whether PE is the most likely diagnosis 1. The Wells score is a crucial tool in emergency settings, where rapid clinical decision-making is essential for proper resource allocation and patient management.
Key Points
- The Wells score improves diagnostic efficiency by reducing unnecessary testing in low-risk patients while ensuring appropriate evaluation of higher-risk individuals.
- For patients with low Wells scores, PE can often be safely ruled out with a negative D-dimer test, avoiding unnecessary imaging 1.
- Those with moderate or high scores typically require diagnostic imaging such as CT pulmonary angiography.
- The false-negative rate of CT pulmonary angiogram alone in patients clinically deemed high risk for PE ranges in studies from 5.3% to 40%, highlighting the need for additional testing in high-risk patients 1.
Clinical Application
The Wells score is a valuable tool in clinical practice, allowing clinicians to quickly and accurately assess the likelihood of PE in patients with suspected symptoms. By stratifying patients into low, moderate, or high risk categories, clinicians can make informed decisions about further diagnostic testing and treatment.
Evidence-Based Recommendation
The Wells score should be used in conjunction with clinical judgment and other diagnostic tests, such as D-dimer and CT pulmonary angiography, to diagnose and manage PE. This approach ensures that patients receive appropriate and timely treatment, while also reducing unnecessary testing and minimizing the risk of false-negative or false-positive results 1.
From the Research
Overview of the Wells Score
The Wells score is a clinical decision rule used to assess the pretest probability of pulmonary embolism (PE) in patients suspected of having the condition 2, 3, 4, 5, 6.
Purpose of the Wells Score
The primary purpose of the Wells score is to help clinicians determine the likelihood of PE in a patient, which can guide further diagnostic testing and treatment decisions 2, 3, 4, 5, 6.
Key Features of the Wells Score
Some key features of the Wells score include:
- It is a widely used and validated clinical decision rule for assessing pretest probability of PE 2, 3, 4, 5, 6
- It has been compared to other clinical decision rules, such as the simplified revised Geneva score and the British Thoracic Society score, and has been found to have good predictive accuracy 2, 6
- It can be used in combination with D-dimer testing to safely rule out PE in patients with low to moderate pretest probability 3, 4, 5
- It has been simplified and validated in various studies, with a simplified version showing similar diagnostic performance to the original rule 5
Clinical Applications of the Wells Score
The Wells score has several clinical applications, including:
- Assessing pretest probability of PE in patients suspected of having the condition 2, 3, 4, 5, 6
- Guiding further diagnostic testing, such as D-dimer testing or imaging studies 3, 4, 5
- Identifying patients at low risk of PE who may not require further testing or treatment 4, 5
- Identifying patients at high risk of PE who may require urgent treatment or further evaluation 2, 3, 6