see also [[Pulmonary Embolism]] , [[Statistics and research methods overview#Likelihood ratio nomogram (Fagan)|liklelihood ratios for VTE]], [[Pregnancy-Adapted YEARS algorithm]] > note: a lot of this is duplicated in the [[D-dimer]] article **advantages** - improve accuracy of non-invasive testing when combined with clinical pre-test probability and a sensitive [[D-dimer]] - may reduce inappropriate use of CTPA in ED **disadvantages** - certain criteria (age, malignancy, past PE/DVT) persist over time - may contribute to persistent high risk scores and unnecessary repeated investigation - *HR > 100* is only present in about 40% of patients, so is *not a sensitive criteria* for diagnosis | score | advantages | disadvantages | | ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------- | | Simplified Wells | - useful in identifying ↓ risk pts<br>- D dimer improves performance of score; low risk + -ve D dimer PE incidence ~ 0.5%<br>- most extensively validated prediction score <br>- easy to use<br>- info easily available | - loses objectivity because of how subjective "PE is as likely as or more likely than alternative Dx" | | Revised Geneva | - easily performed<br>- no subjective aspects to score; only uses clinical variables<br>- reported equivalent diagnostic performance with Wells | - less extensive validation than wells | # Scores ## Wells ![[D-dimer#Wells score]] ## Simplified Wells - everything just gets one point - high risk is > 1, low risk is ≤ 1 - DVT signs/symptoms - PE as likely ore more likely - HR > 100 - immobilisation - prior DVT - haemoptysis - malignancy ## Revised Geneva and simplified Geneva - low risk: <4 points original (≤ 2 simplified) ; PE incidence 8% - intermediate: 4-10 ; 28% - high risk: >10 (>2 simplified); 74% incidence > I'd never heard of "simplified Geneva" until I was taking notes on it; seems relatively unhelpful | variable | points <br>original | points <br>simplified | | ------------------------------------------------ | ------------------- | --------------------- | | Age > 65 | 1 | 1 | | prior DVT or PE | 3 | 1 | | surg or lower limb fracture <br>within one month | 2 | 1 | | active malignancy | 2 | 1 | | unilateral lower limb pain | 3 | 1 | | haemoptysis | 2 | 1 | | HR 75-94 | 3 | 1 | | HR > 95 | 5 | 2 | | pain on leg palpation and<br>unilateral oedema | 4 | 1 | ## PERC ![[D-dimer#PERC]] - parameters at original ED assessment ## YEARS 3 years items: **DGH** - **D**VT on exam - **G**estalt: is PE most likely Dx? - **H**aemoptysis any years items: D dimer set at 0.5 no years items: D dimer set at 1000 ## Pregnancy-adapted YEARS ![[Pasted image 20240321223931.png]]