🫁 Wells Score Risk Stratification Simulator

Suspected Pulmonary Embolism at the Bedside

A brief placeholder lead on PE presentation and why risk stratification matters.

• ~1–2/1000: Annual PE incidence (placeholder population rate)
• ~30%: Untreated mortality (placeholder historical estimate)
• 2–3: Common symptoms (dyspnea, pleuritic pain, tachycardia)
• 1998–2000: Wells published (placeholder derivation years)

Why pretest probability comes first

Placeholder: symptoms are nonspecific, so structured scoring guides testing.

Placeholder: avoids over-testing low-risk patients and under-testing high-risk ones.

Assessing the Wells Criteria Checklist

Placeholder lead describing each of the seven weighted clinical criteria.

• 7: Total criteria (placeholder count)
• 12.5: Max possible score (placeholder ceiling)
• 3 pts: Highest weight item (DVT signs or PE most likely)
• 1 pt: Lowest weight item (hemoptysis or malignancy)

Criterion weighting rationale

Placeholder: each criterion weighted by its historical association with confirmed PE.

Placeholder: subjective item (alternative diagnosis) carries highest weight.

Summing Points into a Continuous Wells Score

Placeholder lead on how checked criteria sum into a single numeric score.

• 0–12.5: Score range (placeholder scale)
• Live: Update speed (recomputed on every toggle)
• 0.5 pt: Rounding (placeholder granularity)
• 2: Models supported (three-tier and two-tier)

From checklist to gauge

Placeholder: gauge needle position reflects current summed score.

Placeholder: thresholds vary by chosen scoring model.

Mapping Score to Pretest Probability Tier

Placeholder lead on low/moderate/high versus PE-likely/unlikely tiers.

• <2 pts: Three-tier low (placeholder cutoff)
• >6 pts: Three-tier high (placeholder cutoff)
• 4 pts: Two-tier cutoff (unlikely vs likely)
• ~67%: High-tier prevalence (placeholder PE rate)

Three-tier vs two-tier models

Placeholder: three-tier offers finer stratification.

Placeholder: two-tier simplifies decisions for D-dimer use.

Routing to D-Dimer or Direct CT Angiography

Placeholder lead on the branching pathway triggered by risk category.

• D-dimer: Low-risk pathway (placeholder rule-out step)
• Direct CTPA: High-risk pathway (placeholder confirmatory step)
• ~95%: D-dimer sensitivity (placeholder assay figure)
• ~96%: CTPA specificity (placeholder imaging figure)

Why the pathway branches

Placeholder: D-dimer safely excludes PE in low-probability patients.

Placeholder: high-probability patients skip straight to imaging.

Placeholder key insight: score-driven pathway reduces unnecessary CT scans.