7 Validated Scores

Clinical Scoring Systems

Peer-reviewed, validated clinical scoring tools for emergency medicine, critical care, cardiology, and respiratory medicine. Every score includes interpretation thresholds, clinical decision support, and a reference to its original validation study.

Original validation papers Instant scoring Clinical decision support Printable PDF reports
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🧠
Glasgow Coma Scale (GCS)
Neurological assessment scoring eye opening, verbal, and motor responses. Includes severity classification, intubation threshold guidance, prognosis interpretation, and printable neurological observation chart.
Emergency Use tool
❤️‍🩹
Wells Score (DVT / PE)
Pre-test probability for deep vein thrombosis and pulmonary embolism in one tool. Includes D-dimer guidance, imaging recommendations per ACCP guidelines, and two-level vs three-level scoring options.
Emergency Use tool
🫀
CHA₂DS₂-VASc Score
Stroke risk stratification in non-valvular atrial fibrillation. Displays annual stroke risk percentage per score point, anticoagulation recommendations per ESC and ACC/AHA guidelines, and HAS-BLED bleed risk cross-reference.
Cardiology Use tool
📋
APACHE II Score
Acute Physiology and Chronic Health Evaluation II for ICU mortality prediction. 12 physiological variables plus age and chronic health points, with predicted hospital mortality percentage and risk stratification.
ICU / Critical Care Use tool
💓
TIMI Risk Score (UA/NSTEMI)
7-point risk score for unstable angina and NSTEMI. Predicts 14-day all-cause mortality and major ischaemic events with early invasive vs conservative management strategy guidance.
Cardiology Use tool
📉
QTc Interval Calculator
Corrected QT interval using Bazett, Fridericia, Framingham, and Hodges formulas simultaneously. Drug-induced QT prolongation risk classification with CredibleMeds reference and normal range table by age and sex.
Cardiology Use tool
🫁
CURB-65 Score
Pneumonia severity index for outpatient vs inpatient vs ICU admission decisions. Scores confusion, urea, respiratory rate, blood pressure, and age ≥65 with 30-day mortality risk and BTS guideline-based management pathway.
Respiratory Use tool
No scores match this filter.

Score Quick Reference

Interpretation thresholds at a glance — click any card to open the full scoring tool.

🧠 Glasgow Coma Scale
13–15Mild / Normal
9–12Moderate injury
≤ 8Severe — consider intubation
3Deep coma / brain death
Open GCS Calculator →
❤️ Wells Score (DVT)
≤ 1Low probability
2–6Moderate probability
≥ 7High probability
≤ 4PE unlikely (two-level)
Open Wells Score →
🫀 CHA₂DS₂-VASc (AF)
0 (M) / 1 (F)Low — no OAC needed
1 (M) / 2 (F)Consider OAC
≥ 2 (M) / ≥ 3 (F)OAC recommended
Max 9~15.2% annual stroke risk
Open CHA₂DS₂-VASc →
📋 APACHE II (ICU)
< 10~4% predicted mortality
10–19~9–15% mortality
20–29~20–40% mortality
≥ 30>50% predicted mortality
Open APACHE II →
💓 TIMI (UA/NSTEMI)
0–1~5% 14-day event rate
2–3~13% event rate
4–5~20% — consider early invasive
6–7~41% — high risk
Open TIMI Score →
🫁 CURB-65 (Pneumonia)
0–1Low risk — home treatment
2Moderate — consider admit
3–4Severe — admit
5Very severe — consider ICU
Open CURB-65 →
📖
Built from Original Papers
Every score is coded from its original validation study — not secondary summaries. Criteria, point values, and thresholds are cross-referenced against MDCalc, UpToDate, and the primary publication.
🩺
Decision Support Built In
A number alone isn't enough. Every score displays the management pathway that goes with it — imaging decisions, anticoagulation thresholds, admission criteria — aligned with current guidelines.
📄
Printable Clinical Reports
Generate a PDF report of any scoring session — including individual item responses, total score, interpretation, and recommended next steps — suitable for clinical notes or handover.
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About Clinical Scoring Systems

Clinical scoring systems transform complex, multi-variable patient data into a single standardised number that correlates with outcomes. Unlike calculators that apply a formula to raw inputs, validated scoring systems are derived from large patient cohort studies and have been prospectively tested against real-world outcomes — making them among the most powerful decision-support tools in evidence-based medicine.

How Scoring Systems Are Validated

A clinical score is only as good as its validation data. The Gold Standard process involves three stages: derivation (developing the score in a discovery cohort), internal validation (testing in a different portion of the same dataset), and external validation (testing in entirely different patient populations and settings). All scores on MediCalc Pro have undergone external validation and are in routine clinical use as recommended by major specialty societies.

Emergency Medicine Scores

The Glasgow Coma Scale remains the most widely used neurological assessment tool worldwide, used at scene, in the ED, and throughout ICU admission to track consciousness trends. The Wells Score for DVT and PE is embedded in most emergency department clinical pathways and, when combined with a D-dimer, can safely rule out thromboembolism without imaging in low-probability patients.

Cardiology Scores

The CHA₂DS₂-VASc Score is the standard tool for anticoagulation decision-making in atrial fibrillation, recommended by both ESC and ACC/AHA guidelines. The TIMI Risk Score stratifies UA/NSTEMI patients into management pathways, guiding the decision between early invasive (catheterisation within 24–48h) and conservative strategies. The QTc Calculator is essential for monitoring drug-induced QT prolongation — a preventable cause of fatal arrhythmia.

ICU and Critical Care

APACHE II is the most widely used severity-of-illness score in critical care globally, correlating strongly with ICU and hospital mortality. It is used for benchmarking ICU performance, communicating prognosis, and triaging ICU admission. Note that APACHE II should supplement — not replace — clinical judgement; individual patients may deviate significantly from population-level predictions.

Respiratory Medicine

CURB-65 is the BTS-recommended tool for community-acquired pneumonia severity assessment. It is fast to compute at the bedside (five criteria, each worth one point) and maps directly to a management pathway — low score patients can be safely treated at home, while high score patients warrant hospital or ICU admission.

Frequently Asked Questions

What is the Glasgow Coma Scale and how is it scored? +
The GCS assesses level of consciousness across three domains: eye opening (E, scored 1–4), verbal response (V, scored 1–5), and motor response (M, scored 1–6). The total score (3–15) is expressed as E+V+M. A score of 13–15 indicates mild impairment, 9–12 moderate, and 8 or below severe brain injury — the threshold commonly used to define coma and guide intubation decisions.
How do I use the Wells Score to rule out PE? +
Using the two-level Wells Score: a score of 4 or below makes PE "unlikely." In these patients, a negative high-sensitivity D-dimer effectively rules out PE without the need for CT pulmonary angiography (CTPA). A score above 4 makes PE "likely" and CTPA is recommended regardless of D-dimer result. This pathway is endorsed by ACCP and NICE guidelines and reduces unnecessary radiation exposure and contrast use.
When should I anticoagulate based on CHA₂DS₂-VASc score? +
Per ESC 2020 guidelines: male patients with a score of 0, and female patients with a score of 1 (accounting for the female sex point), are at low stroke risk and anticoagulation can be withheld. Male patients with score ≥2 and female patients with score ≥3 have high stroke risk and oral anticoagulation (preferably a DOAC) is recommended. Intermediate scores (1 in males, 2 in females) require individual clinical judgement weighing stroke risk against bleeding risk.
Which QTc formula should I use — Bazett or Fridericia? +
The Bazett formula (QTc = QT ÷ √RR) is most commonly cited in drug labels and clinical practice, but it overestimates QTc at high heart rates and underestimates it at slow rates. The Fridericia formula (QTc = QT ÷ ∛RR) is more accurate at extremes of heart rate and is preferred in research settings. Our QTc calculator shows all four major formulas simultaneously so you can see the range and choose the most appropriate for context.
Are these scoring tools validated for all patient populations? +
Each score has specific derivation and validation populations. The GCS, Wells Score, and CURB-65 have been extensively externally validated across diverse populations. APACHE II performs less well in specific subgroups (burns, post-cardiac surgery). CHA₂DS₂-VASc was derived primarily in European AF cohorts. All scores should be applied with awareness of their original validation context. Our tool pages include notes on known limitations for each score.

Related Tools on MediCalc Pro

For 10-year cardiovascular disease risk, see the Framingham Risk Score. For anticoagulation dose calculation based on CHA₂DS₂-VASc result, see the Weight-Based Dose Calculator. For ICU fluid management alongside APACHE II, see the IV Drip Rate Calculator. For paediatric neurological assessment, see APGAR Score.

Key References

  • Teasdale G, Jennett B. "Assessment of coma and impaired consciousness." Lancet. 1974;2(7872):81-84.
  • Wells PS, et al. "Evaluation of D-dimer in the diagnosis of suspected deep-vein thrombosis." NEJM. 2003;349:1227-1235.
  • Lip GY, et al. "Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation." Chest. 2010;137(2):263-272.
  • Knaus WA, et al. "APACHE II: a severity of disease classification system." Critical Care Medicine. 1985;13(10):818-829.
  • Antman EM, et al. "The TIMI risk score for unstable angina/non-ST elevation MI." JAMA. 2000;284(7):835-842.
  • Lim WS, et al. "Defining community acquired pneumonia severity on presentation to hospital: an international derivation and validation study." Thorax. 2003;58(5):377-382.
⚠️ Medical Disclaimer: Clinical scoring tools are designed to support — not replace — clinical judgement. Scores must be interpreted in the context of the individual patient's complete clinical picture. Always consult current clinical guidelines and a qualified healthcare professional for all management decisions.
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