The rule lets family doctors diagnose gout without drawing fluid from the joint. In the original study, 2.2% of low-score patients, 31% of intermediate and 80% of high-score patients had crystal-proven gout. Joint aspiration is still recommended when the score is intermediate.
How to use the Gout Diagnosis Calculator
- Male sex
- Previous attack of arthritis reported by the patient
- Onset within 1 day
- Joint redness
- Big toe (first MTP joint) involved
- Hypertension or at least one cardiovascular disease
- Serum uric acid above 5.88 mg/dL (350 µmol/L)
Results update as you type, and every field accepts the units shown in its menu.
How it works
Answer each question about the painful joint. The calculator adds the points and gives the probability band from the validation study.
Tips
- Use results from the same fasting state the formula expects (most lipid formulas assume fasting).
- Check the units on your lab report before entering values.
- Discuss treatment targets with your clinician – they depend on your overall risk.
- Repeat abnormal results; a single value can be misleading.
Common mistakes to avoid
- Using Friedewald LDL when triglycerides are above 400 mg/dL.
- Mixing mg/dL and mmol/L values in one calculation.
- Ignoring other risk factors such as smoking and blood pressure.
Inputs explained
| Field | What to enter |
|---|---|
| Male sex | Choose one: No, Yes |
| Previous attack of arthritis reported by the patient | Choose one: No, Yes |
| Onset within 1 day | Choose one: No, Yes |
| Joint redness | Choose one: No, Yes |
| Big toe (first MTP joint) involved | Choose one: No, Yes |
| Hypertension or at least one cardiovascular disease | Choose one: No, Yes |
| Serum uric acid above 5.88 mg/dL (350 µmol/L) | Choose one: No, Yes |
Health note: this calculator is for education and screening only and is not a diagnosis or treatment advice. Discuss your results with a qualified clinician.
Formula
Score: male 2 · previous patient-reported arthritis attack 2 · onset within 1 day 0.5 · joint redness 1 · first MTP joint (big toe) 2.5 · hypertension or cardiovascular disease 1.5 · serum uric acid > 5.88 mg/dL 3.5
≤ 4 low · 4.5–7.5 intermediate · ≥ 8 high probability
Worked example
Inputs — Male sex: Yes; Previous attack of arthritis reported by the patient: Yes; Onset within 1 day: Yes; Joint redness: Yes; Big toe (first MTP joint) involved: Yes; Hypertension or at least one cardiovascular disease: No; Serum uric acid above 5.88 mg/dL (350 µmol/L): Yes.
Results — Gout score = 11.5 / 13; Probability of gout = High (about 80%).
Key terms
- MTP
- Metatarsophalangeal joint at the base of the big toe.
Frequently asked questions
Can gout be diagnosed without a joint tap?
Often, using clinical rules like this; aspiration confirms it when unsure.
Why is uric acid only one part?
Uric acid can be normal during an attack and high in people without gout.
What should I do during an attack?
See a doctor for anti-inflammatory treatment; rest and ice the joint.