The score is a weighted sum of seven clinical features from a validated diagnostic rule for acute monoarthritis. Points: Male (2.0), Previous attack (2.0), Onset within 1 day (1.0), Joint redness (1.5), First MTP involved (2.5), Hypertension/Cardiovascular disease (1.5), Serum urate > 5.88 mg/dL (3.5). Maximum score is 13.0.
Interpretation (commonly used): ≤ 4 low probability; 4.5–7.5 intermediate probability; ≥ 8 high probability. Joint aspiration and crystal analysis are recommended when probability is intermediate.
- Complete the fields based on the patient’s presentation and available labs.
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Paste CSV with columns: male,prev_attack,onset_1d,redness,mtp1,cvd,urate,urate_unit
| # | male | prev_attack | onset_1d | redness | mtp1 | cvd | urate | unit | score | tier |
|---|
| Variable | Value | Points |
|---|---|---|
| Male sex | - | 0 |
| Previous arthritis attack | - | 0 |
| Onset within one day | - | 0 |
| Joint redness | - | 0 |
| First MTP involvement | - | 0 |
| Hypertension/CV disease | - | 0 |
| Serum urate threshold | - | 0 |
| Total | 0.0 | |
| Sex | Prev attack | Onset <= 1d | Redness | First MTP | HTN/CVD | Urate | Score | Tier |
|---|---|---|---|---|---|---|---|---|
| Male | Yes | Yes | Yes | Yes | No | 7.2 mg/dL | 11.5 | High |
| Female | No | No | No | No | No | 4.8 mg/dL | 0.0 | Low |
Example rows are fictional and for demonstration only.
1) Clinical variables and weights
| Variable | Definition (used here) | Points |
|---|---|---|
| Male sex | Sex assigned male at birth | 2.0 |
| Previous attack | Prior episode of acute arthritis | 2.0 |
| Onset ≤ 1 day | Time to maximal pain within 24 hours | 1.0 |
| Redness | Erythema over affected joint | 1.5 |
| First MTP involved | Big toe joint affected | 2.5 |
| HTN/CV disease | Hypertension or cardiovascular disease present | 1.5 |
| Serum urate > 5.88 mg/dL | Threshold exceeded in any unit | 3.5 |
| Maximum score | 13.0 | |
2) Probability bands and typical actions
| Score band | Probability tier | Typical next steps |
|---|---|---|
| ≤ 4.0 | Low | Consider other causes of monoarthritis |
| 4.5 – 7.5 | Intermediate | Consider synovial fluid analysis for crystals |
| ≥ 8.0 | High | Gout likely; manage per local guidance |
3) Serum urate thresholds and conversions
| Threshold | mg/dL | mmol/L | µmol/L |
|---|---|---|---|
| Diagnostic rule cut-off | 5.88 | 0.36 | 360 |
| Common target (maintenance) | ≤ 6.0 | ≤ 0.36 | ≤ 360 |
| Stringent target (severe tophaceous) | < 5.0 | < 0.30 | < 300 |
4) Common differentials in acute monoarthritis
| Condition | Clue | Comment |
|---|---|---|
| Septic arthritis | Fever, severe pain, high CRP | Urgent evaluation to avoid joint damage |
| Calcium pyrophosphate disease | Chondrocalcinosis, older age | Rhomboid weakly positive birefringent crystals |
| Reactive arthritis | Post-infectious onset | Often asymmetric, large joints |
| Trauma/hemarthrosis | Injury history, anticoagulation | Consider imaging or aspiration |
These data are for education and quick reference alongside the calculator.
1) What does my total score mean?
Scores ≤4 suggest low probability; 4.5–7.5 suggest intermediate probability; ≥8 suggest high probability of gout. Always consider the whole clinical picture and local protocols when deciding testing or treatment strategies.
2) Can a normal uric acid level exclude gout?
No. Serum urate may be normal during an acute flare. The scoring rule uses a threshold, but joint aspiration and crystal analysis remain important when the probability is intermediate or diagnosis is uncertain.
3) When should synovial fluid be aspirated?
Consider aspiration when the score is intermediate, when septic arthritis is possible, when presentation is atypical, or when management hinges on confirmation. Crystal identification provides the most specific diagnostic evidence for gout.
4) How is this rule different from ACR/EULAR criteria?
This bedside rule is a simple primary-care aid using seven items. ACR/EULAR 2015 classification is broader and weighted, often requiring imaging or crystal evidence when available.
5) Do diuretics or tophi change the score?
No. They do not change the calculated score here. They are captured as annotations for context. Clinical judgment should incorporate such factors alongside the score when assessing likelihood and planning care.
6) How accurate is the score?
The rule was derived and validated in primary care cohorts and shows good discrimination. However, performance varies by population and setting. Use as supportive evidence rather than a standalone diagnostic decision.
- Janssens HJEM, et al. Diagnostic rule for acute gouty arthritis in primary care. 2010.
- Common interpretation thresholds: ≤4 low, 4.5–7.5 intermediate, ≥8 high.
- ACR/EULAR 2015 classification criteria emphasize crystal confirmation when feasible.