acute_gout_diagnosis: Acute Gout Diagnosis Rule (Janssens Rule)

In cliot: Clinical Indices and Outcomes Tools

Acute Gout Diagnosis Rule (Janssens Rule)

Description

Calculates the Acute Gout Diagnosis Rule score to estimate the probability of gout in primary care patients presenting with acute arthritis. This rule is particularly useful when synovial fluid analysis is not immediately available. It categorizes patients into Low, Intermediate, or High probability groups based on clinical and laboratory features.

Usage

acute_gout_diagnosis(sex, prev_attack, onset_1day, joint_redness,
                     mtp1_involvement, htn_cvd, uric_acid_elevated)

Arguments

sex	String. Patient sex ("Male" or "Female"). (Male sex adds +2 points).
prev_attack	Numeric (0 or 1). Patient-reported previous arthritis attack. (1 = Yes, +2 points).
onset_1day	Numeric (0 or 1). Onset of symptoms within 1 day (maximal pain <24 hours). (1 = Yes, +0.5 points).
joint_redness	Numeric (0 or 1). Observed joint redness. (1 = Yes, +1 point).
mtp1_involvement	Numeric (0 or 1). Involvement of the 1st metatarsophalangeal (MTP1) joint. (1 = Yes, +2.5 points).
htn_cvd	Numeric (0 or 1). Presence of Hypertension or >= 1 Cardiovascular Disease (Angina, MI, Heart Failure, CVA, TIA, or PVD). (1 = Yes, +1.5 points).
uric_acid_elevated	Numeric (0 or 1). Serum Uric Acid > 5.88 mg/dL (> 0.35 mmol/L). (1 = Yes, +3.5 points).

Value

A list containing:

Total_Score	The calculated score (Range 0-13).
Probability	Estimated probability of gout (<2.2%, ~31%, or >80%).
Recommendation	Diagnostic guidance (Rule out, Test Fluid, or Treat).

References

Janssens HJ, Fransen J, van de Lisdonk EH, et al. A diagnostic rule for acute gouty arthritis in primary care without joint fluid analysis. Arch Intern Med. 2010;170(13):1120-1126. doi:10.1001/archinternmed.2010.196

Examples

# Example 1: High Probability
# Male, Previous Attack, Rapid Onset, MTP1, HTN, High Uric Acid
# Score = 2 + 2 + 0.5 + 2.5 + 1.5 + 3.5 = 12
acute_gout_diagnosis("male", 1, 1, 0, 1, 1, 1)

# Example 2: Low Probability
# Female, Rapid Onset, Redness, No other features
# Score = 0.5 + 1 = 1.5
acute_gout_diagnosis("female", 0, 1, 1, 0, 0, 0)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.