cliot (version 1.0.0)

acute_gout_diagnosis: 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)

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).

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).

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)