Decision tree prediction of saline infusion test outcomes in suspected primary aldosteronism: a multicenter common data model study

CONTEXT: Confirmatory aldosterone suppression testing is widely utilized following positive screening for primary aldosteronism (PA), yet its incremental diagnostic value remains debated. While the 2025 Endocrine Society guideline proposes a probability-based approach, validated tools to translate this concept into clinical decision-making, particularly in Asian populations, are lacking. METHODS: Using a multicenter Common Data Model (CDM) across three tertiary hospitals (2002-2020), we retrospectively identified 307 patients who underwent SIT for suspected PA. SIT positivity was defined as post-infusion plasma aldosterone concentration (PAC) ≥10 ng/dL. We developed a conditional inference classification tree using screening-stage variables and compared its performance with conventional rigid screening criteria based on PAC and the aldosterone-to-renin ratio (ARR). RESULTS: Among 307 patients (mean age 51.2 years), 153 (49.8%) were SIT-positive. SIT-positive patients had higher PAC (median 32.9 vs. 12.7 ng/dL, p