INTOXICATE-US: validation of the INTOXICATE model in an American health care system.

Abstract

Background: The INTOXICATE model was developed in the Netherlands to decrease unnecessary intensive care unit admissions for poisoned patients. It reduced admissions by one-third in a retrospective study of patients already admitted to the intensive care unit. This study evaluates the model in the United States.

Methods: We conducted a retrospective study of patients older than 12 years in one United States hospital system with a bedside toxicology service from 2023 to 2024. Our primary outcome was the number of patients admitted to the intensive care unit for whom INTOXICATE recommended against admission and who did not require critical care ("safe downgrades"). Our secondary outcome was the agreement between INTOXICATE and toxicologists as to which patients under evaluation in the emergency department would need critical care.

Results: We screened 112 patients and analyzed 101: 19 (18%) were admitted to the intensive care unit, 16 (16%) to a general medical floor, and 66 (65%) discharged or transferred directly to psychiatry. INTOXICATE identified five (26%) safe downgrades. In the emergency department, INTOXICATE recommended admission to the intensive care unit for 60% of patients, compared to 18% for toxicologists, and had no agreement with toxicologists (Cohen's kappa 0.04; 95% CI: -0.082 to 0.192) Adjusting the threshold of INTOXICATE for recommending admission to the intensive care unit improved agreement (Cohen's kappa 0.55; 95% CI: 0.294 to 0.801) and would have reduced admissions by 22% but also resulted in unsafe downgrades and one death within 30 days.

Discussion: For patients already admitted to the intensive care unit, INTOXICATE identified safe downgrades, consistent with prior findings. When applied in the emergency department to predict critical care needs, it tripled admissions and showed poor agreement with toxicologists.

Conclusion: More work is needed before INTOXICATE can prognosticate which emergency department patients need critical care as accurately as toxicologists.