Natural language processing diagnosed behavioral disturbance vs confusion assessment method for the intensive care unit: prevalence, patient characteristics, overlap, and association with treatment and outcome.

Purpose: To compare the prevalence, characteristics, drug treatment for delirium, and outcomes of patients with Natural Language Processing (NLP) diagnosed behavioral disturbance (NLP-Dx-BD) vs Confusion Assessment Method for intensive care unit (CAM-ICU) positivity.

Methods: In three combined medical-surgical ICUs, we obtained data on demographics, treatment with antipsychotic medications, and outcomes. We applied NLP to caregiver progress notes to diagnose behavioral disturbance and analyzed simultaneous CAM-ICU.

Results: We assessed 2313 patients with a median lowest Richmond Agitation-Sedation Scale (RASS) score of - 2 (- 4.0 to - 1.0) and median highest RASS score of 1 (0 to 1). Overall, 1246 (53.9%) patients were NLP-Dx-BD positive (NLP-Dx-BD) and 578 (25%) were CAM-ICU positive (CAM-ICU). Among NLP-Dx-BD patients, 539 (43.3%) were also CAM-ICU. In contrast, among CAM-ICU patients, 539 (93.3%) were also NLP-Dx-BD. The use of antipsychotic medications was highest in patients in the CAM-ICU and NLP-Dx-BD group (24.3%) followed by the CAM-ICU and NLP-Dx-BD group (10.5%). In NLP-Dx-BD patients, antipsychotic medication use was lower at 5.1% for CAM-ICU and NLP-Dx-BD patients and 2.3% for CAM-ICU and NLP-Dx-BD patients (overall P < 0.001). Regardless of CAM-ICU status, after adjustment and on time-dependent Cox modelling, NLP-Dx-BD was associated with greater antipsychotic medication use. Finally, regardless of CAM-ICU status, NLP-Dx-BD patients had longer duration of ICU and hospital stay and greater hospital mortality (all P < 0.001).

Conclusion: More patients were NLP-Dx-BD positive than CAM-ICU positive. NLP-Dx-BD and CAM-ICU assessment describe partly overlapping populations. However, NLP-Dx-BD identifies more patients likely to receive antipsychotic medications. In the absence of NLP-Dx-BD, treatment with antipsychotic medications is rare.