The 3-Minute Diagnostic Confusion Assessment Method severity score correlates with the Delirium Rating Scale-Revised-98 and with biomarkers of delirium.

Background: Several methods are used to measure delirium severity in the postoperative period. Here, we compare severity scores from two common assessment methods: the 3-Minute Diagnostic Confusion Assessment Method (3D-CAM) and the Delirium Rating Scale-Revised-98 (DRS). Methods: Data were collected as part of an ongoing observational cohort study of perioperative delirium in patients >65 yr old undergoing major elective surgery with an anticipated hospital stay of at least 2 days. Patients were excluded if they had a documented history of dementia, resided in a nursing home, underwent neurosurgery, or could not complete neurocognitive testing. Patients underwent paired 3D-CAM and DRS assessments before and after operation along with EEG, cognitive testing, and plasma biomarker analysis. Results: Of 226 subjects enrolled, 204 completed both the 3D-CAM and DRS assessments. Peak 3D-CAM severity (3D-CAM-S) scores correlated with peak DRS severity scores, for both the raw (ρ=0.74, Conclusions: The 3D-CAM-S severity scores correlated with DRS, delirium duration, and biomarkers of delirium. The 3D-CAM, which is easier to implement than the DRS in postoperative patients, may provide a comparable assessment of delirium severity in this population. Clinical trial registration: NCT03124303.