Validation and Recalibration of Modified Mayo Delirium Prediction Tool in a Hospitalized Cohort

Background: Delirium prediction can augment and optimize care of older adults. Mayo Delirium Prediction (MDP) tool is a robust tool, developed from a large retrospective data set. The MDP tool predicts delirium risk for hospitalized older adults, within 24 hours of hospital admission, based on risk factor information available from electronic health record. Objective: We intend to validate the prediction performance of this tool and optimize the tool for clinical use. Methods: This is an observational cohort study conducted at Mayo Clinic Hospitals, Rochester, MN. All hospitalized older adults (age >50 years) from December 2019 to June 2020 were included. Patients with an admitting diagnosis of substance use disorder were excluded. The original MDP tool was modified to adjust for the fall risk variable as a binary variable that will facilitate broader applicability across different fall risk tools. The modified MDP tool was validated in the retrospective derivation and validation data set which yielded similar prediction capability (area under the receiver operating curve = 0.85 and 0.83, respectively). Diagnosis of delirium was captured by flowsheet diagnosis of delirium documented by nursing staff in the medical record. Predictive variable data were collected daily. Results: A total of 8055 patients were included in the study (median age 71 y). Delirium prediction of the modified MDP tool compared to delirium occurrence was 4% in the low-risk group, 17.8% in the medium-risk group, and 45.3% in the high-risk group (area under receiver operating curve of 0.80). Recalibration of the tool was attempted to further optimize the tool which resulted in both simplification and increased performance (area under receiver operating curve 0.82). The simplified tool was able to predict delirium in hospitalized patients admitted to both medical and surgical services. Conclusions: Validation of the modified MDP tool revealed good prediction capabilities. Recalibration resulted in simplification with increased performance of the tool in both medical and surgical hospitalized patients.