Explainable Machine Learning to Bring Database to the Bedside: Development and Validation of the TROUT (Trauma fRailty OUTcomes) Index, a Point-of-Care Tool to Prognosticate Outcomes after Traumatic Injury based on Frailty. Annals of surgery Choi, J., Anderson, T., Tennakoon, L., Spain, D. A., Forrester, J. D. 2022

Abstract

Exemplify an explainable machine learning framework to bring database to the bedside; develop and validate a point-of-care frailty assessment tool to prognosticate outcomes after injury.A geriatric trauma frailty index that captures only baseline conditions, is readily-implementable, and validated nationwide remains underexplored. We hypothesized Trauma fRailty OUTcomes (TROUT) Index could prognosticate major adverse outcomes with minimal implementation barriers.We developed TROUT index according to Transparent Reporting of a Multivariable Prediction Model for Individual Prognosis guidelines. Using nationwide US admission encounters of patients aged =65 years (2016-2017; 10% development, 90% validation cohorts), unsupervised and supervised machine learning algorithms identified baseline conditions that contribute most to adverse outcomes. These conditions were aggregated into TROUT Index scores (0-100) that delineate three frailty risk strata. After associative (between frailty risk strata and outcomes, adjusted for age, sex, and injury severity [as effect modifier]) and calibration analysis, we designed a mobile application to facilitate point-of-care implementation.Our study population comprised 1.6 million survey-weighted admission encounters. Fourteen baseline conditions and one mechanism of injury constituted the TROUT Index. Among the validation cohort, increasing frailty risk (low=reference group, moderate, high) was associated with stepwise increased adjusted odds of mortality (OR[95%CI]: 2.6[2.4-2.8], 4.3[4.0-4.7]), prolonged hospitalization (OR[95%CI]: 1.4[1.4-1.5], 1.8 [1.8-1.9]), disposition to a facility (OR[95%CI]: 1.4[1.4-1.5], 1.8[1.7-1.8]), and mechanical ventilation (OR[95%CI]: 2.3[1.9-2.7], 3.6[3.0-4.5]). Calibration analysis found positive correlations between higher TROUT Index scores and all adverse outcomes. We built a mobile application ("TROUT Index") and shared code publicly.The TROUT Index is an interpretable, point-of-care tool to quantify and integrate frailty within clinical decision-making among injured patients. The TROUT Index is not a stand-alone tool to predict outcomes after injury; our tool should be considered in conjunction with injury pattern, clinical management, and within institution-specific workflows. A practical mobile application and publicly-available code can facilitate future implementation and external validation studies.

View details for DOI 10.1097/SLA.0000000000005649

View details for PubMedID 35920568