Enhancing Delirium Prediction in ICU Older Patients Through the 5‐Factor Modified Frailty Index

BACKGROUND: Delirium and frailty are prevalent in the ICU, yet there is a paucity of research utilising frailty as determined by the 5-factor modified frailty index (mFI-5) to examine its correlation with delirium in intensive care unit (ICU) older patients. AIM: The aim of this research was to explore the association between the mFI-5 and the occurrence of delirium in older patients admitted to the ICU, while assessing the mFI-5's predictive value for delirium. STUDY DESIGN: This study employed data extracted from the Medical Information Mart for Intensive Care IV database. The participants were classified into three groups based on their mFI-5 scores: non-frail (mFI-5 = 0), intermediate frailty (mFI-5 = 1) and high frailty (mFI-5 ≥ 2). The predictive value of mFI-5 for delirium was evaluated using the area under the curve, the net reclassification improvement and the integrated discrimination improvement metrics. RESULTS: Delirium was observed in 9919 of the 30 280 patients included in the study. Patients with intermediate frailty (adjusted odds ratios [OR]: 1.38, 95% CI: 1.28-1.48, p < 0.001) and high frailty (adjusted OR: 1.83, 95% CI: 1.69-1.97, p < 0.001) exhibited a markedly elevated risk of delirium in comparison to non-frail patients. Furthermore, the incorporation of the mFI-5 into the multivariate model markedly enhanced its predictive accuracy for delirium. CONCLUSIONS: Frailty as assessed by the mFI-5 is strongly correlated with an elevated risk of delirium in older ICU patients. The incorporation of the mFI-5 into delirium prediction models may enhance the predictive accuracy of these models. RELEVANCE TO CLINICAL PRACTICE: The mFI-5 is a valuable tool for identifying older ICU patients at higher risk of delirium, aiding in early intervention and tailored care.