The Prognostic Performance of Frailty for Delirium and Functional Decline in Vascular Surgery Patients

Background Frailty in older vascular surgery patients is associated with increased mortality, hospital stay, and morbidity. The association of frailty with hospital-acquired geriatric syndromes such as delirium and functional decline has not been well studied. Objectives To investigate the association between frailty and hospital-acquired geriatric syndromes in older hospitalized vascular surgery patients, and to evaluate the prognostic performance of the frailty index (FI) and the Clinical Frailty Scale (CFS) for delirium and functional decline. Design Prospective cohort study. Setting Acute care academic hospital. Participants Patients aged 65 years or more admitted to a tertiary vascular surgery unit (N=150). Measurements Frailty was assessed using the FI and CFS. The adjusted association of frailty status with delirium and functional decline was assessed using logistic regression analysis. The prognostic performance of FI and CFS was determined by assessing C-statistic and positive and negative predictive values (PPV and NPV). Results Of 150 participants, FI identified 34 (23%) and CFS identified 45 (30%) as frail. Frailty was an independent predictor of delirium (FI adjusted odds ratio, odds ratio (OR) = 5.66, 95% confidence interval (CI) = 1.53-21.03; CFS adjusted OR = 4.07, 95% CI = 1.14-14.50), but not functional decline. FI and CFS showed acceptable prognostic performance for delirium (C-statistic 0.74), but not functional decline (C-statistic 0.63-0.64). For both outcomes, the FI and CFS had high NPV (86-96%), and low PPV (22-29%). Conclusion Frail older vascular surgery patients are more likely to develop hospital-acquired geriatric syndromes. The FI and CFS have acceptable prognostic performance for predicting delirium but not all individuals who are identified as frail develop delirium. Ongoing research is needed to identify interventions that improve outcomes in patients who screen positive for frailty.