Is Frailty a Predictor of Outcomes in Elderly Inpatients with Acute Kidney Injury? A Prospective Cohort Study

Background Frailty and acute kidney injury are independently associated with an increased risk of morbidity and mortality. The degree of frailty can be assessed by the Clinical Frailty Score (CFS). This study assessed whether an individual's CFS was associated with acute kidney injury in acute elderly medical admissions and recorded the short-term outcomes. Methods This was a single-center prospective observational cohort study. All patients aged ≥65 years admitted under an acute medical take over 12 nonconsecutive days were included. Patient demographics, comorbidities, baseline CFS, and renal status on admission were recorded. Outcomes of death, length of stay, and hospital re-attendance were assessed 2 weeks following admission. Results Of 164 patients (77 males), 19% had acute kidney injury on admission and 22% were considered severely frail. Severe frailty was associated with acute kidney injury (P = .01) and death within 2 weeks (P = .01). Two-week mortality was highest among patients with both (36%). Conclusion The incidence of acute kidney injury in "severely frail" acutely unwell elderly patients is significantly higher and associated with an increased short-term mortality. The CFS may be useful in acute illness to guide clinical decisions in elderly patients.