Frailty level at discharge predicts mortality in older patients with Clostridioides difficile more accurately than age or disease severity

PURPOSE: Clostridioides difficile infection (CDI) has a high mortality among older patients. Identification of older patients with CDI in increased mortality risk is important to target treatment and thereby reduce mortality. The aim of this study was to investigate mortality rates and compare frailty levels at discharge, measured by the record-based Multidimensional Prognostic Index (MPI), with age and severity of CDI as mortality predictors in patients with CDI diagnosed during hospitalisation. METHODS: This was a population-based cohort study from Central Denmark Region, Denmark, including all patients ≥ 60 years with a positive CD toxin test without prior infection and diagnosed from 1 January to 31 December 2018. Frailty level, estimated from the electronic medical record, was defined as low, moderate, or severe frailty. CDI severity was graded according to international guidelines. Primary outcome was 90-day mortality. RESULTS: We included 457 patients with median age 77 years (interquartile range 69–84) and females (49%). Overall, 90-day mortality was 28%, and this was associated with age (hazard ratio (HR): 2.71 (95% confidence interval 1.64–4.47)), CDI severity (HR 4.58 (3.04–6.88)) and frailty (HR 10.15 (4.06–25.36)). Frailty was a better predictor of 90-day mortality than both age (p < 0.001) and CDI severity (p = 0.04) with a receiver operating characteristic curve area of 77%. CONCLUSION: The 90-day mortality among older patients with CDI in a Danish region is 28%. Frailty measured by record-based MPI at discharge outperforms age and disease severity markers in predicting mortality in older patients with CDI.