Predicting 60-Day Mortality in a Home-Care Service: Development of a New Inter-RAI 49-Frailty Index in Patients with Chronic Disease and without a Cancer Diagnosis

Objective: Frailty Index (FI) is used to define the level of frailty in various clinical settings. Fifteen- and 26-item FIs have been demonstrated to predict 1-year mortality and intensity of care in home care (HC) and palliative home care (PHC). The objective of this study was to develop a new FI to predict the 60-day risk of death or transition to a PHC service after the initiation of an HC service in patients with chronic disease and without a cancer diagnosis. Design: Retrospective cohort study. Setting and Participants: Patients 18 years and older followed in an HC service of a “Frailty Department-Local Palliative Care Network” from January 1, 2017, to October 31, 2021. Methods: A 49-item FI (FI-49) was developed selecting variables within the standardized international Residential Assessment Instrument assessments (interRAI-HC) and compared to existing FIs with 15 and 26 variables. Results: A total of 2099 patients were included in the study with a median age of 80.0 years (IQR: 72.0-86.0) and a predominantly female population (62.4%). Among these patients, 8% died or were transferred to PHC within the 60-day follow-up. The FI-49 demonstrated a higher ability to predict 60-day mortality (C index 0.8165, 95% CI 0.7848-0.8481) compared to the 26- and 15-item FI. An FI-49 cutoff of 0.33 was also selected to provide clinicians with a more practical approach (C-index of 0.7044, 95% CI 0.6796-0.7292). Conclusion and Implication: The FI-49 is a good predictor of short-term mortality or transition to palliative care among older patients referred to an HC service. The automatic calculation of this tool could facilitate more appropriate care planning and the correct allocation of healthcare resources, especially considering the rapid ageing of the population.