Combining the Hospital Frailty Risk Score With the Charlson and Elixhauser Multimorbidity Indices to Identify Older Patients at Risk of Poor Outcomes in Acute Care.

"The authors declare no conflict of interest."

"This study was supported by a grant from Hospices Civils de Lyon (direction de la recherche clinique et de l’innovation), France. The funding source had no influence in the design, data collection, interpretation of data, writing of the report, or decision to submit the article for publication."

"This study was conducted using the same cohort as the previously published validation study of the HFRS in metropolitan France. We conducted a retrospective analysis of anonymized secondary care data from the French nationwide Medical Information System [Programme de Médicalisation des Systèmes d’Information (PMSI), source: ATIH] database, which contains routinely collected data from electronic health records of all public and private hospitals in France (Trial Registration: reference ID on clinicaltrials.gov: ID: NCT03905629). We included all patients aged 75 years and older (on the day of the index admission) hospitalized as an emergency over a period of 1 year between January 1 and December 31, 2017. In case of multiple admissions of the same patient, the patients were only included once, considering the first (index) admission."