[The geriatric syndrome frailty in the context of readmission to the intensive care unit : Study protocol of a mixed-methods study].

Background: Frailty syndrome is characterized by a decline in physiological reserves and a reduced resistance to internal and external stressors. In addition to a higher mortality rate, patients who are frail are more prone to complications during hospitalization, including admission to an intensive care unit (ICU). Studies indicated that frailty syndrome may serve as a predictor of readmission to the ICU. The impact of frailty syndrome on readmission to an ICU in Germany remains to be elucidated, as extant research primarily originates from non-German-speaking countries and is only partially transferable.

Aim: The primary objective of this study is to characterize the syndrome of frailty (measured using the Clinical Frailty Scale [CFS] ≥ 5) as a potential risk factor for readmission to the ICU. Secondly, the study will examine which factors, specifically nursing and medical measures on intermediate care and normal wards, can influence readmissions to the ICU.

Method: The study employs an explanatory sequential mixed-methods design, comprising a quantitative and a qualitative research phase. In the quantitative phase, a prospective cohort study will be conducted to investigate the association between frailty syndrome and ICU readmissions (≤ 30 days after discharge or during the same hospital stay) in patients ≥ 65 years of age. Concurrently, a document analysis will be conducted in the qualitative phase to identify care measures that could influence readmission.

Expected results: The primary hypothesis of this study is that patients diagnosed with frailty syndrome (CFS ≥ 5) exhibit a higher risk of readmission to the ICU compared to non-frail patients. This inquiry will be conducted in the quantitative phase of the study. The qualitative research component is designed to elucidate non-intensive care measures that may influence readmission.