Frailty as a predictor of adverse outcomes in hospitalized older adults: A systematic review and meta-analysis

Frailty syndrome is prevalent among hospitalized older adults as are the occurrence of adverse outcomes. This systematic review and meta-analysis investigated whether frailty in older adults at hospital admission predicts adverse outcomes. Manual (ProQuest, conferences annals and references) and electronic searches (PUBMED, EMBASE, Web of Science, Lilacs, CINAHL, PsycINFO and Google Scholar) were performed. We included prospective studies of hospitalized older adults. Primary outcomes were functional decline at hospital discharge and mortality after discharge. Other data were considered secondary outcomes. Methodological quality was evaluated by the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Twenty-eight papers were included, corresponding to 19 cohorts (5 cohorts for functional decline and 16 for mortality), with moderate to good methodological quality. Being frail [RR: 1.32 (95%Cl: 1.04; 1.67)] and pre-frail [RR: 1.51 (95%Cl: 1.05; 2.17)] are risk factors for functional decline compared with being nonfrail. Frail individuals had a relative risk for in-hospital mortality and mortality in medium- and long-term compared to nonfrail (in-hospital RR: 8.20, medium RR: 9.49 and long RR: 7.94) and pre-frail (in-hospital RR: 3.19, medium RR: 3.31 and long RR: 3.72). The overall mortality risk in frail individuals is 3.49 and 2.14 times compared to nonfrail and pre-frail, respectively. Length of hospital stay was higher for frail older adults (13.5 days) compared with pre-frail (10.5 days) and nonfrail (8.3 days). Therefore, being frail at hospital admission is a risk factor for in-hospital mortality, long hospital stay, functional decline at hospital discharge, and mortality in the medium- and long-term.