Comparing the predictive accuracy of frailty, comorbidity, and disability for mortality: a 1-year follow-up in patients hospitalized in geriatric wards

BACKGROUND: Studies evaluating and comparing the power of frailty, comorbidity, and disability instruments, together and in parallel, for predicting mortality are limited. OBJECTIVE: This study aimed to evaluate and compare the measures of frailty, comorbidity, and disability in predicting 1-year mortality in geriatric inpatients. DESIGN: Prospective cohort study. PATIENTS AND SETTING: A total of 307 inpatients aged ≥65 years in geriatric wards of a general hospital participated in the study. MEASUREMENTS: The patients were evaluated in relation to different frailty, comorbidity, and disability instruments during their hospital stays. These included three frailty (the seven-category Clinical Frailty Scale [CFS-7], a 41-item frailty index [FI], and the FRAIL scale), two comorbidity (the Cumulative Illness Rating Scale for Geriatrics [CIRS-G] and the comorbidity domain of the FI [Comorbidity-D-FI]), and two disability instruments (disability in basic activities of daily living [ADL-Katz] and the instrumental and basic activities of daily living domains of the FI [IADL/ADL-D-FI]). The patients were followed-up over 1 year. RESULTS: Using FI, CIRS-G, Comorbidity-D-FI, and ADL-Katz, this study identified a patient group with a high (≥50%) 1-year mortality rate in all of the patients and the two patient subgroups (ie, patients aged 65–82 years and ≥83 years). The CFS-7, FI, FRAIL scale, CIRS-G, Comorbidity-D-FI, and IADL/ADL-D-FI (analyzed as full scales) revealed useful discriminative accuracy for 1-year mortality (ie, an area under the curve >0.7) in all the patients and the two patient subgroups (all P<0.001). Thereby, CFS-7 (in all patients and the two patient subgroups) and FI (in the subgroup of patients aged ≥83 years) showed greater discriminative accuracy for 1-year mortality compared to other instruments (all P<0.05). CONCLUSION: All the different instruments emerged as suitable tools for risk stratification in geriatric inpatients. Among them, CFS-7, and in those patients aged ≥83 years, also the FI, might most accurately predict 1-year mortality in the aforementioned group of individuals.