Validation of Frail Scale and comparison with hospital frailty risk score to predict hospital use in a cohort of older Australian women.

Introduction: With no standard frailty tool for clinical care, research and policymaking, identifying frail older people is a challenge.

Aims: This study aimed to compare two validated scales, which are the Frail Scale and Hospital Frailty Risk Score (HFRS) for their ability in identifying frailty in older Australian women and predicting hospital use.

Methods: This study included older Australian women aged 75-95 years, who had unplanned overnight hospital admission as an index admission between 2001 and 2016. Data from the Australian Longitudinal Study on Women's Health (ALSWH) were linked with administrative hospital data to calculate HFRS (using the International Statistical Classification of Diseases, Australia Modification (ICD-10-AM) diagnostic codes) and the Frail Scale (using the ALSWH self-reported survey).

Results: The Frail Scale identified a higher proportion of older frail women (30.54%) compared to the HFRS (23.0%). Frail older women, classified by Frail Scale, were at higher risk of long hospital stay (adjusted odds ratio = 1.28, 95% CI = 1.02-1.60), repeated admission (adjusted hazard ratio [AHR] = 1.30, 95% CI = 1.03-1.41) and death (AHR = 1.70, 95% CI = 1.45-2.01). HFRS was associated with longer hospital stay and mortality.

Conclusions: The proportion of older women classified as frail by the Frail Scale tool was higher than women classified as frail by HFRS. The Frail Scale and HFRS were not significantly associated with each other. While both tools were associated with the risk of long hospital stay and mortality, only the Frail Scale predicted the risk of repeated admission.