Predictive performance of four frailty measures in an older Australian population.
BACKGROUND
There are several different frailty measures available for identifying the frail elderly. However, their predictive performance in an Australian population has not been examined.


OBJECTIVE
To examine the predictive performance of four internationally validated frailty measures in an older Australian population.


METHODS
A retrospective study in the Australian Longitudinal Study of Ageing (ALSA) with 2,087 participants. Frailty was measured at baseline using frailty phenotype (FP), simplified frailty phenotype (SFP), frailty index (FI) and prognostic frailty score (PFS). Odds ratios (OR) were calculated to measure the association between frailty and outcomes at Wave 3 including mortality, hospitalisation, nursing home admission, fall and a combination of all outcomes. Predictive performance was measured by assessing sensitivity, specificity, positive and negative predictive values (PPV and NPV) and likelihood ratio (LR). Area under the curve (AUC) of dichotomised and the multilevel or continuous model of the measures was examined.


RESULTS
Prevalence of frailty varied from 2% up to 49% between the measures. Frailty was significantly associated with an increased risk of any outcome, OR (95% confidence interval) for FP: 1.9 (1.4-2.8), SFP: 3.6 (1.5-8.8), FI: 3.4 (2.7-4.3) and PFS: 2.3 (1.8-2.8). PFS had high sensitivity across all outcomes (sensitivity: 55.2-77.1%). The PPV for any outcome was highest for SFP and FI (70.8 and 69.7%, respectively). Only FI had acceptable accuracy in predicting outcomes, AUC: 0.59-0.70.


CONCLUSIONS
Being identified as frail by any of the four measures was associated with an increased risk of outcomes; however, their predictive accuracy varied.
Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
Imaina S
IS
Widagdo
Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
Nicole
N
Pratt
Occupational Therapy Board, Australian Health Practitioner Regulation Agency, Melbourne, VIC, Australia.
Mary
M
Russell
Quality Use of Medicines and Pharmacy Research Centre, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
Elizabeth E
EE
Roughead
D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity
Australia; frail elderly; older people; sensitivity; specificity