A Comparison of Frailty Indexes for the Prediction of Falls, Disability, Fractures, and Mortality in Older Men

Abstract

To compare the validity of a parsimonious frailty index (components: weight loss, inability to rise from a chair, and poor energy (Study of Osteoporotic Fractures (SOF) index)) with that of the more complex Cardiovascular Health Study (CHS) index (components: unintentional weight loss, low grip strength, poor energy, slowness, and low physical activity) for prediction of adverse outcomes in older men. Prospective cohort study. Six U.S. centers. Three thousand one hundred thirty-two men aged 67 and older. Frailty status categorized as robust, intermediate stage, or frail using the SOF index and criteria similar to those used in CHS index. Falls were reported three times for 1 year. Disability (>or=1 new impairments in performing instrumental activities of daily living) ascertained at 1 year. Fractures and deaths ascertained during 3 years of follow-up. Analysis of area under the receiver operating characteristic curve (AUC) statistics compared for models containing the SOF index versus those containing the CHS index. Greater evidence of frailty as defined by either index was associated with greater risk of adverse outcomes. Frail men had a higher age-adjusted risk of recurrent falls (odds ratio (OR)=3.0-3.6), disability (OR=5.3-7.5), nonspine fracture (hazard ratio (HR)=2.2-2.3), and death (HR=2.5-3.5) (P<.001 for all models). AUC comparisons revealed no differences between models with the SOF index and models with the CHS index in discriminating falls (AUC=0.63, P=.97), disability (AUC=0.68, P=.86), nonspine fracture (AUC=0.63, P=.90), or death (AUC=0.71 for model with SOF index and 0.72 for model with CHS index, P=.19). The simple SOF index predicts risk of falls, disability, fracture, and mortality in men as well as the more-complex CHS index.