Short Physical Performance Battery as a Crosswalk Between Frailty Phenotype and Deficit Accumulation Frailty Index

Abstract

Background: Growing evidence supports the clinical importance of evaluating frailty in older adults, with its strong outcome relevance. We aimed to assess whether the Short Physical Performance Battery (SPPB) correlates with frailty status according to phenotype and deficit accumulation models and can be used as a link between these models.

Methods: We analyzed records of 1064 individuals from the Aging Study of Pyeongchang Rural Area, a population-based, prospective cohort from South Korea. Frailty was determined using the Cardiovascular Health Study (CHS) phenotype (phenotype model), 26- and 34-item frailty indices (deficit accumulation model). Associations of SPPB score and frailty with a composite outcome of mortality or long-term institutionalization were assessed. Crosswalks for SPPB, the CHS frailty phenotype, and the frailty index were created.

Results: The mean age of the study population was 76.0 years, and 583 (54.8%) were women. According to the CHS phenotype, 26- and 34-item frailty indices, 242 (22.7%), 161 (15.1%), and 280 (26.3%) participants, respectively, had frailty. Sensitivities/specificities for classifying CHS phenotype, 26- and 34-item frailty indices were 0.93/0.55, 0.71/0.84, and 0.80/0.83 by SPPB cut points of ≤9, ≤6, and ≤7, respectively. C-index of SPPB score (0.78) showed a predictive ability for the composite outcome that was comparable to that of CHS frailty phenotype (0.79), 26- (0.78), and 34-item frailty indices (0.79).

Conclusions: We could create a crosswalk linking frailty phenotype and frailty index from correlations between SPPB and frailty models. This result may facilitate clinical adoption of the frailty concept in a broader spectrum of older adults.

Keywords: Frailty; Functional performance; Physical performance.

© The Author(s) 2021. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Figures

Figure 1.

(A) Box plot showing distributions of the frailty index according to Short Physical Performance Battery (SPPB) scores. Numbers on the top of each box plot denote the mean frailty index by SPPB scores. (B) Bar plot showing proportions of robust, prefrail, and frail individuals categorized using the Cardiovascular Health Study frailty phenotype according to SPPB scores. In box plot, upper, mid, and lower lines of the box denote 75th, 50th, and 25th percentiles, respectively. Upper and lower margins of whiskers denote ±1.5 interquartile range from 50th percentile. Data outside ±1.5 interquartile range from 50th percentile are shown as an outlier.

Figure 2.

A crosswalk between corresponding scores of the 34-item frailty index, the Short Physical Performance Battery (SPPB), and the Cardiovascular Health Study (CHS) frailty phenotype, using equipercentile equating methods.