2015-2016 Normative Data for the 3-m Usual Walk, Five Repeated Chair Stands, and Static Balance Components of the SPPB among U.S. Older Adults Across Two Nationally Representative Data Sets: NSHAP and NHATS

Objectives: Our primary objective was to examine the distribution of 3-m usual walk, five repeated chair stands, and three static balance stance performances among age and gender subgroups of adults at least 65 years in two national data sets. We secondarily determined whether demographic-function associations varied across data sets, birth cohorts, or models incorporating data from those "unable to do"tasks. Methods: Two nationally representative data sets were used to generate survey weight-adjusted performance distributions: the 2015-2016 National Social Life Health and Aging Project and the 2016 National Health and Aging Trends Study. We then regressed walk and chair stand performance on age, gender, and race/ethnicity, examining differences across data sets, birth cohorts (1920-1947, 1948-1965), and before/after incorporating the "unable to do"performers. Results: Findings confirmed the gradual decline in function with age and allowed estimation of "relative"performance within age/gender subgroups. Data set distribution differences were noted, possibly due to recruitment, eligibility, and protocol variations. Demographic associations were similar across data sets but generally weaker among the 1948-1965 cohort and in models including the sizable "unable to do"group. Discussion: We present the largest, most current Short Physical Performance Battery reference data in U.S. adults aged 65 or older. Findings support standardization of administration protocols in research and clinical care and differentiating absolute from relative performance.