Physical Function in U.S. Older Adults Compared With Other Populations: A Multinational Study.

We compare physical performance from three U.S. national surveys and nationally representative surveys in England, Taiwan, and Costa Rica. For each performance test, we use local mean smoothing to plot the age profiles by sex and survey wave and then fit a linear regression model to the pooled data, separately by sex, to test for significant differences across surveys controlling for age and height. Age profiles of performance vary across U.S. surveys, but levels of lung function (peak expiratory flow) and handgrip strength in the United States are as high as they are in the other three countries. Americans also perform as well on the chair stand test as the English and Costa Ricans, if not better, but exhibit slower gait speed than the English at most ages. With the exception of walking speed, we find little evidence that older Americans have worse physical performance than their peers.