In Reply: Dr Wei raises a concern about the identical rates of physical inactivity between survivors and decedents.
Self-reported physical activity is likely a crude approximation of actual physical activity, and misclassification may be high because activity assessment tends to be incomplete when based on questionnaires such as ours and others.1,2
Sui X, Blair SN. Cardiorespiratory Fitness, Adiposity, and Mortality—Reply. JAMA. 2008;299(9):1013-1014. doi:10.1001/jama.299.9.1014-a