title: On rational use of the cross-sectional method in analysis of the dynamics of biological indices with aging.
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D003430:Cross-Sectional Studies; D004812:Epidemiologic Methods; D006801:Humans; D008213:Lymphocyte Activation; D008875:Middle Aged; D008962:Models, Theoretical; D009026:Mortality; D011157:Population Dynamics; D011336:Probability