DYNAMICS OF FUNCTIONAL IMPAIRMENT IN LATE ADULTHOOD

The inconclusive debate about Fries' theory of ''natural death and the compression of morbidity'' has diverted attention from two key issues -the modifiability and related dynamics of functional impairment in la te adulthood. Evidence is presented from a large (N = 11,000) panel of adults aged initially 58-63 over the period of a decade which documen ts substantial modification of functional status. Further, patterned c hanges in functional status are related to the dynamics of income, his torically a major determinant of functional status, and independently to educational attainment. The dynamics of functional status, of incom e, and of their relationship are explored using discrete time hazard m odels in an event history analysis incorporating time-varying income a nd functional status indicators. The importance of income and of educa tion as positive, independent predictors of functional status and patt erned changes of functional status is confirmed. The implications of t his finding for differentiating distal (e.g. education) and proximate (e.g. income) measures of socioeconomic status and for assessing compe ting theories of social causation and social selection are discussed.