title: Age, time, and cohort effects on functional status and self-rated health in elderly men.
abstract: OBJECTIVE
  This study investigated age-related changes in functional status and self-rated health in elderly men, taking into account changes over time and differences between birth cohorts.
  
  
  METHODS
  The Zutphen Elderly Study is a longitudinal study of men born in the Netherlands between 1900 and 1920. Functional status and self-rated health were measured in 513 men in 1990, in 381 men in 1993, and in 340 men in 1995. Age, time, and cohort effects were analyzed in a mixed longitudinal model.
  
  
  RESULTS
  Longitudinal analyses showed that during 5 years of follow-up, the proportion of men without disabilities decreased from 53% to 39%, whereas the percentage who rated themselves as healthy decreased from 50% to 35%. Cross-sectional analyses confirmed changes in functional status, suggesting an age effect. Time-series analyses confirmed changes in self-rated health, suggesting a time effect. No birth-cohort effects were found.
  
  
  CONCLUSIONS
  Functional status deteriorates with age, whereas self-rated health is not related to age in men aged 70 years and older. The observed 5-year decline in self-rated health seemed to be due to a secular trend.
authors.affiliation: Department of Chronic Disease and Environmental Epidemiology, National Institute of Public Health and the Environment, Bilthoven, The Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Hoeymans
authors.forename: E J
authors.initials: EJ
authors.lastname: Feskens
authors.forename: G A
authors.initials: GA
authors.lastname: van den Bos
authors.forename: D
authors.initials: D
authors.lastname: Kromhout
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015988:Cohort Effect; D003430:Cross-Sectional Studies; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands; D011897:Random Allocation; D012650:Self Disclosure; D011795:Surveys and Questionnaires; D013997:Time Factors