title: Combining longitudinal studies showed prevalence of disease differed throughout older adulthood.
abstract: OBJECTIVE
  Disease prevalence rates are often generalized across the older adult age range. By pooling self-reported health data from five Australian longitudinal studies of aging, we were able to present disease prevalence rates by 5-year age bands and sex. We also investigated the influence of education on prevalence at each age range and compared our observed prevalence rates with those from the 2001 National Health Survey (NHS) to see if existing data could be used to augment national estimates.
  
  
  METHODS
  We used data on 12,718 adults between 60 and 105 years of age from the Dynamic Analyses to Optimise Ageing (DYNOPTA) project.
  
  
  RESULTS
  Hypertension and arthritis were the most prevalent diseases, with approximately 30% of males and 45% of females having either condition. Nearly all diseases were most prevalent amongst older adults in their 70s and lower for individuals in their 60s, and 80s and older. The effect of education varied by disease and older age group. Prevalence rates from DYNOPTA were generally similar to those reported by the NHS.
  
  
  CONCLUSIONS
  Disease prevalence is not consistent across older adulthood. Combining longitudinal studies provided a sufficient sample to estimate precise age divisions and can be used to supplement national estimates for specific populations.
authors.affiliation: Ageing Research Unit, Centre for Mental Health Research, The Australian National University, Canberra, Australian Capital Territory, Australia. allison.bielak@colostate.edu
authors.forename: Allison A M
authors.initials: AA
authors.lastname: Bielak
authors.forename: Julie E
authors.initials: JE
authors.lastname: Byles
authors.forename: Mary A
authors.initials: MA
authors.lastname: Luszcz
authors.forename: Kaarin J
authors.initials: KJ
authors.lastname: Anstey
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001168:Arthritis / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D002908:Chronic Disease / Q000453:epidemiology*; D003920:Diabetes Mellitus / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D006304:Health Status; D006306:Health Surveys / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D017678:Sex Distribution; D013997:Time Factors