title: Age, period and cohort analysis of patient dental visits in Australia.
abstract: BACKGROUND
  Understanding dentists' capacity to supply dental services over time is a key element in the process of planning for the future. The aim was to identify time trends and estimate age, period and cohort effects in patients' visits supplied per dentist per year.
  
  
  METHODS
  Mailed questionnaires were collected from a random sample of Australian private general practice dentists. The response rates were 73%, 75%, 74%, 71%, 76% and 67% in 1983, 1988, 1993, 1998, 2003 and 2009, respectively. The time trends in the mean number of patient visits supplied per dentist per year (PPY) was described by using a standard cohort table and age-period-cohort analyses applying a nested general linear regression models approach.
  
  
  RESULTS
  The mean number of PPY decreased across most age groups of dentists over the time of study. The age-period model showed that younger dentists (20-29 years) and older dentists (65-74 and 80-84 years) had lower PPY than middle-aged dentists, and the age-cohort model showed higher PPY among earlier cohorts, and lower PPY among more recent cohorts.
  
  
  CONCLUSIONS
  The study found a period effect of declining PPY over the observation period. More recent cohorts of dentists provide lower numbers of PPY than earlier cohorts at similar ages, but the provision of PPY among these younger cohorts appeared to be stable as they moved into middle age.
authors.forename: Xiangqun
authors.initials: X
authors.lastname: Ju
authors.affiliation: Australian Research Centre for Population Oral Health, The University of Adelaide, South Australia 5005, Australia. david.brennan@adelaide.edu.au.
authors.forename: David S
authors.initials: DS
authors.lastname: Brennan
authors.forename: A John
authors.initials: AJ
authors.lastname: Spencer
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D003729:Dental Care / Q000706:statistics & numerical data*; D003815:Dentists / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult