title: Simultaneous temporal trends in dementia incidence and prevalence, 2005-2013: a population-based retrospective cohort study in Saskatchewan, Canada.
abstract: Original studies published over the last decade regarding time trends in dementia report mixed results. The aims of the present study were to use linked administrative health data for the province of Saskatchewan for the period 2005/2006 to 2012/2013 to: (1) examine simultaneous temporal trends in annual age- and sex-specific dementia incidence and prevalence among individuals aged 45 and older, and (2) stratify the changes in incidence over time by database of identification.
  
  
  
  Using a population-based retrospective cohort study design, data were extracted from seven provincial administrative health databases linked by a unique anonymized identification number. Individuals 45 years and older at first identification of dementia between April 1, 2005 and March 31, 2013 were included, based on case definition criteria met within any one of four administrative health databases (hospital, physician, prescription drug, and long-term care).
  
  
  
  Between 2005/2006 and 2012/2013, the 12-month age-standardized incidence rate of dementia declined significantly by 11.07% and the 12-month age-standardized prevalence increased significantly by 30.54%. The number of incident cases decreased from 3,389 to 3,270 and the number of prevalent cases increased from 8,795 to 13,012. Incidence rate reductions were observed in every database of identification.
  
  
  
  We observed a simultaneous trend of decreasing incidence and increasing prevalence of dementia over a relatively short 8-year time period from 2005/2006 to 2012/2013. These trends indicate that the average survival time of dementia is lengthening. Continued observation of these time trends is warranted given the short study period.
authors.affiliation: Canadian Centre for Health and Safety in Agriculture,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Julie G
authors.initials: JG
authors.lastname: Kosteniuk
authors.affiliation: Canadian Centre for Health and Safety in Agriculture,University of Saskatchewan,103 Hospital Drive,Saskatoon,Saskatchewan,Canada.
authors.forename: Debra G
authors.initials: DG
authors.lastname: Morgan
authors.affiliation: Department of Psychology,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Megan E
authors.initials: ME
authors.lastname: O'Connell
authors.affiliation: Division of Neurology,College of Medicine,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Andrew
authors.initials: A
authors.lastname: Kirk
authors.affiliation: Department of Psychology (Professor Emerita),University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Margaret
authors.initials: M
authors.lastname: Crossley
authors.affiliation: Saskatchewan Health Quality Council,Saskatoon,Saskatchewan,Canada.
authors.forename: Gary F
authors.initials: GF
authors.lastname: Teare
authors.affiliation: College of Nursing,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Norma J
authors.initials: NJ
authors.lastname: Stewart
authors.affiliation: School of Rehabilitation Science,McMaster University,Hamilton,Ontario,Canada.
authors.forename: Vanina Dal
authors.initials: VD
authors.lastname: Bello-Haas
authors.affiliation: Indigenous Studies,First Nations University,Prince Albert,Saskatchewan,Canada.
authors.forename: Lesley
authors.initials: L
authors.lastname: McBain
authors.affiliation: Johnson Shoyama Graduate School of Public Policy,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Haizhen
authors.initials: H
authors.lastname: Mou
authors.affiliation: Faculty of Nursing,University of Alberta,Edmonton,Alberta,Canada.
authors.forename: Dorothy A
authors.initials: DA
authors.lastname: Forbes
authors.affiliation: Faculty of Social Sciences,University of Stirling,Stirling,UKandSalford Institute for Dementia,University of Salford,Manchester,UK.
authors.forename: Anthea
authors.initials: A
authors.lastname: Innes
authors.affiliation: Saskatchewan Health Quality Council,Saskatoon,Saskatchewan,Canada.
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Quail
mesh_terms: D000367:Age Factors; D000368:Aged; D016208:Databases, Factual; D003704:Dementia / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008134:Long-Term Care / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians' / Q000639:trends*; D015995:Prevalence; D012189:Retrospective Studies; D012525:Saskatchewan / Q000453:epidemiology; D012737:Sex Factors
keywords: administrative data; dementia; diagnosis; epidemiology; hospital; long-term care; physician; prescription drug