title: Later age at onset in Parkinson's disease over twenty years in an Italian tertiary clinic.
abstract: BACKGROUND
  Age is considered an important risk factor for Parkinson's disease (PD). However, although life-expectancy has increased considerably, incidence rates of PD appeared to be stable over the last two decades. Accordingly, an increase in mean age at onset over time could be expected. We investigated the changes in age at onset in PD over the last two decades.
  
  
  METHODS
  All consecutive PD patients assessed over a 18-year period (1995-2013) in a single tertiary outpatient clinic were included in the present retrospective cohort study.
  
  
  RESULTS
  After adjusting for several confounders (gender, positive family history for PD, education, smoking at onset and past exposure to environmental/occupational pollutants), 5-year cohorts of year of disease onset were associated with increasing age at onset in both prevalent (N = 6996) and incident (N = 4172) cases (for trend, P < 0.001). From 1995-2000 to 2010-2013 there was an increase in predicted age of 4.1 years (95% CI, 3.0-5.2) and 3.9 years (95% CI, 2.7-5.1) in prevalent and incident cases, respectively. However, the change in predicted age at PD onset, across cohorts of year at onset, showed a steeper increase than the corresponding sex and cohort-matched mean age from the official Italian statistics.
  
  
  CONCLUSIONS
  Over the last two decades, age at onset of PD appeared to shift progressively towards more advanced age. However, sequential, high-quality population-based incidence studies are required. To establish whether there is a trend towards increase in age at onset over and above general population ageing and to assess whether the increase is associated with improved medical and socio-economic conditions.
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Gianni
authors.initials: G
authors.lastname: Pezzoli
authors.affiliation: Biometry and Statistics Service, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
authors.forename: Catherine
authors.initials: C
authors.lastname: Klersy
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cilia
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Margherita
authors.initials: M
authors.lastname: Canesi
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Anna Lena
authors.initials: AL
authors.lastname: Zecchinelli
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Claudio Bruno
authors.initials: CB
authors.lastname: Mariani
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Silvana
authors.initials: S
authors.lastname: Tesei
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Sacilotto
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Nicoletta
authors.initials: N
authors.lastname: Meucci
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Zini
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Ioannis Ugo
authors.initials: IU
authors.lastname: Isaias
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Ruffmann
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Barichella
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Cassani
authors.affiliation: Parkinson Institute - Istituti Clinici di Perfezionamento, Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Goldwurm
authors.affiliation: Nutrition and Dietetics Service, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy. Electronic address: e.cereda@smatteo.pv.it.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Cereda
mesh_terms: D017668:Age of Onset; D000368:Aged; D015331:Cohort Studies; D018672:Community Health Planning; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*
keywords: Age at onset; Epidemiology; Parkinson's disease