title: Patterns of cognitive performance in healthy ageing in Northern Portugal: a cross-sectional analysis.
abstract: BACKGROUND
  The Minho Integrative Neuroscience Database (MIND)-Ageing project aims to identify predictors of healthy cognitive ageing, including socio-demographic factors. In this exploratory analysis we sought to establish baseline cohorts for longitudinal assessment of age-related changes in cognition.
  
  
  METHODS
  The population sample (472 individuals) was strictly a convenient one, but similar to the Portuguese population in the age profile. Participants older than 55 years of age were included if they did not present defined disabling pathologies or dementia. A standardized clinical interview was conducted to assess medical history and a battery of neuropsychological tests was administered to characterize global cognition (Mini Mental State Examination), memory and executive functions (Selective Reminding Test; Stroop Color and Word Test; and Block Design subtest of the Wechsler Adult Intelligence Scale). Cross-sectional analysis of the neuropsychological performance with individual characteristics such as age, gender, educational level and setting (retirement home, senior university, day care center or community), allowed the establishment of baseline clusters for subsequent longitudinal studies.
  
  
  RESULTS
  Based on different socio-demographic characteristics, four main clusters that group distinctive patterns of cognitive performance were identified. The type of institution where the elders were sampled from, together with the level of formal education, were the major hierarchal factors for individual distribution in the four clusters. Of notice, education seems to delay the cognitive decline that is associated with age in all clusters.
  
  
  CONCLUSIONS
  Social-inclusion/engagement and education seem to have a protective effect on mental ageing, although this effect may not be effective in the eldest elders.
authors.affiliation: Life and Health Sciences Research Institute, ICVS, School of Health Sciences, University of Minho, Braga, Portugal.
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Paulo
authors.forename: Adriana
authors.initials: A
authors.lastname: Sampaio
authors.forename: Nadine Correia
authors.initials: NC
authors.lastname: Santos
authors.forename: Patrício Soares
authors.initials: PS
authors.lastname: Costa
authors.forename: Pedro
authors.initials: P
authors.lastname: Cunha
authors.forename: Joseph
authors.initials: J
authors.lastname: Zihl
authors.forename: João
authors.initials: J
authors.lastname: Cerqueira
authors.forename: Joana Almeida
authors.initials: JA
authors.lastname: Palha
authors.forename: Nuno
authors.initials: N
authors.lastname: Sousa
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003071:Cognition; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D016012:Poisson Distribution; D011174:Portugal