title: Degree of cognitive impairment and mortality: a 17-year follow-up in a community study.
abstract: BACKGROUND
  To test the hypothesis that cognitive impairment in older adults is associated with all-cause mortality risk and the risk increases when the degree of cognitive impairment augments; and then, if this association is confirmed, to report the population-attributable fraction (PAF) of mortality due to cognitive impairment.
  
  
  METHODS
  A representative random community sample of individuals aged over 55 was interviewed, and 4557 subjects remaining alive at the end of the first year of follow-up were included in the analysis. Instruments used in the assessment included the Mini-Mental Status Examination (MMSE), the History and Aetiology Schedule (HAS) and the Geriatric Mental State (GMS)-AGECAT. For the standardised degree of cognitive impairment Perneczky et al's MMSE criteria were applied. Mortality information was obtained from the official population registry. Multivariate Cox proportional hazard models were used to test the association between MMSE degrees of cognitive impairment and mortality risk. We also estimated the PAF of mortality due to specific MMSE stages.
  
  
  RESULTS
  Cognitive impairment was associated with mortality risk, the risk increasing in parallel with the degree of cognitive impairment (Hazard ratio, HR: 1.18 in the 'mild' degree of impairment; HR: 1.29 in the 'moderate' degree; and HR: 2.08 in the 'severe' degree). The PAF of mortality due to severe cognitive impairment was 3.49%.
  
  
  CONCLUSIONS
  A gradient of increased mortality-risk associated with severity of cognitive impairment was observed. The results support the claim that routine assessment of cognitive function in older adults should be considered in clinical practice.
authors.affiliation: Department of Preventive Medicine and Public Health,Universidad de Zaragoza,Zaragoza,Spain.
authors.forename: J
authors.initials: J
authors.lastname: Santabárbara
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: R
authors.initials: R
authors.lastname: Lopez-Anton
authors.affiliation: Department of Preventive Medicine and Public Health,Universidad de Zaragoza,Zaragoza,Spain.
authors.forename: G
authors.initials: G
authors.lastname: Marcos
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: C
authors.initials: C
authors.lastname: De-la-Cámara
authors.affiliation: Department of Preventive Medicine and Public Health,Universidad de Zaragoza,Zaragoza,Spain.
authors.forename: E
authors.initials: E
authors.lastname: Lobo
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: P
authors.initials: P
authors.lastname: Saz
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: P
authors.initials: P
authors.lastname: Gracia-García
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: T
authors.initials: T
authors.lastname: Ventura
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: A
authors.initials: A
authors.lastname: Campayo
authors.affiliation: Hospital Universitario de Getafe and Red Tematica de Investigacion Cooperativa en Envejecimiento y Fragilidad (RETICEF),Madrid,Spain.
authors.forename: L
authors.initials: L
authors.lastname: Rodríguez-Mañas
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: B
authors.initials: B
authors.lastname: Olaya
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Haro
authors.affiliation: Centre for Disability Research and Policy,Faculty of Health Sciences,University of Sydney,Sydney,Australia.
authors.forename: L
authors.initials: L
authors.lastname: Salvador-Carulla
authors.affiliation: Association for the Improvement of Mental Health Programmes (AMH),Geneva,Switzerland.
authors.forename: N
authors.initials: N
authors.lastname: Sartorius
authors.affiliation: Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM),Ministry of Science and Innovation,Madrid,Spain.
authors.forename: A
authors.initials: A
authors.lastname: Lobo
keywords: Cognitive impairment; Mini Mental Status Examination; mortality; population-attributable fraction