title: [Use of a proxy to the Charlson index to study the short and long-term comorbidity and mortality in the elderly].
abstract: OBJECTIVE
  To design a proxy to the Charlson comorbidity index (PrCCI) for use in studies with pre-existing data sources and to analyse its influence on mortality risk in elderly people.
  
  
  METHODS
  Longitudinal study.
  
  
  METHODS
  Population base, From "Aging in Leganes" cohort.
  
  
  METHODS
  All individuals with complete information (n=978, aged 65 years old and older) were included in the construction of the proxy (PrCCI).
  
  
  METHODS
  A proxy (PrCCI) was created based on the original Charlson Comorbidity Index (CCI) and the available pre-existing data from the "Aging in Leganes" study. The relationship between PrCCI and mortality was assessed using a Survival analysis. Cox proportional Hazard Models were adjusted for possible confusion factors.
  
  
  RESULTS
  The PrCCI varied from 0 to 11 points (median=2 points, RI25-75=1-3). It was higher in women than in men until 79 years old, but no differences were found for both men and women from 80 years old. Individuals who scored four and more points in the new index had a higher mortality risk after 5 and 15 years of follow up, even after controlling for sociodemographic, health behaviours and health status related covariables (HR: 3.69, 95% CI: 1.52-8.96 and 2.14, 95% CI: 1.42-3.21, respectively).
  
  
  CONCLUSIONS
  The proxy to the Charlson comorbidity index is easy and useful to measure comorbidity in studies in population from 65 to 75 years old, which use pre-existing data bases and data available in the primary care setting. The association between PrCCI and mortality shows that it is useful as comorbidity index.
authors.affiliation: Departamento de Medicina Preventiva y Salud Pública, Cátedra UAM/Novartis de Medicina de Familia y Atención Primaria, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, España. aliciamisis@gmail.com
authors.forename: Alicia
authors.initials: A
authors.lastname: Gutiérrez-Misis
authors.forename: Maite
authors.initials: M
authors.lastname: Sánchez-Santos
authors.forename: Ángel
authors.initials: Á
authors.lastname: Otero
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity / Q000639:trends*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009026:Mortality / Q000639:trends*; D013997:Time Factors