[Use of a proxy to the Charlson index to study the short and long-term comorbidity and mortality in the elderly].

Objectives: 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.

Design: Longitudinal study.

Setting: Population base, From "Aging in Leganes" cohort.