Time orientation and executive functions in the prediction of mortality in the elderly: Epidoso study

Abstract

OBJECTIVE: To analyze the predictive ability of a functional cognitive index of mortality in the elderly. METHODS: Cohort study performed with 1,667 elderly individuals aged more than 65 years and living in the city of São Paulo, Southeastern Brazil, between 1991 and 2001. Functional cognitive index was constructed from time orientation and executive functions (going shopping and taking medication), controlled by sociodemographic variables, life habits, morbidity, self-perception of health, hospitalization, edentulism and social support. Deaths occurred during this period were analyzed with family members in home interviews, notary public offices and records from the Fundação Seade (State System of Data Analysis Foundation), until 2003. Crude and adjusted relative risks were calculated with their respective 95% confidence intervals, using bivariate and multiple analysis with Poisson regression and p<0.05. RESULTS: In the final multivariate model, the following independent risk factors were identified by the index: partial loss of time orientation or executive functions (RR=1.37; 95% CI: 1.03;1.83); total loss of orientation and partial loss of functions (RR=1.71; 95% CI: 1.24;2.37); partial loss of orientation and total loss of functions (RR=1.76; 95% CI: 1.35;2.28); and total loss of orientation and functions (RR=1.64; 95% CI: 1.30;2.06). As regards health conditions, the following were observed: hospitalization (RR=1.45; 95% CI: 1.22;1.73); diabetes (RR=1.20; 95% CI: 1.00;1.44); and total edentulism (RR=1.34; 95% CI: 1.09;1.66). Monthly contact with relatives was identified as a protective factor (RR=0.83; 95% CI: 0.69;1.00). CONCLUSIONS: The Functional Cognitive Index can help clinicians and health planners to make decisions on strategies for follow-up and prevention of treatable causes of cognitive deficit and functional loss to reduce mortality in the elderly.