PROGNOSTIC FACTORS IN VERY OLD DEMENTED ADULTS - A 7-YEAR FOLLOW-UP FROM A POPULATION-BASED SURVEY IN STOCKHOLM

OBJECTIVE: To detect prognostic factors in very old demented subjects with Alzheimer's disease (AD), vascular dementia (VaD), and other type s of dementia (OD). DESIGN: Follow-up clinical examinations of dementi a patients from a population-based study after 3- and 7-year intervals . SETTING AND PARTICIPANTS: In an established population aged 75 years and older in Stockholm, Sweden, there were 133 cases of AD, 52 of VaD , and 38 of OD. MAIN OUTCOME MEASURES: Predictors of survival at 3- an d 7-year follow-up examinations were evaluated by Cox proportional haz ard models. Progression was measured as the annual rate of change in M ini-Mental State Examination (MMSE) scores. Linear models were used to evaluate predictors of progression. RESULTS: Older age, male gender, low education, comorbidity, and functional disability predicted shorte r 7-year survival in the 223 prevalent dementia cases. Other factors, including type of dementia, dementia severity, and duration of the dis ease were not significant. The average rate of cognitive decline in th e 81 mild to moderate demented subjects who survived 3 years was 2.4 M MSE points per year. Type of dementia (AD vs OD), higher baseline cogn itive function, and greater functional disability predicted faster dec line. Despite similar survival probability, predictors of death varied as a function of dementia type: Older age (for AD and VaD), comorbidi ty (for AD and OD), and functional dependency (for VaD). In AD, progno stic factors were similar to those described for the combined dementia groups, with the exception of an accelerated cognitive decline among women. CONCLUSIONS: Although methodological difficulties exist, it is possible to identify demented subjects with worse prognoses (shorter s urvival and faster cognitive decline) by using clinical and demographi c data. Clinicians and healthcare planners should be aware of the pote ntial usefulness of functional dependence as a prognostic indicator. F inally, the need for careful clinical examinations of demented subject s is stressed by the increased mortality found among those demented wh o are also affected by other chronic conditions.