Cognitive impairment and mortality in older community residents.

Abstract

OBJECTIVE. Cognitive impairment among the elderly has been linked to mortality in studies of clinical populations. The purpose of this study was to examine the mortality risk associated with cognitive impairment among elderly populations in the community. METHODS. Cognitive impairment and other social and health factors were assessed in 1855 elderly community residents. This sample was reinterviewed periodically to assess changes in health and survival. RESULTS. At baseline 33% of the sample were mildly impaired and 8% were severely impaired. Across a 48-month observation period the survival probability was .85 for the cognitively unimpaired, .69 for the mildly impaired, and .51 for severely impaired respondents. When adjustments were made for the effects of other health and social covariates, severely impaired persons were twice as likely to die as unimpaired persons. Those who were mildly impaired were also at an increased risk. CONCLUSIONS. Other investigators have found that cognitive impairment is a significant predictor of dementia. We found that it is a significant predictor of mortality as well. Early detection of impaired cognition and attention to associated health problems could improve the quality of life of these older adults and perhaps extend their survival.

Cognitive Functioning and Health as Determinants of Mortality in an Older Population

“…Some studies have reported weak abilities to predict mortality (45), whereas others have described memory as a strong predictor (3,9). Contrary to our findings, several studies have reported the MMSE to be a good predictor of mortality (11,17,46). These studies did not include such a broad range of health measures as our study did, which may explain the discrepancy in results.…”

“…Health measures were selected because they encompass a broad range of health aspects. Moreover, the questions on self-rated health (29), functional limitations (11,17), medication use (29), and the presence of chronic diseases (30) as well as tests of lung function (31) and physical performance (32) have been shown to be associated with mortality in older adults.…”

“…Third, many studies have used samples that were selective with respect to sex (1), education (10), health (1,12), or degree of urbanization (8,(15)(16)(17). The use of selective samples may limit the generalizability of the conclusions drawn from the results.…”

Two-year follow-up study of elderly residents in S. Paulo, Brazil: methodology and preliminary results

“…Yet there are several other studies based on non-populational samples 13,14,16,18,29,32 , or based on populational samples that were not originally designed to assess only elderly people 3,15,20,30 .…”

Análisis de las principales variables determinantes de la evolución de la mortalidad por demencias en Andalucía

“…Desde hace unos años se están creando registros de demencias que en un futuro suministraran información muy valiosa sobre estas enfermedades en España 7,8 . Pero desde la perspectiva poblacional existen pocos indicadores para conocer la prevalencia y tendencia de este importante problema de salud pública y aunque la mortalidad no es un buen indicador para conocer qué ocurre en la población con las enfermedades crónicas degenerativas que son altamente prevalentes pero producen pocas defunciones, en el caso de las demencias, por su origen orgánico y el deterioro físico que producen, pueden ser consideradas causas importantes de defunción 9 . Las demencias irreversibles en las que se incluye la enfermedad de Alzheimer, fueron la octava causa de mortalidad en 2003 y la séptima en los años del 2004 al 2006 en los Estados Unidos 10,11 .…”