Cognitive Decline in High-Functioning Older Persons Is Associated with an Increased Risk of Hospitalization
Published in: Journal of the American Geriatrics Society, v. 52, no. 9, Sep. 2004, p. 1456-1462
Posted on RAND.org on January 01, 2004
OBJECTIVES: To examine hospital use for patients with evidence of cognitive decline indicative of early cognitive impairment. DESIGN: Medicare Part A hospital utilization data were linked to data from the MacArthur Research Network on Successful Aging Community Study to examine the association between baseline cognition and decline in cognitive function over a 3-year period and any hospitalization over that same period. SETTING: New Haven, Connecticut, and East Boston, Massachusetts. PARTICIPANTS: Subjects (N=598) were from two sites of the MacArthur Research Network on Successful Aging Community Study, a 7-year cohort study of community-dwelling older persons with high physical and cognitive functioning. MEASUREMENTS: Multivariate logistic regression was used to determine the association between any hospitalization over 3 years (1988-91) as the outcome variable and baseline cognitive function and decline in cognition over 3 years as primary predictor variables. Decline was based upon repeated (1988 and 1991) measures of delayed verbal recall and the Short Portable Mental Status Questionnaire (SPMSQ). RESULTS: Of 598 subjects, 48 died between 1988 and 1991. No baseline (1988) delayed recall scores or change in recall scores (1988-91) were associated with hospitalization. Although 48.2% declined on verbal memory scores, decline was not associated with risk of hospitalization. Of 494 subjects with complete 3-year data, 31.2% declined at least one point on the SPMSQ, and 4.7% declined more than two points. Among individuals aged 75 and older at baseline, the adjusted odds ratio for hospitalization for those who declined more than 2 points compared with those who declined less was 7.8 (95% confidence interval=2.0-30.8). CONCLUSION: Although specific memory tests were not associated with hospitalization, high-functioning older persons who experienced decline in overall cognitive function were more likely to be hospitalized. Variation in baseline cognitive function in this high-functioning cohort did not affect hospitalization, but additional research is needed to evaluate associations with other healthcare costs.