Cognitive function and acute care utilization.

OBJECTIVES: Little is known about variation in cognitive function across the aged population, or how use and costs of health care vary with cognitive impairment. This study was designed to create a typology of cognitive function in a nationally representative sample, and evaluate acute care use in relation to cognitive function, holding constant confounding factors. By including proxy assessments of cognitive function, this is the first study to include individuals unable to respond themselves.

METHODS: We analyzed the baseline year of the Asset and Health Dynamics Among the Oldest Old (AHEAD) survey, sponsored by the National Institute on Aging, to create three levels of cognitive function, using direct measures for self-respondents (n = 6,651) and proxy evaluations for the others (n = 792). We used a two-part model to predict the likelihood of using various health services and to evaluate intensity of care among users.

RESULTS: Sixteen percent, 64%, and 20% of the sample fell into the low, moderate, and high cognitive function groups, respectively, that differed significantly on almost all demographic and health status measures, and some utilization measures. Controlling for other health and functional status measures, lower cognitive function had a significant and negative effect on outpatient services, but did not affect hospital use directly.

DISCUSSION: Lower cognitive function may be a barrier to outpatient care, but these analyses should be repeated using administrative use and cost data.