Older people who develop dementia have higher rates of hospitalizations for medical illnesses than do those without dementia. In addition, those with dementia are at greater risk for several conditions that could be treated in the ambulatory setting, potentially reducing hospitalizations.

A total of 494 patients developed dementia during an average follow-up of 8 years; of those, 427 (86%) were hospitalized. In comparison, 2,525 individuals remained dementia-free during 10 years of follow-up; of those, 1,478 (59%) were hospitalized. Forty percent of those with dementia had at least one admission for an ambulatory care–sensitive condition (ACSC), compared with 17% of the dementia-free group. ASCSs were considered to be preventable with proactive outpatient care.

The findings come from a population-based, longitudinal study of aging and the incidence of and risk factors for dementia, involving more than 3,500 members of a large integrated health care delivery system. The study results were published in the Jan. 11 issue of JAMA (2012;307:165-72).

"Three ACSCs – pneumonia, [congestive heart failure], and [urinary tract infections] – accounted for two-thirds of all potentially preventable admissions among persons with dementia. Knowledge of the ACSCs most likely to lead to hospitalization is important, as this information may help clinicians focus their differential diagnostic considerations and thereby permit proactive, early management for these conditions among patients with dementia," wrote Dr. Elizabeth A. Phelan and her coinvestigators.

"Early detection and outpatient management of acute illness when it is still in its early phases might minimize the need for hospitalization for these conditions and help health care organizations reduce their rates of ACSC admissions and associated costs," wrote Dr. Phelan of the division of gerontology and geriatric medicine at the University of Washington in Seattle.

Participants were from the Adult Changes in Thought (ACT) cohort, a population-based, longitudinal study of aging and the incidence of and risk factors for dementia that began in 1994. The study involved more than 3,019 members of Group Health Cooperative, a large integrated health care delivery system. Eligible individuals were aged 65 years or older, cognitively intact, and not residing in a nursing home at the time of enrollment in the cohort (mean age at inception was 75 years). Participants have been followed up every 2 years with an in-person interview that includes dementia and health status assessment.

A biennial examination was conducted to identify cases of incident dementia. Participants who scored less than 86 on the Cognitive Abilities Screening Instrument (CASI) or had symptoms suggesting possible new onset of cognitive impairment underwent a standardized dementia diagnostic evaluation consisting of an examination by a study physician and detailed neuropsychological testing.

The results were presented at a consensus conference attended by study physicians, a neuropsychologist, a research nurse, and interviewers, and a consensus diagnosis was recorded based on standardized criteria (Diagnostic and Statistical Manual of Mental Disorders–IV and Neurological and Communicative Disorders and Stroke–Alzheimer’s Disease and Related Disorders Association criteria). Participants with incident dementia underwent one annual follow-up examination for verification of dementia status and dementia type.

The researchers used a retrospective, longitudinal cohort design to assess inpatient admission rates. ACT participants were eligible for these analyses if they did not have dementia at the baseline ACT visit; had completed at least one ACT follow-up visit (to assess for incident dementia); and were enrolled in GHC at the time of a follow-up visit (to ensure availability of hospitalization data).