The Prevalence of Dementia and Cognitive Impairment in Hospitals

Abstract

Background: The care of elderly patients with comorbid dementia poses an increasing challenge in the acute inpatient setting, yet there remains a lack of representative studies on the prevalence and distribution of dementia in general hospitals.

Methods: We conducted a cross-sectional study of patients aged 65 and older in randomly selected general hospitals in southern Germany. Patients were excluded if they were in an intensive care unit or isolation unit or if they were on specialized wards for psychiatry, neurology, or geriatric medicine. The findings are derived from patient interviews, neuropsychological testing, standardized rating scales, questioning of nursing staff, and the patients' medical records.

Results: 1469 patients on 172 inpatient wards of 33 hospitals were studied. 40.0% of them (95% confidence interval, [36.2; 43.7]) had at least mild cognitive impairment. The point-prevalence of dementing illnesses was 18.4% [16.3; 20.7]. Delirium, most often on the basis of dementia, was present in 5.1% [3.9; 6.7]. 60.0% had no cognitive impairment. Dementia was more common among patients of very advanced age, those who were dependent on nursing care, those who lived in old-age or nursing homes, and those with a low level of education. Among patients with dementia, only 36.7% had a documented diagnosis of dementia in the medical record. Patients with dementia were treated more often for dehydration, electrolyte disturbances, urinary tract infections, contusions, and bone fractures, as well as for symptoms and findings of an unknown nature, and much less often for cancer or musculoskeletal diseases.

Conclusion: Two out of five elderly patients in general hospitals suffer from a cognitive disturbance. Patients with severe impairments such as dementia or delirium often need special care. Guidelines and model projects offer approaches by which the inpatient care of patients with comorbid dementia can be improved.

Figure 1

Response rate

Figure 2

Distribution of patient sample by type and severity of cognitive impairment. Information about diagnostic distribution is based on n = 1468 patients; in 1 case, diagnostic assessment not possible due to incomplete data; diagnosis of dementia according to DSM-IV criteria; diagnosis of delirium according to Confusion Assessment Method (CAM) criteria. CDR, Clinical Dementia Rating (severity of cognitive impairment)

eFigure 1

Data collection and diagnostic process Diagnosis of dementia according to DSM-IV criteria CDR, Clinical Dementia Rating CAM, Confusion Assessment Method

eFigure 2

Age- and sex-specific prevalence of dementia in the patient sample

eFigure 3

Prevalence of dementia in the general hospital versus in the population Prevalence rate in the general hospital: according to this study; age- and sex-specific prevalence rate in the elderly population: according to EuroCoDe (22) IRR, indirect standardized rate ratio

eFigure 4

Prevalence of dementia among men in the general hospital versus in the population Prevalence rate among male general hospital patients: according to this study; age-specific prevalence rate in the male elderly population: according to EuroCoDe (22) IRR, indirect standardized rate ratio

eFigure 5

Prevalence of dementia among women in the general hospital versus in the population Prevalence rate among female general hospital patients: according to this study; age-specific prevalence rate in the female elderly population: according to EuroCoDe (22) IRR, indirect standardized rate ratio