Person:

Inouye, Sharon

OBJECTIVES: To compare performance characteristics of the Confusion Assessment Method (CAM) algorithm for screening and delirium diagnosis with criteria for delirium from the International Classification of Diseases, Tenth Revision (ICD-10) and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) in high-risk individuals. DESIGN: Prospective cohort study. SETTING: Academic geriatric hospital. PARTICIPANTS: One hundred two individuals aged 80 to 100 hospitalized for acute medical illness. MEASUREMENTS: Complete CAM instrument (nine items), scored using the four-item CAM diagnostic algorithm. Criterion standard classification of delirium was rated independently according to expert consensus based on DSM-IV and ICD-10 criteria for delirium. RESULTS: In 79 hospitalized participants, the CAM performed well for delirium screening (delirium prevalence of 24% according to DSM-IV and 14% according to ICD-10). Of all CAM features, acute onset and fluctuating course are most important for diagnosis (area under the receiver operating characteristic curve (AUC) = 0.92 in DSM-IV and 0.83 in ICD-10). The CAM diagnostic algorithm had a sensitivity of 0.74, a specificity of 1.0, and an AUC of 0.88 compared with the DSM-IV reference standard and a sensitivity of 0.82, a specificity of 0.91, and an AUC of 0.85 compared with the ICD-10. Compared with the ICD-10, adding psychomotor change to the CAM algorithm improved specificity to 97%, but sensitivity fell to 55% (AUC = 0.96). Applying psychomotor change sequentially only to the group that the CAM algorithm identified as having no delirium improved sensitivity to 91% with specificity of 85% (AUC = 0.95). CONCLUSION: Although the CAM diagnostic algorithm performed well against a DSM-IV reference standard, adding psychomotor change to the CAM algorithm improved specificity and diagnostic value against ICD-10 criteria overall in older adults with dementia and improved sensitivity and screening performance when applied sequentially in CAM-negative individuals.

Introduction. Delirium, or acute confusional state, is a common and serious occurrence among hospitalized older persons. Current estimates suggest that delirium complicates hospital stays for more than 2.3 million older persons each year, involving more than 17.5 million hospital days and accounting for more than $4 billion (1994 dollars) of Medicare expenditures. A 40% reduction was recently reported in the risk for delirium among hospitalized older persons receiving a multicomponent targeted risk factor intervention (MTI) strategy to prevent delirium, compared with subjects receiving usual hospital care. 1 Before recommending that this preventive strategy be implemented in clinical practice, however, the cost implications must be thoroughly examined as well.

Methods. The present analysis performs net cost evaluations of the MTI for the prevention of delirium among hospitalized patients. Hospital charge and cost-to-charge ratio data are linked to a database of 852 subjects, who were treated with MTI or usual care. Multivariable regression methods were used to help isolate the impact of MTI on hospital costs. These results were then combined with our earlier work on the impact of the MTI on delirium prevention to assess the cost effectiveness of this intervention.

Results. The MTI significantly reduced nonintervention costs among subjects at intermediate risk for developing delirium, but not among subjects at high risk. When MTI intervention costs were included, MTI had no significant effect on overall health care costs in the intermediate risk cohort, but raised overall costs in the high risk group.

Conclusions. Because the MTI prevented delirium in the intermediate risk group without raising costs, the conclusion reached is that it is a cost effective treatment option for patients at intermediate risk for developing delirium. In contrast, the results suggest that the MTI is not cost effective for subjects at high risk.

Background: Delirium has been associated with more rapid cognitive decline. However, it is unknown whether increased delirium severity is associated with a higher rate of long-term cognitive decline. Objective: To evaluate delirium severity and the presence and rate of cognitive decline over 36 months following surgery. Methods: We examined patients from the Successful Aging after Elective Surgery Study, who were age ≥70 years undergoing major elective surgery (N=560). Delirium severity was determined by the peak Confusion Assessment Method-Severity (CAM-S) score for each patient’s hospitalization and grouped based on the sample distribution: scores of 0-2, 3-7, and 8-19. A neuropsychological composite, General Cognitive Performance (GCP), and proxy-reported Informant Questionnaire for Cognitive Decline (IQCODE) were used to examine cognitive outcomes following surgery at 0, 1, 2 months, and every 6 months for up to 3 years. Results: No significant cognitive decline was observed for patients with peak CAM-S scores 0-2 (-0.17 GCP units/year, 95% confidence interval [CI] -0.35, 0.01). GCP scores decreased significantly in the group with peak CAM-S scores 3-7 (-0.30 GCP units/year, 95% CI-0.51, -0.09), and decreased almost three times faster in the highest delirium severity group (peak CAM-S scores 8-19; -0.82 GCP units/year, 95% CI -1.28, -0.37). A similar association was found for delirium severity and the proportion of patients who developed IQCODE impairment over time.
Conclusion: Patients with the highest delirium severity experienced the greatest rate of cognitive decline, which exceeds the rate previously observed for patients with dementia, on serial neuropsychological testing administered over 3 years, with a dose-response relationship between delirium severity and long-term cognitive decline.

Objective: To determine the impact of dementia on the outcomes of intensive care unit (ICU) care and use of ICU interventions among older patients. Design: Prospective observational cohort study. Setting: Urban university teaching hospital. Patients: Patients were 395 patients age >=65 consecutively admitted to a medical ICU. Interventions: None. Measurements and Main Results: Dementia was determined by a previously validated proxy measure, the Modified Blessed Dementia Rating Scale. We chose cut points to focus on patients with moderate-severe dementia at baseline. Our primary outcomes included length of mechanical ventilation and ICU and hospital length of stay. Secondary outcomes included ICU readmission, changes in code status, discharge location, mortality, and use of ICU interventions. Medical record abstraction was performed to determine the rates of ICU outcomes, use of ICU interventions, and potential confounders. Our study documented a prevalence of moderate-severe dementia of 17% in patients age >=65 admitted to the ICU. Patients with dementia were significantly older (80 vs. 76), more likely to be female (65% vs. 52%), and more likely to be admitted from a nursing home (46% vs. 11%). Patients with dementia had significantly higher Acute Physiology and Chronic Health Evaluation II scores on admission to the ICU (25 vs. 23). Patients with dementia were more likely to have their code status changed to less aggressive in the ICU (24% vs. 14%). There was no significant difference in readmission to the ICU, discharge location, ICU or hospital mortality rate, or use of ICU interventions between patients with and without dementia. Conclusions: Our study documents no difference in outcomes from ICU care in older patients with and without dementia. There was no increased short-term mortality rate in older patients with dementia compared with those without dementia after admission to the ICU. Presumptions that outcomes from critical care are less favorable in patients with dementia should not drive treatment decisions in the ICU.

This study provides an overview of racial differences in etiology and prevalence of dementia. Preliminary findings indicate that the clinical and molecular etiologies of dementia differ between races. African Americans have a higher prevalence of vascular dementia and a lower prevalence of Parkinsonian dementia than do Caucasians. The genetic etiologies of Alzheimer's-type dementia appear to differ between African Americans and Caucasians. The variations in dementia etiologies and in cognitive testing accuracy between races suggests the urgent need to develop racially appropriate cognitive assessment methods and to develop preventive and treatment etiologies differently according to racial background of individual patients.