Sharon K. Inouye

Clarifying Confusion: The Confusion Assessment Method: A New Method for Detection of Delirium

OBJECTIVE To develop and validate a new standardized confusion assessment method (CAM) that enables nonpsychiatric clinicians to detect delirium quickly in high-risk settings. DESIGN Prospective validation study. SETTING Conducted in general medicine wards and in an outpatient geriatric assessment center at Yale University (site 1) and in general medicine wards at the University of Chicago (site 2). PATIENTS The study included 56 subjects, ranging in age from 65 to 98 years. At site 1, 10 patients with and 20 without delirium participated; at site 2, 16 patients with and 10 without delirium participated. MEASUREMENTS AND MAIN RESULTS An expert panel developed the CAM through a consensus building process. The CAM instrument, which can be completed in less than 5 minutes, consists of nine operationalized criteria from the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). An a priori hypothesis was established for the diagnostic value of four criteria: acute onset and fluctuating course, inattention, disorganized thinking, and altered level of consciousness. The CAM algorithm for diagnosis of delirium required the presence of both the first and the second criteria and of either the third or the fourth criterion. At both sites, the diagnoses made by the CAM were concurrently validated against the diagnoses made by psychiatrists. At sites 1 and 2 values for sensitivity were 100% and 94%, respectively; values for specificity were 95% and 90%; values for positive predictive accuracy were 91% and 94%; and values for negative predictive accuracy were 100% and 90%. The CAM algorithm had the highest predictive accuracy for all possible combinations of the nine features of delirium. The CAM was shown to have convergent agreement with four other mental status tests, including the Mini-Mental State Examination. The interobserver reliability of the CAM was high (kappa = 0.81 - 1.0). CONCLUSIONS The CAM is sensitive, specific, reliable, and easy to use for identification of delirium.

A Multicomponent Intervention to Prevent Delirium in Hospitalized Older Patients

BACKGROUND Since in hospitalized older patients delirium is associated with poor outcomes, we evaluated the effectiveness of a multicomponent strategy for the prevention of delirium. METHODS We studied 852 patients 70 years of age or older who had been admitted to the general-medicine service at a teaching hospital. Patients from one intervention unit and two usual-care units were enrolled by means of a prospective matching strategy. The intervention consisted of standardized protocols for the management of six risk factors for delirium: cognitive impairment, sleep deprivation, immobility, visual impairment, hearing impairment, and dehydration. Delirium, the primary outcome, was assessed daily until discharge. RESULTS Delirium developed in 9.9 percent of the intervention group as compared with 15.0 percent of the usual-care group, (matched odds ratio, 0.60; 95 percent confidence interval, 0.39 to 0.92). The total number of days with delirium (105 vs. 161, P=0.02) and the total number of episodes (62 vs. 90, P=0.03) were significantly lower in the intervention group. However, the severity of delirium and recurrence rates were not significantly different. The overall rate of adherence to the intervention was 87 percent, and the total number of targeted risk factors per patient was significantly reduced. Intervention was associated with significant improvement in the degree of cognitive impairment among patients with cognitive impairment at admission and a reduction in the rate of use of sleep medications among all patients. Among the other risk factors per patient there were trends toward improvement in immobility, visual impairment, and hearing impairment. CONCLUSIONS The risk-factor intervention strategy that we studied resulted in significant reductions in the number and duration of episodes of delirium in hospitalized older patients. The intervention had no significant effect on the severity of delirium or on recurrence rates; this finding suggests that primary prevention of delirium is probably the most effective treatment strategy.

Evaluation of delirium in critically ill patients: Validation of the Confusion Assessment Method for the Intensive Care Unit (cam-icu)

ObjectiveTo develop and validate an instrument for use in the intensive care unit to accurately diagnose delirium in critically ill patients who are often nonverbal because of mechanical ventilation. DesignProspective cohort study. SettingThe adult medical and coronary intensive care units of a tertiary care, university-based medical center. PatientsThirty-eight patients admitted to the intensive care units. Measurements and Main Results We designed and tested a modified version of the Confusion Assessment Method for use in intensive care unit patients and called it the CAM-ICU. Daily ratings from intensive care unit admission to hospital discharge by two study nurses and an intensivist who used the CAM-ICU were compared against the reference standard, a delirium expert who used delirium criteria from the Diagnostic and Statistical Manual of Mental Disorders (fourth edition). A total of 293 daily, paired evaluations were completed, with reference standard diagnoses of delirium in 42% and coma in 27% of all observations. To include only interactive patient evaluations and avoid repeat-observer bias for patients studied on multiple days, we used only the first-alert or lethargic comparison evaluation in each patient. Thirty-three of 38 patients (87%) developed delirium during their intensive care unit stay, mean duration of 4.2 ± 1.7 days. Excluding evaluations of comatose patients because of lack of characteristic delirium features, the two critical care study nurses and intensivist demonstrated high interrater reliability for their CAM-ICU ratings with kappa statistics of 0.84, 0.79, and 0.95, respectively (p < .001). The two nurses’ and intensivist’s sensitivities when using the CAM-ICU compared with the reference standard were 95%, 96%, and 100%, respectively, whereas their specificities were 93%, 93%, and 89%, respectively. ConclusionsThe CAM-ICU demonstrated excellent reliability and validity when used by nurses and physicians to identify delirium in intensive care unit patients. The CAM-ICU may be a useful instrument for both clinical and research purposes to monitor delirium in this challenging patient population.

Geriatric Syndromes: Clinical, Research, and Policy Implications of a Core Geriatric Concept

Geriatricians have embraced the term “geriatric syndrome,” using it extensively to highlight the unique features of common health conditions in older people. Geriatric syndromes, such as delirium, falls, incontinence, and frailty, are highly prevalent, multifactorial, and associated with substantial morbidity and poor outcomes. Nevertheless, this central geriatric concept has remained poorly defined. This article reviews criteria for defining geriatric syndromes and proposes a balanced approach of developing preliminary criteria based on peer‐reviewed evidence. Based on a review of the literature, four shared risk factors—older age, baseline cognitive impairment, baseline functional impairment, and impaired mobility—were identified across five common geriatric syndromes (pressure ulcers, incontinence, falls, functional decline, and delirium). Understanding basic mechanisms involved in geriatric syndromes will be critical to advancing research and developing targeted therapeutic options, although given the complexity of these multifactorial conditions, attempts to define relevant mechanisms will need to incorporate more‐complex models, including a focus on synergistic interactions between different risk factors. Finally, major barriers have been identified in translating research advances, such as preventive strategies of proven effectiveness for delirium and falls, into clinical practice and policy initiatives. National strategic initiatives are required to overcome barriers and to achieve clinical, research, and policy advances that will improve quality of life for older persons.

One-Year Health Care Costs Associated With Delirium in the Elderly Population

BACKGROUND While delirium has been increasingly recognized as a serious and potentially preventable condition, its long-term implications are not well understood. This study determined the total 1-year health care costs associated with delirium. METHODS Hospitalized patients aged 70 years and older who participated in a previous controlled clinical trial of a delirium prevention intervention at an academic medical center between 1995 and 1998 were followed up for 1 year after discharge. Total inflation-adjusted health care costs, calculated as either reimbursed amounts or hospital charges converted to costs, were computed by means of data from Medicare administrative files, hospital billing records, and the Connecticut Long-term Care Registry. Regression models were used to determine costs associated with delirium after adjusting for patient sociodemographic and clinical characteristics. RESULTS During the index hospitalization, 109 patients (13.0%) developed delirium while 732 did not. Patients with delirium had significantly higher unadjusted health care costs and survived fewer days. After adjusting for pertinent demographic and clinical characteristics, average costs per day survived among patients with delirium were more than 2(1/2) times the costs among patients without delirium. Total cost estimates attributable to delirium ranged from

Delirium Superimposed on Dementia: A Systematic Review

16 303 to

Cognitive trajectories after postoperative delirium.

64 421 per patient, implying that the national burden of delirium on the health care system ranges from

The Confusion Assessment Method: A Systematic Review of Current Usage

38 billion to

Delirium in the Intensive Care Unit: Occurrence and Clinical Course in Older Patients

152 billion each year. CONCLUSIONS The economic impact of delirium is substantial, rivaling the health care costs of falls and diabetes mellitus. These results highlight the need for increased efforts to mitigate this clinically significant and costly disorder.

Delirium in elderly adults: diagnosis, prevention and treatment

Delirium in a patient with preexisting dementia is a common problem that may have serious complications and poor prognostic implications. The purpose of this paper was to conduct a systematic review of the medical literature on delirium superimposed on dementia, specifically to review studies on prevalence, associated features, outcomes, and management. Areas of controversy and gaps in our knowledge of this problem are highlighted. Finally, an agenda for future research is proposed. Fourteen studies were reviewed, including seven prospective studies, three retrospective studies, two cross‐sectional studies, and two clinical trials. For the review of the literature on delirium superimposed on dementia, we searched MEDLINE from January 1966 through February 2002 for research studies with primary sources of data. Selection criteria for inclusion of articles in this study were inclusion of data on subjects with delirium superimposed on dementia, inclusion of a validated operational definition/measures of dementia and delirium, actual data on persons with delirium and dementia reported in the paper, and reporting of primary data. MEDLINE was searched using the following key search terms: delirium, acute confusion, cognitive impairment, Alzheimers disease, dementia, delirium superimposed on dementia, and elderly. The prevalence of delirium superimposed on dementia ranged from 22% to 89% of hospitalized and community populations aged 65 and older with dementia. To date, only one reported study systematically identified associated factors and interventions for delirium superimposed on dementia, but several studies examining outcomes have found that adverse events are associated with delirium in persons with dementia, including accelerated and long‐term cognitive and functional decline, need for institutionalization, rehospitalization, and increased mortality. This paper highlights the dearth of research on delirium superimposed on dementia and stresses the importance of early recognition and prevention of delirium in persons with dementia.