Does delirium contribute to poor hospital outcomes?
A three-site epidemiologic study
Cite this article as: Inouye, S.K., Rushing, J.T., Foreman, M.D. et al. J GEN INTERN MED (1998) 13: 234. doi:10.1046/j.1525-1497.1998.00073.x Abstract OBJECTIVE: To determine the independent contribution of admission delirium to hospital outcomes including mortality, institutionalization, and functional decline. DESIGN: Three prospective cohort studies. SETTING: Three university-affiliated teaching hospitals. PATIENTS: Consecutive samples of 727 patients, aged 65 years and older. MEASUREMENTS AND MAIN RESULTS: Delirum was present at admission in 88 (12%) of 727 patients. The main outcome measures at hospital discharge and 3-month follow-up were death, new nursing home placement, death or new nursing home placement, and functional decline. At hospital discharge, new nursing home placement occurred in 60 (9%) of 692 patients, and the adjusted odds ratio (OR) for delirium, controlling for baseline covariates of age, gender, dementia, APACHE II score, and functional measures, was 3.0, (95% confidence interval [CI] 1.4, 6.2). Death or new nursing home placement occurred in 95 (13%) of 727 patients (adjusted OR for delirium 2.1, 95% CI 1.1, 4.0). The findings were replicated across all sites. The associations between delirium and death alone (in 35 [5%] of 727 patients) and between delirium and length of stay were not statistically significant. At 3-month follow-up, new nursing home placement occurred in 77 (13%) of 600 patients (adjusted OR for delirium 3.0; 95% CI 1.5, 6.0). Death or new nursing home placement occurred in 165 (25%) of 663 patients (adjusted OR for delirium 2.6; 95% CI 1.4, 4.5). The findings were replicated across all sites. For death alone (in 98 [14%] of 680 patients), the adjusted OR for delirium was 1.6 (95% CI 0.8, 3.2). Delirium was a significant predictor of functional decline at both hospital discharge (adjusted OR 3.0; 95% CI 1.6, 5.8) and follow-up (adjusted OR 2.7; 95% CI 1.4, 5.2). CONCLUSIONS: Delirium is an important independent prognostic determinant of hospital outcomes including new nursing home placement, death or new nursing home placement, and functional decline—even after controlling for age, gender, dementia, illness severity, and functional status. Thus, delirium should be considered as a prognostic variable in case-mix adjustment systems and in studies examining hospital outcomes in older persons. Key words delirium acute confusional state risk adjustment geriatrics hospital outcomes
Supported in part by grants from the National Institute on Aging (R01AG12551), the John A. Hartford Foundation (883453G), the Retirement Research Foundation (91-66 and 94-71), and the Commonwealth Fund (94-90). Dr. Inouye was a recipient of Academic Award K08AG00524 from the National Institute on Aging during this study.
Program Resources Department, American Association of Retired Persons (AARP) and the Administration on Aging (AoA), U.S. Department of Health and Human Services. A Profile of Older Americans: 1995. Washington, DC: American Association of Retired Persons; 1995.
Inouye SK. The dilemma of delirium: clinical and research controversies regarding diagnosis and evaluation of delirium in hospitalized elderly medical patients. Am J Med. 1994;97:278–88.
Marcantonio ER, Goldman L, Mangione CM, et al. A clinical prediction rule for delirium after elective noncardiac surgery. JAMA. 1994;271:134–9.
Pompei P, Foreman M, Rudberg MA, Inouye SK, Braund V, Cassel CK. Delirium in hospitalized older persons: outcome and predictors. J Am Geriatr Soc. 1994;42:809–15.
Murray AM, Levkoff SE, Wetle TT, et al. Acute delirium and functional decline in the hospitalized elderly patient. J Gerontol. 1993;48:M181–6.
Francis J, Kapoor WN. Prognosis after hospital discharge of older medical patients with delirium. J Am Geriatr Soc. 1992;40:601–6.
Levkoff SE, Evans DA, Liptzin B, et al. Delirium: the occurrence and persistence of symptoms among elderly hospitalized patients. Arch Intern Med. 1992;152:334–40.
Brannstron B, Gustafson Y, Norberg A, Winblad B. ADL performance and dependency on nursing care in patients with hip fractures and acute confusion in a task allocation care system. Scand J Caring Sci. 1991;5:3–11.
Francis J, Martin D, Kapoor WN. A prospective study of delirium in hospitalized elderly. JAMA. 1990;263:1097–101.
Rockwood K. Delays in the discharge of elderly patients. J Clin Epidemiol. 1990;43:971–5.
Koponen H, Stenback U, Mattila E, Soininen H, Reinikainen K, Riekkinen PJ. Delirium among elderly persons admitted to a psychiatric hospital: clinical course during the acute stage and one-year follow-up. Acta Psychiatr Scand. 1989;79:579–85.
Magaziner J, Simonsick EM, Kashner M, Hebel JR, Kenzora JE. Survival experience of aged hip fracture patients. Am J Public Health. 1989;79:274–8.
Rogers MP, Liang MH, Daltroy LH, et al. Delirium after elective orthopedic surgery: risk factors and natural history. Int J Psychiatry Med. 1989;19:109–21.
Gustafson Y, Berggren D, Brannstron B, et al. Acute confusional states in elderly patients treated for femoral neck fracture. J Am Geriatr Soc. 1988;36:525–30.
Levkoff SE, Safran C, Cleary PD, Gallop J, Phillips RS. Identification of factors associated with the diagnosis of delirium in elderly hospitalized patients. J Am Geriatr Soc. 1988;36:1099–104.
Thomas RI, Cameron DJ, Fahs MC. A prospective study of delirium and prolonged hospital stay: exploratory study. Arch Gen Psychiatry. 1988;45:937–40.
Fields SD, MacKenzie CR, Charlson ME, Sax FL. Cognitive impairment: can it predict the course of hospitalized patients? J Am Geriatr Soc. 1986;34:579–85.
Rabins PV, Folstein MF. Delirium and dementia: diagnostic criteria and fatality rates. Br J Psychiatry. 1982;140:149–53.
Hodkinson HM. Mental impairment in the elderly. J R Coll Physicians Lond. 1973;7:305.
Margitic SE, Inouye SK, Thomas JL, Cassell CK, Regenstreif DI, Kowal J. Hospital Outcomes Project for the Elderly (HOPE): rationale and design for a prospective pooled analysis. J Am Geriatr Soc. 1993;41:258–67.
Katz S, Ford AB, Moskowitz RW, Jackson BA, Jaffe MW. Studies of illness in the aged: the index of ADL, a standardized measure of biological and psychosocial function. JAMA. 1963;185:914–9.
Lawton MP, Brady EM. Assessment of older people: self-maintaining instrumental activities of daily living. Gerontologist. 1969;9:179–86.
Folstein MF, Folstein SE, McHugh PR. The Folstein Mini-Mental State Examination: a practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12:189–98.
Inouye SK, vanDyck CH, Alessi CA, Balkin S, Siegal AP, Horwitz RI. Clarifying confusion: the Confusion Assessment Method; a new method for detection of delirium. Ann Intern Med. 1990;113:941–8.
Pompei P, Foreman M, Cassel CK, Alessi C, Cox D. Detecting delirium among hospitalized older patients. Arch Intern Med. 1995;155:301–7.
Inouye SK, Wagner DR, Acampora D, et al. A predictive index for functional decline in hospitalized elderly medical patients. J Gen Intern Med. 1993;8:645–52.
Sager MA, Franke T, Inouye SK, et al. Functional outcomes of acute medical illness and hospitalization in older persons. Arch Intern Med. 1996;156:645–52.
Landefeld CS, Palmer RM, Kresevic DM, Fortinsky RH, Kowal J. A randomized trial of care in a hospital medical unit especially designed to improve the functional outcomes of acutely ill older patients. N Engl J Med. 1995;332:1338–44.
Rudberg MA, Sager MA, Zhang J. Risk factors for nursing home use after hospitalization for medical illness. J Gerontol Med Sci. 1996;51A:M189–94.
Knaus WA, Draper EA, Wagner DP, Zimmerman JE. APACHE II: A severity of disease classification system. Crit Care Med. 1985;13:818–29.
Gent M, Sackett DL. The qualification and disqualification of patients and events in long-term cardiovascular clinical trials. Thromb Haemost. 1979;41:123–34.
Agresti A. Categorical Data Analysis. New York, NY: John Wiley and Sons; 1990.
Breslow NE, Day NE. Statistical Methods in Cancer Research, Vol 1: The Analysis of Case-Control Studies. Lyon, France: International Agency for Research on Cancer; 1980.
Dudley RA, Harrell FE, Smith LR, et al. Comparison of analytic models for estimating the effect of clinical factors on the cost of coronary artery bypass graft surgery. J Clin Epidemiol. 1993;46:261–71.
Little JAR, Rubin DB. Statistical Analysis with Missing Data. New York, NY: John Wiley and Sons; 1987.
Schor JD, Levkoff SE, Lipsitz LA, et al. Risk factors for delirium in hospitalized elderly. JAMA. 1992;267:827–31.
Johnson JC, Gottlieb JL, Sullivan E, et al. Using DSM-III criteria to diagnose delirium in elderly general medical patients. J Gerontol. 1990;45:M113–9.
Rockwood K. Acute confusion in elderly medical patients. J Am Geriatr Soc. 1989;37:150–4.
Cameron DJ, Thomas RI, Mulvihill M, et al. Delirium: a test of the Diagnostic and Statistical Manual III criteria on medical inpatients. J Am Geriatr Soc. 1987;35:1007–10.
Erkinjuntti T, Wikstrom J, Palo J, Autio L. Dementia among medical inpatients: evaluation of 2000 consecutive admissions. Arch Intern Med. 1986;146:1923–6.
Rockwood K. The occurrence and duration of symptoms in elderly patients with delirium. J Gerontol Med Sci. 1993;48:M162–6.
Narain P, Rubenstein LZ, Wieland GD, et al. Predictors of immediate and 6-month outcomes in hospitalized elderly patients: the importance of functional status. J Am Geriatr Soc. 1988;36:775–83.
Winograd CH, Gerety MB, Chung M, Goldstein MK, Dominguez F, Vallone R. Screening for frailty: criteria and predictors of outcomes. J Am Geriatr Soc. 1991;39:778–84.
Gillick MR, Serrell NA, Gillick LS. Adverse consequences of hospitalization in the elderly. Soc Sci Med. 1982;16:1033–38.
Lipowski AJ. Delirium: Acute Confusional States. Oxford, UK: Oxford University Press; 1990.
Francis J, Kapoor WN. Delirium in hospitalized elderly. J Gen Intern Med. 1990;5:65–79.
Levkoff SE, Basdine RW, Wetle T. Acute confusional states (delirium) in the hospitalized elderly. Ann Rev Gerontol Geriatr. 1986;6:1–26.
Liston EH. Delirium in the aged. Psychiatr Clin North Am. 1982;5:49–66.
PubMed Copyright information
© Society of General Internal Medicine 1998