Journal of General Internal Medicine

, Volume 13, Issue 4, pp 234–242 | Cite as

Does delirium contribute to poor hospital outcomes?

A three-site epidemiologic study
  • Sharon K. Inouye
  • Julia T. Rushing
  • Marquis D. Foreman
  • Robert M. Palmer
  • Peter Pompei
Original Articles

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 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    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.Google Scholar
  2. 2.
    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.PubMedCrossRefGoogle Scholar
  3. 3.
    Marcantonio ER, Goldman L, Mangione CM, et al. A clinical prediction rule for delirium after elective noncardiac surgery. JAMA. 1994;271:134–9.PubMedCrossRefGoogle Scholar
  4. 4.
    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.PubMedGoogle Scholar
  5. 5.
    Murray AM, Levkoff SE, Wetle TT, et al. Acute delirium and functional decline in the hospitalized elderly patient. J Gerontol. 1993;48:M181–6.PubMedGoogle Scholar
  6. 6.
    Francis J, Kapoor WN. Prognosis after hospital discharge of older medical patients with delirium. J Am Geriatr Soc. 1992;40:601–6.PubMedGoogle Scholar
  7. 7.
    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.PubMedCrossRefGoogle Scholar
  8. 8.
    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.Google Scholar
  9. 9.
    Francis J, Martin D, Kapoor WN. A prospective study of delirium in hospitalized elderly. JAMA. 1990;263:1097–101.PubMedCrossRefGoogle Scholar
  10. 10.
    Rockwood K. Delays in the discharge of elderly patients. J Clin Epidemiol. 1990;43:971–5.PubMedCrossRefGoogle Scholar
  11. 11.
    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.PubMedGoogle Scholar
  12. 12.
    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.PubMedCrossRefGoogle Scholar
  13. 13.
    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.PubMedCrossRefGoogle Scholar
  14. 14.
    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.PubMedGoogle Scholar
  15. 15.
    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.PubMedGoogle Scholar
  16. 16.
    Thomas RI, Cameron DJ, Fahs MC. A prospective study of delirium and prolonged hospital stay: exploratory study. Arch Gen Psychiatry. 1988;45:937–40.PubMedGoogle Scholar
  17. 17.
    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.PubMedGoogle Scholar
  18. 18.
    Rabins PV, Folstein MF. Delirium and dementia: diagnostic criteria and fatality rates. Br J Psychiatry. 1982;140:149–53.PubMedCrossRefGoogle Scholar
  19. 19.
    Hodkinson HM. Mental impairment in the elderly. J R Coll Physicians Lond. 1973;7:305.PubMedGoogle Scholar
  20. 20.
    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.PubMedGoogle Scholar
  21. 21.
    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.PubMedGoogle Scholar
  22. 22.
    Lawton MP, Brady EM. Assessment of older people: self-maintaining instrumental activities of daily living. Gerontologist. 1969;9:179–86.PubMedGoogle Scholar
  23. 23.
    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.PubMedCrossRefGoogle Scholar
  24. 24.
    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.PubMedGoogle Scholar
  25. 25.
    Pompei P, Foreman M, Cassel CK, Alessi C, Cox D. Detecting delirium among hospitalized older patients. Arch Intern Med. 1995;155:301–7.PubMedCrossRefGoogle Scholar
  26. 26.
    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.PubMedCrossRefGoogle Scholar
  27. 27.
    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.PubMedCrossRefGoogle Scholar
  28. 28.
    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.PubMedCrossRefGoogle Scholar
  29. 29.
    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.Google Scholar
  30. 30.
    Knaus WA, Draper EA, Wagner DP, Zimmerman JE. APACHE II: A severity of disease classification system. Crit Care Med. 1985;13:818–29.PubMedCrossRefGoogle Scholar
  31. 31.
    Gent M, Sackett DL. The qualification and disqualification of patients and events in long-term cardiovascular clinical trials. Thromb Haemost. 1979;41:123–34.PubMedGoogle Scholar
  32. 32.
    Agresti A. Categorical Data Analysis. New York, NY: John Wiley and Sons; 1990.Google Scholar
  33. 33.
    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.Google Scholar
  34. 34.
    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.PubMedCrossRefGoogle Scholar
  35. 35.
    Little JAR, Rubin DB. Statistical Analysis with Missing Data. New York, NY: John Wiley and Sons; 1987.Google Scholar
  36. 36.
    Schor JD, Levkoff SE, Lipsitz LA, et al. Risk factors for delirium in hospitalized elderly. JAMA. 1992;267:827–31.PubMedCrossRefGoogle Scholar
  37. 37.
    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.PubMedGoogle Scholar
  38. 38.
    Rockwood K. Acute confusion in elderly medical patients. J Am Geriatr Soc. 1989;37:150–4.PubMedGoogle Scholar
  39. 39.
    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.PubMedGoogle Scholar
  40. 40.
    Erkinjuntti T, Wikstrom J, Palo J, Autio L. Dementia among medical inpatients: evaluation of 2000 consecutive admissions. Arch Intern Med. 1986;146:1923–6.PubMedCrossRefGoogle Scholar
  41. 41.
    Rockwood K. The occurrence and duration of symptoms in elderly patients with delirium. J Gerontol Med Sci. 1993;48:M162–6.Google Scholar
  42. 42.
    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.PubMedGoogle Scholar
  43. 43.
    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.PubMedGoogle Scholar
  44. 44.
    Gillick MR, Serrell NA, Gillick LS. Adverse consequences of hospitalization in the elderly. Soc Sci Med. 1982;16:1033–38.PubMedCrossRefGoogle Scholar
  45. 45.
    Lipowski AJ. Delirium: Acute Confusional States. Oxford, UK: Oxford University Press; 1990.Google Scholar
  46. 46.
    Francis J, Kapoor WN. Delirium in hospitalized elderly. J Gen Intern Med. 1990;5:65–79.PubMedCrossRefGoogle Scholar
  47. 47.
    Levkoff SE, Basdine RW, Wetle T. Acute confusional states (delirium) in the hospitalized elderly. Ann Rev Gerontol Geriatr. 1986;6:1–26.Google Scholar
  48. 48.
    Liston EH. Delirium in the aged. Psychiatr Clin North Am. 1982;5:49–66.PubMedGoogle Scholar

Copyright information

© Society of General Internal Medicine 1998

Authors and Affiliations

  • Sharon K. Inouye
    • 1
  • Julia T. Rushing
    • 2
  • Marquis D. Foreman
    • 3
  • Robert M. Palmer
    • 5
  • Peter Pompei
    • 4
  1. 1.Received from the Department of Internal MedicineYale University School of MedicineNew Haven
  2. 2.Department of Public Health SciencesBowman Gray School of Medicine of Wake Forest UniversityWinston-Salem
  3. 3.Department of NursingUniversity of Chicago Hospitals
  4. 4.Department of MedicineUniversity of Chicago Hospitals
  5. 5.the Department of MedicineUniversity Hospitals of Cleveland

Personalised recommendations