Does delirium contribute to poor hospital outcomes? : A three-site epidemiologic study

Short-stay hospitalization in older patients is frequently associated with a loss of function, which can lead to a need for postdischarge assistance and longer-term institutionalization. Because little is known about this adverse outcome of hospitalization, this study was conducted to (1) determine the discharge and 3-month postdischarge functional outcomes for a large cohort of older persons hospitalized for medical illness, (2) determine the extent to which patients were able to recover to preadmission levels of functioning after hospital discharge, and (3) identify the patient factors associated with an increased risk of developing disability associated with acute illness and hospitalization. A total of 1279 community-dwelling patients, aged 70 years and older, hospitalized for acute medical illness were enrolled in this multicenter, prospective cohort study. Functional measurements obtained at discharge (Activities of Daily Living) and at 3 months after discharge (Activities of Daily Living and Instrumental Activities of Daily Living) were compared with a preadmission baseline level of functioning to document loss and recovery of functioning. At discharge, 59% of the study population reported no change, 10% improved, and 31% declined in Activities of Daily Living when compared with the preadmission baseline. At the 3-month follow-up, 51% of the original study population, for whom postdischarge data were available (n=1206), were found to have died (11%) or to report new Activities of Daily Living and/or Instrumental Activities of Daily Living disabilities (40%) when compared with the preadmission baseline. Among survivors, 19% reported a new Activities of Daily Living and 40% reported a new Instrumental Activities of Daily Living disability at follow-up. The 3-month outcomes were the result of the loss of function during the index hospitalization, the failure of many patients to recover after discharge, and the development of new postdischarge disabilities. Patients at greatest risk of adverse functional outcomes at follow-up were older, had preadmission Instrumental Activities of Daily Living disabilities and lower mental status scores on admission, and had been rehospitalized. This study documents a high incidence of functional decline after hospitalization for acute medial illness. Although there are several potential explanations for these findings, this study suggests a need to reexamine current inpatient and postdischarge practices that might influence the functioning of older patients.

To develop and validate a clinical prediction rule for postoperative delirium using data available to clinicians preoperatively. Prospective cohort study. General surgery, orthopedic surgery, and gynecology services at Brigham and Women's Hospital, Boston, Mass. Consenting patients older than 50 years admitted for major elective noncardiac surgery between November 1, 1990, and March 15, 1992 (N = 1341). All patients underwent preoperative evaluations, including a medical history, physical examination, laboratory tests, and assessments of physical and cognitive function using the Specific Activity Scale and the Telephone Interview for Cognitive Status. Postoperative delirium was diagnosed using the Confusion Assessment Method or using data from the medical record and the hospital's nursing intensity index. Patients were followed up for the duration of hospitalization to determine major complication rates, length of stay, and discharge disposition. Postoperative delirium occurred in 117 (9%) of the 1341 patients studied. Independent correlates included age 70 years or older; self-reported alcohol abuse; poor cognitive status; poor functional status; markedly abnormal preoperative serum sodium, potassium, or glucose level; noncardiac thoracic surgery; and aortic aneurysm surgery. Using these seven preoperative factors, a simple predictive rule was developed. In an independent population, the rule stratified patients into groups with low (2%), medium (8%, 13%), and high (50%) rates of postoperative delirium. Patients who developed delirium had higher rates of major complications, longer lengths of stay, and higher rates of discharge to long-term care or rehabilitative facilities. Using data available preoperatively, clinicians can stratify patients into risk groups for the development of delirium. Since delirium is associated with a variety of adverse outcomes, patients with substantial risk for this complication could be candidates for interventions to reduce the incidence of postoperative delirium and potentially improve overall surgical outcomes.

Delirium, with occurrence rates from 14% to 56%, associated mortality rates from 10% to 65%, and excess annual health care expenditures from $1 to $2 billion, poses a common and serious problem for hospitalized elderly patients. Delirium is often unrecognized or misdiagnosed by physicians caring for elderly patients. Cognitive testing is rarely done as part of the admission evaluation of elderly hospitalized patients. Specific diagnosis has been difficult, since diagnostic criteria and instruments are still being developed. The etiology of delirium is complex and multifactorial, and both predisposing (host vulnerability) and precipitating factors must be considered. The recommended approach to the evaluation of delirium is empiric, in the absence of objective efficacy data. The cornerstone of evaluation includes a careful history, physical examination, and review of the medication list--since medications are the most common reversible cause of delirium. Research is needed to establish a cost-effective approach and to clarify the role of further testing, such as cerebrospinal fluid examination, brain imaging, and electroencephalography. This article is intended to heighten the awareness of clinicians as well as to stimulate research to address this important, neglected problem for elderly hospitalized patients.