Delirium, characterized by confusion or a change in mental status, is a common occurrence among older adults, particularly among hospitalized seniors recovering from illness or surgical procedure.
Delirium can lead to poorer prognosis among older patients. Studies have connected delirium in adults 65 and older with hospital mortality rates of up to 33 percent and estimated health care costs of more than $182 billion yearly.
A new system for assessing delirium in older adults—the culmination of research from Harvard Medical School, Brown, and UMASS—may lead to improved clinical care, prognosis and treatment response for future patients.
Based on the current Confusion Assessment Method (CAM), the new CAM-S scoring emerged from a study funded by the National Institute on Aging and published in Annals of Internal Medicine. The CAM-S measurements of delirium pointed to a strong connection with clinical outcomes including:
- Length of hospital stay
- Nursing home placement
- Functional/cognitive decline
- Hospital and post-hospital costs
“Our findings demonstrate that the CAM-S provides a new standardized severity measure with high inter-rater reliability, and a strong association with clinical outcomes related to delirium,” says Sharon K. Inouye, M.D., M.P.H., Director of the Aging Brain Center at the Institute for Aging Research (IFAR) at Hebrew SeniorLife and professor of Medicine at Harvard Medical School (HMS).
The new CAM-S system was developed and validated in two groups of patients, all aged 70 or older. The first group of 300 patients were scheduled for major surgery as part of the Successful Aging after Elective Surgery (SAGES) study. The second group of 919 adults were admitted to the hospital as part of the Project Recovery study.
Researchers based the new scoring method on the original 4-item short form and 10-item long form versions of the CAM. They then examined the impact of the CAM-S scores on hospital and post-hospital clinical outcomes.
They found that length of hospital stay for patients increased with the degree of delirium severity—from seven days for no delirium symptoms to 13 days for severe delirium based on CAM-S short-form scores. The CAM-S long form scores showed similar increases in length of stay from six days to 12 days between no and severe symptom groups.
The researchers also found that the mean hospital costs increased along with delirium severity. Measured by the CAM-S short form, costs rose from $5,100 for patients without delirium symptoms to $13,200 for those with severe symptoms. The CAM-S long form scores showed mean costs rising from $4,200 to $11,400 across delirium symptom groups ranging from no delirium to severe.
“We believe that this measure holds great promise to improve understanding of the effects of delirium on clinical care, prognosis, pathophysiology, and response to treatment. Ultimately, we hope that this measure will help to prevent the effects of this devastating condition and improve quality of life for older adults,” says Sharon K. Inouye.