Delirium episodes during hospitalization are not isolated occurrences for patients with Alzheimer’s disease, according to research by HMS investigators at the Institute for Aging Research at Hebrew SeniorLife. In fact, these acute instances of cognitive decline that affect attention and executive function, sometimes for several days, can result in sharply increased rates of mental deterioration for up to five years post-hospitalization. This long-term outcome can be especially troubling for Alzheimer’s patients; when hospitalized, patients with this neurodegenerative disease often experience episodes of delirium. The study is the first to examine the significance of the prevalence of delirium over an extended period.
The study, published online August 20 in Archives of Internal Medicine, showed that patients who developed delirium during hospital stays experienced greater cognitive deterioration in the year following their hospitalization than those who had no episodes of delirium while hospitalized. In addition, mental deterioration in those experiencing delirium proceeded at twice the rate of those who were without delirium in the year after hospitalization. And for five years after their hospital stays, those who had suffered episodes of delirium maintained a more rapid rate of cognitive deterioration.
According to Alden Gross, lead author of the study and an HMS research fellow in medicine at Beth Israel Deaconess Medical Center, the annual cost of delirium to the U.S. health care system is between $40 and $150 billion. Although strategies to treat delirium when it occurs during hospitalization are still being studied, he adds, the study’s findings indicate that it may be important to implement proven strategies to prevent it from occurring in the first place.