Depression and dementia in older adults increase risk of preventable hospitalizations

New research in the Journal of General Internal Medicine finds that mental health conditions in older adults such as depression, cognitive impairment and dementia are risk factors for hospitalization for ambulatory care-sensitive conditions (ACSCs) – conditions that can often be managed effectively on an outpatient basis. The research also found that older adults with depression or cognitive impairments have a higher risk of readmission within 30 days after a hospital stay for pneumonia, heart attack or congestive heart failure.

Major drivers of U.S. health care costs, especially those paid by Medicare, are hospitalizations and readmissions. A 2008 report from the Agency on Healthcare Research and Quality (AHRQ) found one in ten hospitalizations may be preventable.

Dimitry S. Davydow, MD, MPH, associate professor in the Department of Psychiatry and Behavioral Sciences at the University of Washington and lead author of the study, explained that in addition to increases in health care costs, such hospitalizations can take a profound toll on the health status of older adults. Many older adults who are hospitalized may develop new and persistent cognitive problems, and some may have adverse effects to their mental health.

"In our sample of Medicare beneficiaries, we found that 14 percent of hospitalizations for ambulatory care-sensitive conditions, as well as 15 percent of rehospitalizations within 30 days of a hospitalization for pneumonia, heart attack or congestive heart failure, could be due to depression, cognitive impairment or some combination of the two," Davydow said.

The researchers reviewed responses from 7,031 adults over 50 who participated in the 1998-2008 Health and Retirement Study (HRS) of the University of Michigan Institute of Social Research and who agreed to allow researchers to analyze their Medicare claims records. Participants were interviewed every two years for the HRS study.

"I hope this study will lead to health systems taking into account factors like psychiatric disorders, dementia and more mild cognitive impairment when considering how to go about working to reduce potentially preventable hospitalizations and rehospitalizations," Davydow said.

Robert P. Roca, MD, MPH, MBA, chair of the American Psychiatric Association's Council on Geriatric Psychiatry, said the study adds to research literature by documenting the interactions between general health conditions and mental health.

"The bottom line is that we cannot provide the most effective general medical care to older adults or control health care costs associated with hospitalization without taking mental health conditions into account," Roca said. "We must know when our patients have symptoms of depression and evidence of cognitive impairment and incorporate this knowledge into our discharge planning and ambulatory care processes. We need psychiatrists and other mental health experts working in general medical settings to directly assist in this work."

"Depression as well as cognitive impairments, including dementia, are prevalent among older Americans," Davydow said. "Of all the interventions that have currently been designed to try to tackle potentially preventable hospitalizations, very few have considered the role that poor mental health and/or cognitive impairment may play."

Roca, who is also vice president and medical director of the Sheppard Pratt Healthy System in Towson, MD, noted that hospital research is showing that many patients who are readmitted for medical conditions have concurrent mental health conditions.

"It is a very reasonable hypothesis," he said, "that attending closely to the special needs of these patients, perhaps through targeted case management efforts guided by mental health experts after discharge, may turn this situation around."