A new Yale study finds an increased risk of hospital readmission for older Americans within 180 days of undergoing major surgery — a risk that is particularly acute for individuals who are frail or have dementia.

The findings were published Feb. 28 in the journal JAMA Network Open.

Previous research by the same Yale team demonstrated that major surgery is a common event for older Americans and also demonstrated a heightened mortality risk within one year of major surgery for people who are age 65 and older. The new study is the first to describe both the short-term risk (within 30 days) and longer-term risk (within 180 days) of hospital readmission for older Americans who have recently had major surgery.

The study looked at hospital readmission among a nationally representative sample of 1,477 older Americans, not living in nursing homes, who had at least one major surgery between 2011 and 2018. More than one in four (27.6%) had a readmission to the hospital within 180 days after major surgery; nearly one in eight (11.6%) were readmitted within just 30 days.

“Prior to now, data on longer-term readmissions after major surgery in older persons have been lacking. This is problematic, as older persons undergoing major surgery represent a large and growing population,” said Dr. Robert D. Becher, associate professor of surgery at Yale School of Medicine and co-senior author of the study. “These readmission rates are high. And this study adds to our understanding of what it means to recover from major surgery as an older person.”

The numbers are even higher for those with geriatric-specific conditions such as frailty and dementia. Frail patients were readmitted within 180 days at a rate of 36.9%; patients with probable dementia were readmitted at a rate of 39%; and patients 90 years old and older were readmitted at a rate of 36.8%.

“These findings reenforce the importance of enhanced preoperative recognition of frailty and dementia in older persons and may inform patient and family expectations — and surgical decision making — about postoperative trajectories in the setting of these geriatric conditions,” said Dr. Thomas M. Gill, the Humana Foundation Professor of Geriatric Medicine at Yale and co-senior author of the study.

The issue of hospital readmission looms large in the U.S. health care system for a variety of reasons.

In 2018 alone, readmission costs totaled more than $50 billion, the researchers said. This was driven, in part, by the nearly 3.8 million 30-day hospital readmissions that year. The vast majority of those patients are Medicare beneficiaries aged 65 and older.

“From a patient perspective, the most important outcome among older persons with multiple conditions is maintaining independence and function. And we know that being readmitted to the hospital after major surgery can negatively impact that independence and function,” Becher said. “So these new data put into perspective just how common hospital readmissions, and their negative downstream consequences, are to older persons.”

The researchers said the next steps in their examination of the issue will be to further understand why vulnerable older persons have such high readmission rates and suggest meaningful ways to minimize the risk of readmission.

The study was a collaboration between Yale School of Medicine’s departments of Internal Medicine and Surgery and Yale School of Public Health’s Department of Biostatistics. The lead author of the study was Yi Wang, a postdoctoral associate at Yale School of Medicine. Co-authors were Linda Leo-Summers, Brent Vander Wyk, and Kendra Davis-Plourde.

The study was conducted at the Yale Claude D. Pepper Older Americans Independence Center and was supported in part by National Institutes of Health grants from the National Institute on Minority Health and Health Disparities and the National Institute on Aging.