SAN DIEGO – Frail elderly patients face a significantly increased risk of mortality in the year after undergoing major elective noncardiac surgery, a large study from Canada showed.
“The current literature on perioperative frailty clearly shows that being frail before surgery substantially increases your risk of adverse postoperative outcomes,” Dr. Daniel I. McIsaac said in an interview prior to the annual meeting of the American Society of Anesthesiologists, where the study was presented. “In fact, frailty may underlie a lot of the associations between advanced age and adverse postoperative outcomes. Frailty increases in prevalence with increasing age, and as we all know, the population is aging. Therefore, we expect to see an increasing number of frail patients coming for surgery.”
In an effort to determine the risk of 1-year mortality in frail elderly patients having major elective surgery, the researchers used population-based health administrative data in Ontario, to identify 202,811 patients over the age of 65 who had intermediate- to high-risk elective noncardiac surgery between 2002 and 2012. They used the Johns Hopkins Adjusted Clinical Groups (ACG) frailty indicator and captured all deaths that occurred within 1 year of surgery. Proportional hazards regression models adjusted for age, gender, and socioeconomic status were used to evaluate the impact of frailty on 1-year postoperative mortality.
Of the 202,811 patients, 6,289 (3.1%) were frail, reported Dr. McIsaac of the department of anesthesiology at the University of Ottawa. The 1-year postoperative mortality was 13.6% among frail patients, compared with 4.8% of nonfrail patients, for an adjusted hazard ratio of 2.23. Mortality was higher among frail patients for all types of surgery, compared with their nonfrail counterparts, with the exception of pancreaticoduodenectomy. Frailty had the strongest impact on the risk of mortality after total joint arthroplasty (adjusted hazard ratio of 3.79 for hip replacement and adjusted HR of 2.68 for knee replacement).
The risk of postoperative mortality for frail patients was much higher than for nonfrail patients in the early time period after surgery, especially during the first postoperative week. “Depending on how you control for other variables, a frail patient was 13-35 times more likely to die in the week after surgery than a nonfrail patient of the same age having the same surgery,” said Dr. McIsaac, who is also a staff anesthesiologist at the Ottawa Hospital. “This makes a lot of sense; frail patients are vulnerable to stressors, and surgery puts an enormous physiological stress on even healthy patients. Future work clearly needs to focus [on] addressing this high-risk time in the immediate postoperative period.”
He acknowledged certain limitations of the study, including its reliance on health administrative data and the fact that frailty “is a challenging exposure to study because there are a plethora of instruments that can be used to call someone frail. We used a validated set of frailty-defining diagnoses that have been shown to identify people with multidimensional frailty. That said, you can’t necessarily generalize our findings to patients identified as frail using other instruments.”
The findings, Dr. McIsaac concluded, suggest that clinicians should focus on identifying frail patients prior to surgery, “support them to ensure that they are more likely to derive benefit from surgery than harm, and focus on optimizing their care after surgery to address this early mortality risk.”
The study was funded by departments of anesthesiology at the University of Ottawa and at the Ottawa Hospital. Dr. McIsaac reported having no financial disclosures.