Study Shows: No Low-Risk Surgeries in High-Risk, Frail Patients

BACKGROUND:
Frailty is a global syndrome of decreased physiological reserve accurately measured by the Risk Analysis Index (RAI). Surgical stress can exhaust frail patients’ limited reserve, leading to catastrophic decompensation and death. However, there is an inadequate understanding of whether frailty’s association with poor outcomes varies with the physiologic stress of operation. Many surgical procedures are considered so minor that surgeons spend little time considering if patients can endure the stress of surgery. Yet if frailty predicts adverse outcomes after such low-risk, ambulatory operations, it is important to identify and counsel frail patients before these relatively minor procedures. Therefore, this retrospective cohort study examined the relationship among operative stress, frailty, and postoperative mortality. Using data from the VA Surgical Quality Improvement Program (VASQIP) database, investigators identified all Veterans (n=432,828) who underwent a non-cardiac surgical procedure between April 2010 and March 2014 and had information available on vital status one-year post surgery. Of this mostly male study cohort, 36,579 (9%) were considered frail and 9,113 (2%) were very frail. Study investigators then used a novel Operative Stress Score (OSS) they developed to quantify physiologic stress for surgical procedures, which allowed for a comparison of the impact of frailty across an array of procedures with different levels of operative stress.

FINDINGS:

• Frailty was associated with increased 30-, 90- and 180-day mortality across all levels of operative stress. Frail patient mortality after low and moderate stress procedures was substantially higher than mortality rates usually associated with “high-risk” surgery.
• For frail patients undergoing lowest-stress operations (i.e., cystoscopy) and moderate-stress operations (i.e., laparoscopic cholecystectomy), 30-day mortality rates were 2% and 5%, respectively, both exceeding the 1% mortality rate often used to define high-risk surgery.
• For very frail patients, 30-day mortality rates after lowest and moderate-stress procedures were higher, at 10% and 19%, respectively.
• For frail and very frail patients, mortality continued to rise at 90 and 180 days, reaching as high as 43% for very frail patients 180 days after moderate-stress operations.

IMPLICATIONS:

• Even minor operations are high-risk for frail patients, thus efforts to screen patients for frailty should not just focus on high-stress procedures, but also on the low-stress procedures that are deceptively risky among frail patients.

LIMITATIONS:

• The OSS is a physician-rated measure and does not include objective physiologic criteria.
• Because all cause mortality was examined and investigators did not have a control group who did not undergo surgery, mortality is not able to be attributed directly to surgery.

AUTHOR/FUNDING INFORMATION:
This study was partly funded by HSR&D. Drs. Youk and Hall are part of HSR&D’s Center for Health Equity Research & Promotion (CHERP). Dr. Massarweh is part of HSR&D’s Center for Innovations in Quality, Effectiveness and Safety (IQuESt).

Shinall M, Arya S, Youk A, Varley P, Shah R, Massarweh N, Shireman P, Johanning J, and Hall D for the OSS (Operative Stress Score) Study Group. Association of Preoperative Patient Frailty and Operative Stress with Postoperative Mortality. JAMA Surgery. Nov 13, 2019; Epub ahead of print.