Obesity Complicates Surgery, Highlighting Need for Coding Fixes

Performing abdominal surgery procedures on overweight and obese individuals consistently results in longer operating times and an increased risk for complications.

As the obesity epidemic continues to worsen in the United States, surgeons more regularly can expect to perform procedures on this high-risk population, highlighting the need for changes to existing coding procedures to ensure proper payment for difficult and longer surgeries (J Am Coll Surg 2025 Feb 27. doi:10.1097/XCS.0000000000001367).

“Surgeons should be able to identify cases that are extraordinarily hard, and should be compensated for these complex cases,” Christopher P. Childers, MD, PhD, a surgical oncologist in the Department of Surgery at the University of Washington, in Seattle, told General Surgery News.

At this time, Current Procedural Terminology (or CPT) codes do not provide an efficient, effective way for surgeons to identify complex procedures.

Previous research conducted by Dr. Childers and his colleagues found that modifier 22, which can be appended to a billing code to identify an increased procedural service, is often ineffective, leading to minimal increase in payment to surgeons (JAMA Surg 2024;159[5]:563-569).

“At an institutional level, when you submit a claim with modifier 22 on it, the claim often is automatically declined,” Dr. Childers said. “Modifier 22 is extremely vague in its definition of what justifies increased procedural services, and there are no published criteria on what does or doesn’t quality for its use.”

This lack of consistency regarding when to use modifier 22 and whether insurers will approve or deny its use, demonstrates the need for an updated approach to coding, particularly as it relates to managing patients who will likely require longer or more difficult procedures, such as those who are obese.

“Every procedural code is based on what’s called the typical patient,” said Christopher Senkowski, MD, a professor of surgery and the director of the general surgery residency program at Florida International University/Baptist Health South Florida, in Miami, who serves as chair of the American College of Surgeons (ACS) General Surgery Coding and Reimbursement Committee.

This means that metrics for payments are calculated due to assumptions based on the characteristics of these typical patients. However, as issues such as obesity become increasingly common, what is designated as typical may be increasingly out of touch with true patient populations, particularly for procedures such as abdominal surgery.

“Obesity has become an increasing part of our daily practice as physicians in all specialties because of the obesity epidemic and rising BMI [body mass index] across America,” Dr. Senkowski said.

Dr. Childers concurred. “The overweight and obese population has been growing over time. While there are new drugs on the market that are potentially going to slow that growth, there has been a substantial increase in these patients, and they are often more prone to developing some of these disease processes.”

Thinking about patient factors that might be very objective, thus allowing clinicians to accurately identify patients in advance who may be require additional effort, led Drs. Childers and Senkowski and their colleagues to study obesity.

Using data from the 2022 Participant Use File from the ACS National Surgical Quality Improvement Program, they researched how BMI category affected operative time and complications for patients undergoing 10 common abdominal procedures.

The final study sample included 158,692 operations. In the overall patient population, 1.5% were underweight (BMI <18.5 kg/m²), 22.2% were normal weight (BMI, 18.5-25 kg/m²), and 76% were considered overweight or obese (BMI >25 kg/m²). Of the overweight and obese individuals, 34% were overweight, 22.8% had class I obesity, 11.1% had class II obesity, 6.9% had class III obesity and 1.5% had extreme obesity.

The investigators found that obese patients had longer operating times than those with normal BMI across all procedures. Additionally, in eight of 10 studied operations, overweight patients also had longer operating times than those with a normal BMI.

When all procedures were combined into a single model, operating times increased by a rate of 5.6% for overweight patients, 10.6% for class I, 14.7% for class II, 18.9% for class III and 26.8% for extreme obesity.

Obesity was associated with higher odds of both any complication and serious complications, and being overweight was associated with increased odds of any complication.

“There was a very linear, consistent increase in operative time and risk of complications across each of the categories,” Dr. Childers said. “This suggests that there is a kind of universality to the challenge of obesity for these patients.”

The findings showed that BMI may be a useful characteristic to identify in advance which subsets of patients may require additional work, thus aiding the ACS in developing recommendations for how to revise coding procedures.

“This research study is one of the first data sets that supports increased reimbursement for obese patients that have abdominal surgery,” Dr. Senkowski said.