Obese patients appear to have a significantly increased risk of developing a surgical site infection after segmental or total colectomy for colon cancer, diverticulitis, or inflammatory bowel disease, and the presence of infection increases the cost associated with the procedure, according to a report posted online and scheduled for publication in the September issue of Archives of Surgery.
“We chose to study colectomy as a standardized procedure because the risk of [surgical site infection] following this procedure is known to be greater than that following other abdominal procedures,” wrote Elizabeth C. Wick, MD, and colleagues, of the Johns Hopkins University School of Medicine and Johns Hopkins Bloomberg School of Public Health, Baltimore. They evaluated surgical site infection rates among obese and nonobese colectomy patients using claims data from 7,020 members of eight different Blue Cross Blue Shield insurance plans.
Among these patients, 1,243 were identified as obese (body mass index ≥ 30) and 5,777 were classified as nonobese. The overall rate of surgical site infection was 10.3%, with obese patients experiencing a higher rate, 14.5%, compared to 9.5% for nonobese patients. After adjusting for laparoscopy, diagnosis, gender, and age, obesity was the strongest predictor of surgical site infection, with obese patients experiencing a 60% increased risk compared to nonobese patients.
The mean cost of colectomy was $16,399, but approximately $295 more for obese patients. On average, developing a postoperative surgical site infection was associated with increased cost of the colectomy ($31,933 for patients with infection vs $14,608 for patients without infection), increased length of hospital stay (average of 9.5 days vs 8.1 days), and a significantly higher rate of hospital readmission (27.8% vs 6.8%).
The authors concluded that patients undergoing colorectal surgery who develop surgical site infections, many of whom are obese, tax the health-care system. “Pay-for-performance policies in surgery should account for the increased risk of infection and cost of caring for this population. Failure to consider these differences could lead to perverse incentives that may penalize surgeons who care for obese patients and may even affect obese patients’ access to colorectal surgery,” they said. ■
Wick EC, et al: Arch Surg. May 16, 2011 (early release online).