Obesity, regardless of comorbidity, influences outcomes after colorectal surgery-time to rethink the pay-for-performance metrics?

An elevated body mass index (BMI) is associated with increased morbidity and mortality after colorectal surgery. While coexistent comorbid conditions are captured in some determinations of case-severity, BMI itself is not factored into pay for performance (P4P) initiatives. From the National Surgical Quality Improvement Program database 2006-2011, obese (BMI ≥30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) patients with and without comorbidity undergoing colorectal resection were identified. Pre- and intraoperative factors as well as postoperative outcomes were compared. Of 130,415 patients, 31.3 % were obese. 80.4 % of obese and 72.9 % of nonobese patients had comorbid conditions. Among obese patients, overall rates of surgical site infection (SSI), wound dehiscence, and various medical complications were significantly higher for those with comorbidity compared to those without (p < 0.001 for all). Obese patients with comorbidity overall had greater risk of renal failure and urinary tract infection than nonobese patients. Regardless of comorbidity, obese patients more commonly had pulmonary embolism, failure to wean from the ventilator, overall SSI, and wound dehiscence. Comorbid factors associated with obesity influence outcomes; however, obesity itself in their absence is associated with worse outcomes. This supports inclusion of obesity as an independent determinant of case-severity, quality, and reimbursement after colorectal surgery.