Influence of obesity on complications and costs after intestinal surgery

Obesity is a risk factor for many comorbid conditions that increase the cost of health care. We sought to examine the effect of obesity on surgical complications and cost in a group of patients undergoing intestinal surgery.

Using the Veterans Affairs Surgical Quality Improvement Program (VASQIP), which includes clinical data abstracted from medical records for Veterans Affairs (VA) surgical patients, and the VA Decision Support System, which provides the costs of individual patient encounters on the basis of relative values assigned to intermediate products, we examined surgical complications and costs of care in 4,881 patients undergoing intestinal surgery in 2006. Patients were classified into 4 groups based on body mass index (BMI): malnourished (<18), normal weight (18-30), obesity class I to II (30-40), and obesity class III (>40). Patient endpoints included the occurrence of any complication and surgical costs incurred within 30 days of surgery. Endpoints were compared across the 4 BMI categories in unadjusted analyses and risk-adjusted analyses and hospital-level variation using multivariable models.

After controlling for patient risk factors and hospital-level variation, patients in obesity class I to II were 1.21 times more likely to have any complication and patients in obesity class III were 1.41 times more likely to have any complication when compared with normal-weight patients. Similarly, patients in obesity class I to II were 1.44 times more likely to develop a wound complication compared with normal-weight patients, and patients in class III were 1.84 times more likely to develop a wound complication and 1.55 times more likely to develop a respiratory complication compared with normal-weight patients. In contrast, costs were greatest for malnourished patients at $45,000 compared with normal-weight patients at $37,000. However, after controlling for patient risk factors and variation in costs attributable to the admitting hospital, there were no significant cost differences between the 4 BMI categories.

Obesity leads to increased wound and respiratory complications in intestinal surgery. Nevertheless, obesity alone is not an independent risk factor for increased costs in intestinal surgery.