Colorectal cancer surgery for obese patients:Financial and clinical outcomes of a Dutch population-based registry

Background and Objectives The objective of this study was to explore the association among adverse events, body mass index (BMI), and hospital costs after colorectal cancer surgery in a country with an intermediate BMI distribution. Methods All colorectal cancer procedures in 29 Dutch hospitals listed in a 2010-2012 population-based database and with a BMI > 18.5 were included (n = 8687). Hospital costs were measured uniformly and based on time-driven activity-based costing. The BMI classification of the World Health Organization was used. Results Patients in obesity classes 1 (23.6% [after risk-adjustment OR 1.245, CI 1.064-1.479, P = 0.007]) and =2 (28.1% [after risk-adjustment OR 1.816, CI 1.382-2.388, P < 0.001]) were associated with more severe complications and higher hospital costs (€14,294, +9.6%, after risk-adjustment +7.9%, P < 0.001; and €15,913 +22.0%, after risk-adjustment +21.2%, P < 0.001, respectively) than normal weight patients (20.8% and €13,040, respectively). Pre-obese patients had significantly lower mortality rates (2.7%, after risk-adjustment, OR 0.756, CI 0.577-0.991, P = 0.042) than normal-weight patients (3.9%). Conclusions Obese surgical colorectal cancer patients in a country with an intermediate BMI distribution are associated with a significant increase in hospital costs because these patients suffer from more severe complications. This is the first study to provide evidence for the "obesity-paradox" for mortality in colorectal cancer surgery