5-day preoperative immunonutrition in patients undergoing major surgery for gastrointestinal cancer: a cost-effectiveness analysis under the Brazilian healthcare system perspective

Objectives: this study aims to evaluate the cost-effectiveness of 5-day preoperative enteral or oral immunonutrition in patients undergoing major surgery for gastrointestinal cancer, under the Brazilian Unified Health System (Sistema Único de Saúde - SUS) perspective. A budget impact analysis was also performed. Methods: a decision tree model was built to compare enteral or oral immunonutrition with the standard diet, considering a time horizon of 5 + 30 days. To determine the efficacy outcomes, studies using 5-day preoperative immunonutrition were retrieved from a previously published meta-analysis. New combined estimates for the occurrence of infectious complications, non-infectious complications, length of stay, and 30-day mortality were calculated using studies with a 5-day period intervention. Treatment strategies were compared using the incremental cost-effectiveness ratio (ICER). Costs were reported in Brazilian reals (BRL) and euros (EUR). Results: results combined through the meta-analysis showed that the occurrence of infectious complications was 17.2 % (65/378) and 28.8 % (99/344) for the immunonutrition and the control group, respectively (OR = 0.46; 95 % CI = 0.28-0.78; p = 0.003). Considering total costs by procedure, estimates of 930.56 BRL/151.31 EUR (267.75 BRL/43.54 EUR due to immunonutrition and 662.81 BRL/107.77 EUR due to infectious complications management) and 1,109.29 BRL/180.37 EUR (0.0 BRL/EUR due to standard diet and 1,109.29 BRL/180.37 EUR due to infectious complications management) were observed for immunonutrition and standard diet groups, respectively. Cost-effectiveness analysis showed that immunonutrition reduced the occurrence of infectious complications (-12 %) with lower costs (-178.73 BRL/-29.06 EUR). Total savings over 5 years was approximately 5 million BRL/817,352 EUR. Conclusion: 5-day preoperative enteral or oral immunonutrition not only has a positive clinical impact for patients undergoing major surgery for gastrointestinal cancer but can also generate substantial reductions in costs for SUS.