Objectives: To determine the cost-effectiveness of local insufflation (via a humidifier) of warm humidified CO2 (WH-CO2) compared with standard care in patients undergoing open or laparoscopic colorectal surgery.
Methods: A decision-analytic model was developed to estimate the costs and quality-adjusted life years (QALYs) associated with open and laparoscopic colorectal surgery from a US payer perspective. WH-CO2 was compared with no insufflation in open surgery patients and with unheated CO2 (U-CO2) in laparoscopic surgery patients. Efficacy data for open surgery patients were derived from a published randomised controlled trial reporting on the proportion of patients with hypothermia and a United States (US) hospital database analysis of post-surgery hypothermia. Data for laparoscopic surgery patients were from a United Kingdom before and after study of laparoscopic surgery patients. Other parameter inputs were obtained from published literature. Clinical event cost estimates referred to the total cost of admission to hospital for a given event. Sensitivity and scenario analyses were conducted to assess the robustness of results.
Results: Based on 200 patients using the device each year, WH-CO2 dominates standard care, as it is both cost saving ($2,355 per patient) and generates greater QALYs (0.004 per patient), over a one-year time horizon where 30% of the patients modelled underwent open surgery and 70% laparoscopic surgery. WH-CO2 dominated no insufflation in open surgery patients in 99.9% of model iterations and dominated U-CO2 in laparoscopic surgery in 99.4% of model iterations. WH-CO2 remained cost-effective at a willingness-to-pay threshold of $50,000 per QALY throughout all sensitivity analyses considered, except in the most extreme cases where the rate of clinical complications in laparoscopic patients was lower with U-CO2 than with WH-CO2.
Conclusions: The analyses suggest that, based upon currently available clinical evidence, WH-CO2 is a cost-effective use of resources for patients undergoing open or laparoscopic colorectal surgery within the US.