Simultaneous versus staged resection for synchronous colorectal liver metastases: A population-based cost analysis in Ontario, Canada - Health economic evaluation.

ABSTRACT

BACKGROUND: Simultaneous compared to staged resection of synchronous colorectal cancer liver metastases is considered safe. We aimed to determine their cost implications. STUDY DESIGN: Population-based cohort was generated by linking administrative healthcare datasets in Ontario, Canada (2006-2014). Resection of colorectal cancer and liver metastases within six months was considered synchronous. Cost analysis was performed from the perspective of a third-party payer. Median costs with range were estimated using the log-normal distribution of cost using t-test with a one-year time horizon. RESULTS: Among patients undergoing staged resection (n = 678), the estimated median cost was $54,321 CAD (IQR 45,472 to 68,475) and $41,286 CAD (IQR 31,633 to 58,958) for those undergoing simultaneous resection (n = 390), median difference $13,035 CAD (p < 0.001). Primary cost driver were all costs related to hospitalization for liver and colon resection, which was higher for the staged approach, median difference $16,346 CAD (p < 0.001). This was mainly due to a longer median length of hospital stay in the staged vs. simultaneous group (11 vs. 8 days, p < 0.001 respectively), which was not attributable to differences in major postoperative complication rates (23% vs. 28%, p = 0.067 respectively). Other costs, including cost of chemotherapy within six months of surgery ($11,681 CAD vs. $8644 CAD, p = 0.074 respectively) and 90-day re-hospitalization cost ($2155 CAD vs. $2931 CAD, p = 0.454 respectively) were similar between groups. CONCLUSION: Cost of staged resection of synchronous colorectal cancer liver metastases is significantly higher compared to the simultaneous approach, mostly driven by a longer length of hospital stay despite similar postoperative complication rates.