Objective: To evaluate the comparative safety of laparoscopic and open colectomy across surgeons varying in experience with laparoscopy.
Data sources: National Medicare data (2008-2010) for beneficiaries undergoing laparoscopic or open colectomy.
Study design: Using instrumental variable methods to address selection bias, we evaluated outcomes of laparoscopic and open colectomy. Our instrument was the regional use of laparoscopy in the year prior to a patient's operation. We then evaluated outcomes stratified by surgeons' annual volume of laparoscopic colectomy.
Principal findings: Laparoscopic colectomy was associated with lower mortality (OR: 0.75, 95 percent CI: 0.70-0.78) and fewer complications than open surgery (OR: 0.82, 95 percent CI: 0.79-0.85). Increasing surgeon volume was associated with better outcomes for both procedures, but the relationship was stronger for laparoscopy. The comparative safety depended on surgeon volume. High-volume surgeons had 40 percent lower mortality (OR: 0.60, 95 percent CI: 0.55-0.65) and 30 percent fewer complications (OR: 0.70, 95 percent CI: 0.67-0.74) with laparoscopy. Conversely, low-volume surgeons had 7 percent higher mortality (OR: 1.07, 95 percent CI: 1.02-1.13) and 18 percent more complications (OR: 1.18, 95 percent CI: 1.12-1.24) with laparoscopy.
Conclusions: This population-based study demonstrates that the comparative safety of laparoscopic and open colectomy is influenced by surgeon volume. Laparoscopic colectomy is only safer for patients whose surgeons have sufficient experience.
Keywords: Comparative safety; colectomy; instrumental variables.
© Health Research and Educational Trust.