Is the impact of hospital and surgeon volumes on the in-hospital mortality rate for coronary artery bypass graft...

Area of Science:

• Cardiovascular Surgery
• Health Services Research
• Surgical Outcomes

Background:

• Previous research on volume-based referral for coronary artery bypass grafting (CABG) surgery has yielded conflicting results, particularly for low-risk patient groups.
• Guidelines suggest restricting CABG referrals to high-risk patients, but evidence for low-risk populations remains debated.

Purpose of the Study:

• To investigate the relationship between provider volume (hospital and surgeon) and in-hospital mortality for both low-risk and moderate-to-high-risk patients undergoing isolated CABG surgery.
• To determine if higher surgical and hospital volumes are associated with improved outcomes across different risk strata.

Main Methods:

• Analysis of 57,150 isolated CABG procedures performed in New York between 1997 and 1999.
• Patients were stratified into low-risk and moderate-to-high-risk groups based on a predicted in-hospital death probability of 2%.
• Examined the association between annual hospital volumes (200-600 cases) and surgeon volumes (50-150 cases) with in-hospital mortality using adjusted odds ratios (ORs).

Main Results:

• Higher hospital volumes were associated with significantly lower in-hospital mortality for low-risk patients (ORs 0.45-0.77) and moderate-to-high-risk patients (ORs 0.62-0.91).
• Higher surgeon volumes also demonstrated a protective effect, with lower mortality rates observed for both risk groups.
• Patients treated at higher-volume hospitals by higher-volume surgeons had a substantially reduced risk of death (OR 0.52 for low-risk group).

Conclusions:

• Increased provider volume, encompassing both hospital and surgeon experience, is consistently associated with reduced in-hospital mortality following CABG surgery.
• These findings support the consideration of provider volume as a critical factor in referral decisions for CABG procedures, irrespective of patient risk level.
• Optimizing patient outcomes may involve directing CABG cases to centers and surgeons with established high-volume practices.