Key Points
- This research aims to understand how patient surgical risk influences the outcomes of coronary artery bypass grafting across hospitals with varying volumes.
- Analyzed clinical data on 27,355 adults who underwent CABG at 68 hospitals in California from 1997 to 1998.
- Categorized hospitals into low, medium, and high volume based on annual CABG procedures.
- Employed hierarchical logistic regression and log-binomial regression models to evaluate mortality rates and surgery likelihood based on hospital volume and surgical risk.
- Adjusted in-hospital mortality rates differed significantly between low- and high-volume centers, increasing with expected risk (0.8% vs 0.4% at the 20th risk percentile and 3.8% vs 2.5% at the 80th risk percentile, P<.001).
- The likelihood of undergoing CABG at low-volume centers increased with expected surgical risk, showing a relative risk of 1.29 for patients at the 80th risk percentile compared to the 20th (95% CI, 1.14-1.51; P<.001).
Structured PICO
Does hospital volume affect in-hospital mortality rates for patients undergoing CABG, and are high-risk patients more likely to be treated at low-volume centers?
PPopulation27,355 adults who underwent coronary artery bypass grafting (CABG) at 68 hospitals in California between 1997 and 1998
IInterventionCABG performed at low-volume (n=44) or medium-volume (n=19) hospitals
CComparatorCABG performed at high-volume (n=5) hospitals
OOutcomeIn-hospital mortality rates across hospital volume categories by expected surgical risk, and the likelihood of CABG being performed in each hospital volume categoryhard clinical
High-risk patients undergoing CABG are paradoxically more likely to be treated at low-volume hospitals, where their risk of in-hospital mortality is significantly higher compared to high-volume centers.