Breast surgery outcomes as quality measures according to the NSQIP database

The National Surgical Quality Improvement Program (NSQIP) is a risk-adjusted database designed to benchmark quality initiatives. NSQIP captures uniform morbidity variables for all operations and calculates expected morbidity probabilities. Given the frequent need for reoperation following breast-conserving surgery (BCS) and mastectomy, we hypothesized that NSQIP may inaccurately reflect surgical morbidity after breast cancer operations.

Using the 2008 NSQIP database, we identified 24,447 breast surgery patients. We calculated the observed versus expected (O/E) morbidity ratios, compared them to other general surgery procedures, and analyzed the O/E morbidity ratios among benign and malignant breast diagnoses.

The NSQIP database shows that breast surgery has an O/E morbidity ratio of 3.11, which is higher than other general surgery procedures. Additionally, breast operations for malignancy have higher O/E morbidity ratios (3.22) than those performed for benign disease (2.59). Analysis of malignant patients by CPT code revealed that BCS patients had an O/E morbidity ratio of 7.75 and attributed 89 % of morbidity to reoperation, whereas mastectomy patients had an O/E morbidity ratio of only 1.7. Elimination of the reoperation variable from morbidity calculations in breast surgery reduces the O/E morbidity ratio to less than expected in all breast procedures.

Breast surgery has a higher O/E morbidity ratio than other general surgery procedures. Reoperations are expected in BCS for positive margins and in mastectomy for completion ALND. Breast surgeons should advocate for benchmarking by surgical site-specific metrics, because current NSQIP criteria may negatively affect the quality assessment of high-volume breast centers.