N. Tata1, J. Dunderdale2, I. Helenowski3, B. Jovanovic3, R. Marcus4, S. Kulkarni2 1Feinberg School Of Medicine – Northwestern University,Chicago, IL, USA 2Feinberg School Of Medicine – Northwestern University,Department Of Surgery,Chicago, IL, USA 3Feinberg School Of Medicine – Northwestern University,Department Of Preventative Medicine,Chicago, IL, USA 4Feinberg School Of Medicine – Northwestern University,Department Of Anesthesia,Chicago, IL, USA
Introduction: The current obesity epidemic is associated with increased health care costs and comorbidities such as diabetes and heart disease. However, the effect of obesity on OR utilization has not been completely evaluated. The goal of our study was to examine how operative time (OPT) and total time in the operating room (TTOR) for common breast procedures are affected by patient BMI. We hypothesized that operating room utilization would vary significantly with BMI, with the difference being greater for more extensive breast procedures compared to minimally invasive procedures.
Methods: For this study, the American College of Surgeons National Surgical Quality Improvement Project (NSQIP) databases for 2010-2012 were searched. Patients undergoing the selected breast operations were filtered out by CPT code. They were divided into groups based on their BMI and their weight. Using the two-sample t-test, OPT and TTOR for the procedures were compared among the lowest and highest BMI categories, as well as the lowest and highest weight categories. To further characterize the effect of BMI on operative time, a linear regression t-test was used to demonstrate increase in OPT as a function of unit increase in BMI.
Results: When the lowest and highest BMI groups were compared for all procedures, significant differences in OPT and TTOR were seen (p<0.0001). Ultimately, our analysis included 47,557 patients for OPT data and 32, 455 for TTOR data. Overall, there was a fourteen minute difference in OPT and an eighteen minute difference in TTOR. Similarly, when the lowest and highest weight categories were compared for all procedures, a significant difference in OPT of thirteen minutes was seen, while the difference in TTOR was seventeen minutes. In both BMI and weight analyses, though significant differences were noted for lumpectomy alone and lumpectomy plus SLNB, the effect of patient BMI on ALND and mastectomy is even more pronounced.
For every ten unit increase in BMI, there was a 9.6 minute increase in operative time for lumpectomy ALND and 14.3 minutes increase for mastectomy ALND procedures. For simpler procedures like lumpectomy and lumpectomy SNLB, the increase in operative time with ten unit BMI increase was 2.4 and 5.2 minutes respectively.
Conclusion: Patient BMI and weight significantly affect OPT and TTOR for common breast procedures. However, the difference is greater for ALND and mastectomy. Therefore, when scheduling more extensive breast procedures, patient BMI should be taken into account to improve operating room scheduling and adjust physician compensation.