A Stefanou, MD, C Reickert, MD, A Falvo, DO, V Velanovich, MD, I Rubinfeld, MD. Henry Ford Hospital
Introduction: The goal of our study is to evaluate if patients undergoing laparoscopic colectomy have a statistically shorter length of stay when compared to patients undergoing open colectomy. We evaluated National Surgical Quality Improvement Program (NSQIP) data to investigate if this is a valid assumption, and how mode of operation affects length of stay. Because most current literature tends not to adjust for biases in patient selection that could provide alternative explanation for length of stay, we aimed to control for this to provide a clear model of laparoscopic operation and length of stay.
Methods: Using four years of NSQIP public use files (PUF 2005-8), we used CPT coding to select all colectomies and further label the laparoscopic procedures. Patients were labeled as to being outside the 75th percentile of surgical length of stay (SLOS). Logistic regression analysis was used to predict this outlier status. We also utilized linear regression to directly predict SLOS. Acuity adjustment was done using the most popular variables from multiple NSQIP annual reports. This work was done under the approval of our institutional review board and the data use agreement of the American College of Surgeons. Data was analyzed in SPSS (SPSS, Chicago, IL).
Results: A total of 45,645 colectomies were reviewed, of which 12,455 (27.3%) were laparoscopic. The 75th percentile for SLOS was 11 days. This implied 9,249 (27.9%) of the open colectomies were outliers, while only 1,152 (9.2%) of laparoscopic colectomies were outliers (p<.001). When optimizing a simple linear regression to predict SLOS, using common acuity adjustors (i.e. age, functional status, ASA, wound category, various occurrences, etc.), the variable marking open procedures consistently had a coefficient of 1.8, implying open procedures increased SLOS by 1.8 days (p<.001). Utilizing logistic regression to predict outlier status, open colectomies were associated with an odds ratio of 2.27 for outlier status (p<.001). Thus implying an independent effect on SLOS.
Conclusion: Our data indicates that laparoscopic colectomy independently decreases length of stay when compared to patients who undergo open operation. This is important because although this is widely assumed, it has never been analyzed with intent to acuity adjust the patient populations examined. When comparing patients in these two categories we were able to compare the groups and use statistical methods to control for selection bias of patients who might be more “surgically fit”. Additionally, health care costs are under increasing scrutiny and laparoscopic procedures generally are more expensive to the institution. Demonstrating an across the board improvement in SLOS with laparoscopy will be useful in policy discussions.
Program Number: S021