Introduction to propensity scores: A case study on the comparative effectiveness of laparoscopic vs open appendectomy.
ABSTRACT To demonstrate the use of propensity scores to evaluate the comparative effectiveness of laparoscopic and open appendectomy.
Retrospective cohort study.
Academic and private hospitals.
All patients undergoing open or laparoscopic appendectomy (n = 21 475) in the Public Use File of the American College of Surgeons National Surgical Quality Improvement Program were included in the study. We first evaluated the surgical approach (laparoscopic vs open) using multivariate logistic regression. We next generated propensity scores and compared outcomes for open and laparoscopic appendectomy in a 1:1 matched cohort. Covariates in the model for propensity scores included comorbidities, age, sex, race, and evidence of perforation.
Patient morbidity and mortality, rate of return to operating room, and hospital length of stay.
Twenty-eight percent of patients underwent open appendectomy, and 72% had a laparoscopic approach; 33% (open) vs 14% (laparoscopic) had evidence of a ruptured appendix. In the propensity-matched cohort, there was no difference in mortality (0.3% vs 0.2%), reoperation (1.8% vs 1.5%), or incidence of major complications (5.9% vs 5.4%) between groups. Patients undergoing laparoscopic appendectomy experienced fewer wound infections (odds ratio [OR], 0.4; 95% confidence interval [CI], 0.3-0.5) and fewer episodes of sepsis (0.8; 0.6-1.0) but had a greater risk of intra-abdominal abscess (1.7; 1.3-2.2). An analysis using multivariate adjustment resulted in similar findings.
After accounting for patient severity, open and laparoscopic appendectomy had similar clinical outcomes. In this case study, propensity score methods and multivariate adjustment yielded nearly identical results.
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ABSTRACT: Abstract Objectives: The aim of the study was to compare the long-term oncologic results of laparoscopic liver resection (LLR) versus open liver resection (OLR) for colorectal liver metastasis (CRLM) using a propensity score analysis. Subjects and Methods: This propensity score matching (PSM) study was based on a prospective database of a single tertiary-care center. Patients with primarily resectable CRLM were selected for a 1:1 PSM between LLR and OLR. Covariates for PSM estimation were age, gender, body mass index, American Society of Anesthesiologists score, primary tumor location, CRLM presentation, location, size, and number. Moreover, the year of surgery was included in the PSM model. Operative, postoperative, and survival rates were compared between groups. Results: From 2000 to 2013, in total, 339 liver resections for CRLM met the selection criteria. Among these, 52 LLR patients were matched with 52 OLR patients. The two surgical approaches showed similar postoperative morbidity and mortality rates. LLR was associated with significantly less blood loss, less frequent need for and shorter duration of pedicle clamping, faster recovery, and shorter hospital stay. Moreover, the overall 3- and 5-year survival rates were, respectively, 83% and 76% for LLR and 87% and 62% for OLR (P=.51). The 3- and 5-year disease-free survival rates were, respectively, 28% and 21% for LLR and 31% and 21% for OLR (P=.71). Conclusions: The LLR achieves similar oncological results to those of the standard open surgery for CRLM, with the additional benefit of significantly faster recovery.Journal of Laparoendoscopic & Advanced Surgical Techniques 11/2014; 25(1). DOI:10.1089/lap.2014.0477 · 1.19 Impact Factor
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ABSTRACT: To perform a population-based analysis to compare the complications and cost of laparoscopic and robotically assisted adnexal surgery. A nationwide database was used to analyze the use and outcomes of robotically assisted adnexal surgery from 2009 to 2012. Multivariable mixed effects regression models were developed to examine predictors of use of robotic surgery. After propensity score matching, complications and cost were compared between robotically assisted and laparoscopic surgery. Eighty-seven thousand five hundred fourteen women were identified. From 2009 to 2012, performance of robotic-assisted oophorectomy increased from 3.5% (95% confidence interval [CI] 3.2-3.8%) to 15.0% (95% CI 14.4-15.6%), whereas robotically assisted cystectomy rose from 2.4% (95% CI 2.0-2.7%) to 12.9% (95% CI 12.2-13.5%). The overall complication rate was 7.1% (95% CI 4.0-10.2%) for robotically assisted compared with 6.0% (95% CI 2.9-9.1%) for laparoscopic oophorectomy (odds ratio [OR] 1.20, 95% CI 1.00-1.45; P=.052). Robotic-assisted oophorectomy was associated with a higher rate of intraoperative complications (3.4% compared with 2.1%, OR 1.60, 95% CI 1.21-2.13). The overall complication rate was 3.7% (95% CI -0.8 to 8.2%) after robotically assisted compared with 2.7% (95% CI -1.8 to 7.2%) for laparoscopic cystectomy (OR 1.38, 95% CI 0.95-1.99). The intraoperative complication rate was higher for robotically assisted cystectomy (2.0% compared with 0.9%, OR 2.40, 95% CI 1.31-4.38). Compared with laparoscopy, robotically assisted oophorectomy was associated with $2,504 (95% CI $2,356-2,652) increased total costs and robotically assisted cystectomy $3,310 (95% CI $3,082-3,581) higher costs. Use of robotically assisted adnexal surgery increased rapidly. Compared with laparoscopic surgery, robotically assisted adnexal surgery is associated with substantially greater costs and a small, but statistically significant, increase in intraoperative complications. : II.Obstetrics and Gynecology 11/2014; 124(5):886-96. DOI:10.1097/AOG.0000000000000483 · 4.37 Impact Factor