F. J. Baky1, B. C. Housley1, N. Kelly1, M. J. Lin2, E. Pletcher2, S. P. Stawicki2, D. C. Evans1 1Ohio State University,Surgery,Columbus, OH, USA 2St. Luke’s University Health Network,Surgery,Bethlehem, PA, USA
Introduction:
Vascular surgery patients are at increased risk of perioperative complications, readmissions, and mortality. Comorbidity-polypharmacy score (CPS) – a simple sum of pre-existing medical conditions and medications – has been shown to predict morbidity, mortality, and readmissions in older trauma patients. Our study examines the utility of CPS as a predictor of morbidity, mortality and readmissions in patients undergoing lower extremity bypass. We hypothesize that CPS is predictive in all three domains outlined above.
Methods:
An IRB-approved, two-institution retrospective study of lower extremity bypass patients was conducted using records between Jan 2008 and Dec 2014. Records for above- and below-knee bypass procedures, including vein and prosthetic grafts, were included. Collected data included demographics, surgery characteristics, complications, hospital lengths of stay, and readmissions (30-, 180-, and 360-day). Comorbidity-polypharmacy score was calculated using patient records and stratified as low (0-14) or high (15 or greater). Univariate and multivariate analyses of factors associated with key outcome parameters (mortality, morbidity, and readmission) were performed using SPSS 18 Software (IBM Corp., Armonk, NY). Data are reported as frequencies/mean±standard deviation for univariate analyses and odds ratios with 95% confidence intervals for multivariate outcomes.
Results:
248 patients were included in the analysis (43.5% male, mean age 64.27±11.79, mean BMI 27.65±6.43, 50% above-knee, 94% non-emergent, 65% prosthetic, 79.5% primary). There were 121 patients in ‘low CPS’ group and 127 patients in the ‘high CPS’ group. On univariate analyses, CPS was significantly associated with age, BMI, hospital length of stay, 180- and 360-day cumulative readmissions, infection, cardiovascular complications and stroke (Table 1). On multivariate analyses, predictors of stroke included age (OR 1.06, 95%CI 1.014-1.111), CPS (OR 1.080, 1.014-1.0149), and procedure duration (OR 1.010, 1.006-1.014). Independent predictors of cardiovascular complications included CPS (OR 1.065, 1.004-1.128) and longer procedure duration (OR 1.009, 1.002-1.015). Predictors of infection included CPS (OR 1.061, 1.007-1.118) and in-hospital complication (OR 4.427, 1.714-11.435). CPS did not independently predict readmissions or mortality in the patient sample.
Conclusion:
Comorbidity-polypharmacy score is an independent predictor of complications in postoperative lower extremity bypass patients. However, it does not independently predict readmissions or mortality. Given these preliminary results in non-trauma CPS application, further research is warranted in this clinically important area.
