IMPORTANCE Readmission is a target area of quality improvement in surgery. While variation in readmission is common, to our knowledge, no study has specifically examined the underlying etiology of this variation among a variety of surgical procedures performed in a large academic medical center. OBJECTIVE To quantify the variability in 30-day readmission attributable to patient, surgeon, and surgical subspecialty levels in patients undergoing a major surgical procedure. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of administrative claims data of patients discharged following a major surgical procedure at a tertiary care center between January 1, 2009, and, December 31, 2013. A total of 22 559 patients were included in this study and underwent a major surgical procedure performed by 56 surgeons practicing in 8 surgical subspecialties. MAIN OUTCOMES AND MEASURES In-hospital morbidity, 30-day readmission, and proportional variation in 30-day readmission at patient, surgeon, and surgical subspecialty levels. RESULTS Among the 22 559 patients in this study, patient age, race/ethnicity, and payer type differed across surgical subspecialties. Preoperative comorbidity was common and noted in 65.1% of patients. Postoperative complications were noted in 21.6% of patients varying from 2.1% following breast, melanoma or endocrine surgery to 37.0% following cardiac surgery. The overall 30-day readmission was 13.2%(n = 2975). Readmission varied considerably across the 8 different surgical subspecialties, ranging from 24.8% following transplant surgery (n = 557) to 2.1% following breast, melanoma, or endocrine surgery (n = 32). After adjusting for patient-and surgeon-level variables, factors associated with readmission included African American race/ethnicity (odds ratio, 1.23; 95% CI, 1.11-1.36; P < .001), increasing comorbidity (Charlson Comorbidity Index score of 1: odds ratio, 1.16; 95% CI, 1.02-1.32; P = .02; and a Charlson Comorbidity Index score of >= 2 : odds ratio, 1.38; 95% CI, 1.24-1.53; P < .001), postoperative complication (odds ratio, 1.19; 95% CI, 1.08-1.32; P = .001), and an extended length of stay (odds ratio, 1.78; 95% CI, 1.61-1.96; P < .001). The majority of the variation in readmission was attributable to patient-related factors (82.8%) while surgical subspecialty accounted for 14.5% of the variability, and individual surgeon-level factors accounted for 2.8%. CONCLUSIONS AND RELEVANCE Readmission occurred in more than 1 in 10 patients, with considerable variation across surgical subspecialties. Variation in readmission was overwhelmingly owing to patient-level factors while only a minority of the variation was attributable to factors at the surgical subspecialty and individual surgeon levels.
