WBC Associates with Readmission Following Cystectomy

Background: Radical cystectomy is associated with perioperative complication rates exceeding 50% in some series. Readmission rates are increasingly used as a surgical quality metric. White blood cell count is a crude surrogate for physiologic processes which may reflect postoperative complications leading to readmission. Objective: We assessed the association between final white blood cell count at discharge and risk of readmission following radical cystectomy. Methods: Records on 477 patients undergoing radical cystectomy from 2006-2013 were reviewed. Final white blood cell count was defined as the last documented value during index admission. Univariate analysis was performed using Fisher's exact, Wilcoxon rank sum test, and Spearman's coefficient tests where appropriate. Multivariable logistic regression models were used to test the associations between final white blood cell count and readmission. Results: 34% of patients were readmitted within 90 days of surgery. Amongst this cohort, a cutoff final white blood cell count of 9000/mm³ was identified, with a significantly higher proportion of patients with values >9000/mm³ experiencing readmission than those with values≤9000/mm³ (42% vs 28%, p = 0.004). Other perioperative variables associated with an increased readmission rate included initial hospital length of stay≤10 days, and receipt of a continent diversion. Following adjustment, final white blood cell count >9000/mm³ was associated with increased risk of readmission (OR 2.09, 95% CI 1.23-3.53, p = 0.006). Conclusions: Final white blood cell count is associated with hospital readmission following radical cystectomy. This metric may provide important guidance in discharge algorithms.