Worse outcomes in patients undergoing urgent surgery for left-sided diverticulitis admitted on weekends vs weekdays: a population-based study of 31 832 patients.

Hypothesis: Among patients undergoing urgent surgery for left-sided diverticulitis, those admitted on weekends vs weekdays have higher rates of Hartmann procedure and adverse outcomes. Design: Analysis of data from the Nationwide Inpatient Sample between January 2002 and December 2008. Unadjusted and risk-adjusted generalized linear regression models were used. Setting: Academic research. Patients: Data on patients undergoing urgent surgery for acute diverticulitis. Main Outcome Measures: Rates of Hartmann procedure vs primary anastomosis, complications, length of hospital stay, and total hospital charges. Results: In total, 31 832 patients were included; 7066 (22.2%) were admitted on weekends, and 24 766 (77.8%) were admitted on weekdays. The mean (SD) age of patients was 60.8 (15.3) years, and 16 830 (52.9%) were female. A Hartmann procedure was performed in 4580 patients (64.8%) admitted on weekends compared with 13 351 patients (53.9%) admitted on weekdays (risk-adjusted odds ratio [OR], 1.57; P < .001). In risk-adjusted analyses, patients admitted on weekends had significantly higher risk for any postoperative complication (OR, 1.10; P=.005) and nonroutine hospital discharge (OR, 1.33; P < .001) compared with patients admitted on weekdays, as well as a median length of hospital stay that was 0.5 days longer and median total hospital charges that were $3734 higher (P < .001 for both). Conclusions: Patients undergoing urgent surgery for left-sided diverticulitis who are admitted on a weekend have a higher risk for undergoing a Hartmann procedure and worse short-term outcomes compared with patients who are admitted on a weekday. Further research is warranted to investigate possible underlying mechanisms and to develop strategies for reducing this substantial weekend effect.