Timing of discharge: a key to understanding the reason for readmission after colorectal surgery

There is a growing interest in surgery regarding the balance between appropriate hospital length of stay (LOS) and prevention of unnecessary readmissions. This study examines the relationship between postoperative LOS and unplanned readmission after colorectal resection, exploring whether patients discharged earlier have different readmission risk profiles.

Patients undergoing colorectal resection were selected by Common Procedural Terminology (CPT) code from the 2012 ACS National Surgical Quality Improvement Program (NSQIP) database. Patients were stratified by LOS quartile. Kaplan-Meier analysis was used to examine characteristics associated with 30-day unplanned readmission. Factors with a p < 0.1 were included in the Cox proportional hazards model. Subsequently, chi-square analysis compared LOS, patient, and perioperative factors with the primary reason for readmission. Factors with a p < 0.2 were included in a multivariable logistic regression for each readmission reason.

For 33,033 patients undergoing colorectal resection, the overall 30-day unplanned readmission rate was 11 %. After adjusting for patient and perioperative factors, a postoperative LOS ≥8 days was associated with a 55 % increase in the relative hazard of readmission. Patients with a ≤3-day LOS were more likely to be readmitted with ileus/obstruction (odds ratio (OR): 1.8, p = 0.001) and pain (OR: 2.2, p = 0.007). LOS was not significantly associated with readmission for intraabdominal infection or medical complications.

Patients with longer LOS and complicated hospital courses continue to be high risk post-discharge, while straightforward early discharges have a different readmission risk profile. More targeted readmission prevention strategies are critical to focusing resource utilization for colorectal surgery patients.