Risk Factors for the Failure of Non-operative Management Among Patients Admitted for Colonic Diverticulitis

Background: Diverticulitis is one of the most diagnosed gastrointestinal diseases in the country, and its incidence has risen over time, especially among younger populations, with increasing attempts at non-operative management. We elected to look at acute diverticular disease from the lens of a failure analysis, where we could estimate the hazard of requiring operative intervention based upon several clinical factors. Materials and Methods: The National Inpatient Sample (NIS) was queried between 2010 and 2015 for unplanned admissions among adults with a primary diagnosis of diverticulitis. We used a proportional hazards regression to estimate the hazard of failed non-operative management from multiple clinical covariates, measured as the number of inpatient days from admission until colonic resection. We also evaluated patients who received percutaneous drainage, to investigate whether this was associated with decreasing the failure rate of non-operative management. Results: A total of 830,993 discharges over the study period, of whom 83,628 (10.1%) underwent operative resection during the hospitalization, and 35,796 (4.3%) patients underwent percutaneous drainage. Half of all operations occurred by hospital day 1. Among patients treated with percutaneous drainage, 11% went on to require operative intervention. The presence of a peritoneal abscess (HR 3.20, P <.01) and sepsis (HR 4.16, P <.01) were the strongest predictors of failing non-operative management. Among the subset of patients with percutaneous drains, the mean time from admission to drain placement was 2.3 days. Conclusion: Overall 10.1% of unplanned admissions for diverticulitis result in inpatient operative resection, most of which occurred on the day of admission. Percutaneous drainage was associated with an 11% operative rate.