Introduction: Diverticulitis is a common diagnosis in the emergency department (ED). Outpatient management of diverticulitis is safe in selected patients, yet the rates of admission and surgical procedures following ED visits for diverticulitis are unknown, as are the predictive patient characteristics. Our goal is to describe trends in admission and surgical procedures following ED visits for diverticulitis, and to determine which patient characteristics predict admission.

Methods: We performed a cross-sectional descriptive analysis using data on ED visits from 2006-2011 to determine change in admission and surgical patterns over time. The Nationwide Emergency DepartmentSample database, a nationally representative administrative claims dataset, was used to analyze ED visits for diverticulitis. We included patients with a principal diagnosis of diverticulitis (ICD-9 codes562.11, 562.13). We analyzed the rate of admission and surgery in all admitted patients and in low-risk patients, defined as age <50 with no comorbidities (Elixhauser). We used hierarchical multivariate logistic regression to identify patient characteristics associated with admission for diverticulitis.

Results: From 2006 to 2011 ED visits for diverticulitis increased by 21.3% from 238,248 to 302,612, while the admission rate decreased from 55.7% to 48.5% (-7.2%, 95% CI [–7.78 to -6.62]; p<0.001 for trend). The admission rate among low-risk patients decreased from 35.2% in 2006 to 26.8% in 2011 (-8.4%, 95% CI [–9.6 to –7.2]; p<0.001 for trend). Admission for diverticulitis was independently associated with male gender, comorbid illnesses, higher income and commercial health insurance.The surgical rate decreased from 6.5% in 2006 to 4.7% in 2011 (-1.8%, 95% CI [–2.1 to –1.5]; p<0.001 for trend), and among low-risk patients decreased from 4.0% to 2.2% (- 1.8%, 95% CI [–4.5 to –1.7]; p<0.001 for trend).

Conclusion: From 2006 to 2011 ED visits for diverticulitis increased, while ED admission rates andsurgical rates declined, with comorbidity, sociodemographic factors predicting hospitalization. Future work should focus on determining if these differences reflect increased disease prevalence, increased diagnosis, or changes in management.