Direct costs of diverticulitis in a US managed care population

Objectives: To estimate the economic burden of diverticulitis in a large, real-world managed care population. Study Design: Retrospective cohort analysis. Methods: Insurance claims from 40 managed care plans covering 50 million lives were analyzed to identify diverticulitis patients aged >18 years with plan enrollment for >6 months before and >12 months after index diagnosis. We estimated resource utilization and both disease-related costs and all-cause costs (in 2009 US dollars) in patients with and without diverticulitis, matched 2:1 on age, sex, and plan enrollment. Cost data were adjusted for patient characteris-tics, preindex healthcare costs, and comorbidities. Results: In total, 36,624 diverticulitis patients and 73,248 matched controls were identified. In two-thirds of cases, the index diverticulitis diagnosis occurred in an outpatient setting, 22% occurred in the emergency department (ED), and 12% in hospital. Postindex hospitalization for any reason occurred in 41% of cases (vs 7% of controls; P <.001), regardless of diagnosis setting. Diverticulitis-related hospitalization occurred in 32% of cases. ED visits occurred in 53% of cases (vs 16% of controls; P <.001). Total adjusted disease-related cost per case was $5844, but varied by diagnosis setting ($11,772 for inpatient, $6355 for ED, and $4557 for outpatient). Mean adjusted all-cause hospitalization costs for cases and controls were $8918 and $1138, respectively (P <.001). Total adjusted all-cause costs were $19,627 in cases versus $6309 in controls (P <.001). Conclusions: Diverticulitis is associated with increased medical resource utilization, resulting in increased costs compared with matched patients without diverticulitis.