Drivers of cost after surgical and medical therapy for chronic ulcerative colitis: a nested case-cohort study in Olmsted County, Minnesota.

Background: We previously reported the costs associated with surgery for chronic ulcerative colitis in the Olmsted County population and found that direct medical costs after surgery were significantly reduced compared with before surgery. However, in that study, costs associated with chronic medical therapy for ulcerative colitis were not assessed in nonsurgical patients.

Objective: To gain insight into the drivers of costs of treatment for chronic ulcerative colitis, we assessed direct costs after surgical and medical therapy in 120 patients in the Rochester Epidemiology Project database.

Methods: A cohort of 60 patients who recovered from surgery for ulcerative colitis from 1988 to 2006 were 1:1 matched by age, sex, and referent year to medically managed patients. Direct health care costs were estimated from an institutional database, and observed cost differences over a 2-year period were calculated. Statistical significance was assessed by paired t tests and bootstrapping; mean costs are adjusted 2009 constant dollars.

Results: Two-year direct health care costs in the surgical and medical cohorts were $10,328 vs $6,586 (p = 0.19). In the surgical cohort, Brooke ileostomy patients were observed to have higher costs than patients with ileal pouches ([INCREMENT]$8187, p = 0.04), and after ileal pouch, pouchitis was associated with increased costs ([INCREMENT]$12,763, p < 0.01). In the medical cohort, disease extent ([INCREMENT]$6059, p = 0.04) but not disease severity was associated with increased costs.

Limitations: This study was limited by the relatively small population size and by its performance in a county with a tertiary referral center.

Conclusions: Before the introduction of biologic therapies for ulcerative colitis, patients were observed to have similar health care costs after surgical and medical therapy. In medically treated patients, disease extent was associated with increased costs, whereas in surgically treated patients, permanent ileostomy and pouchitis were observed to be associated with increased costs.