The CABI Trial: an Unblinded Parallel Group Randomised Controlled Feasibility Trial of Long-Course Antibiotic Therapy (28 Days) Compared with Short Course (≤ 10 Days) in the Prevention of Relapse in Adults Treated for Complicated Intra-Abdominal Infection.

Purpose: Relapse after complicated intra-abdominal infection (cIAI) remains common after treatment. The optimal antibiotic treatment duration for cIAIs is uncertain, especially in cases where source control is not achieved. We hypothesised that in patients with cIAIs, regardless of source control intervention, there would be a lower relapse rate with long-course antibiotics (28 days) compared with short course (≤ 10 days).