Ambulatory management of acute uncomplicated diverticulitis (AmbUDiv study): a multicentre, propensity score matching study.

Introduction: Recent studies have suggested that ambulatory management is feasible for acute uncomplicated diverticulitis (AUD); however, there is still no consensus regarding the most appropriate management settings. This study presents a multi-centre experience of managing patients presenting with AUD, specifically focusing on clinical outcomes and comparing ambulatory treatment with in-patient management.

Methods: A retrospective multi-centre study was conducted across four hospitals in the UK and included all adult patients with computed tomography (CT) confirmed (Hinchey grade 1a) acute diverticulitis over a 12-month period (January - December 2022). Patient medical records were followed up for 1-year post-index episode, and outcomes were compared between those treated through the ambulatory pathway versus inpatient treatment using 1:1 propensity score matching (PSM). All statistical analysis was performed using the R Foundation for Statistical Computing, version 4.4.

Results: A total of 348 patients with Hinchey 1a acute diverticulitis were included (260 in-patients; 88 ambulatory pathway), of which nearly a third (31.3%) had a recurrent disease. Inpatient management was dominant (74.7%), with a median of 3 days of hospital stay. PSM resulted in 172 patients equally divided between the two care settings. Ambulatory management was associated with a lower readmission rate (P = 0.02 before PSM, P = 0.08 after PSM), comparable surgical (P = 0.57 before PSM, 0% in both groups after PSM) and radiological interventions (P = 0.99 before and after PSM) within one year. In both matched and non-matched groups, a strong association between readmissions and inpatient management was noted in univariate analysis (P = 0.03 before PSM, P = 0.04 after PSM) and multivariate analysis (P = 0.02 before PSM, P = 0.03 after PSM).

Conclusion: Our study supports the safety and efficacy of managing patients with AUD through a well-designed ambulatory care pathway. In particular, hospital re-admission rates are lower and other outcomes are non-inferior to in-patient treatment. This has implications for substantial cost-savings and better utilisation of limited healthcare resources.