External validation of the Oakland Score to assess safe hospital discharge among adult patients with acute lower gastrointestinal bleeding in a single New Zealand Centre

Background: Acute lower gastrointestinal bleeding (LGIB) is a common reason for hospital admission. However, the majority resolve spontaneously and only a minority require inpatient intervention. We aimed to describe the epidemiology and aetiology of acute LGIB admissions in our institution. We also aimed to validate the Oakland Score, which can identify patients at low risk of adverse outcome from LGIB, in our population and determine the proportion who could have safely avoided admission.Methods: Using the prospective, validated Otago Clinical Audit database (DIVA), we searched for adult patients admitted to Dunedin Hospital with a primary diagnosis of LGIB between January 2013 and December 2020. We retrieved data to calculate the Oakland Score and details of inpatient treatment from the electronic patient record. We excluded patients admitted electively, admissions related to inflammatory bowel disease, and those with upper gastrointestinal bleeding.Results: We identified 761 patients of which 501 met inclusion criteria (56% male, median age 76 years, 82% NZ European). Overall, 72% were managed with observation or diagnostic endoscopy, 32% received blood products, and 7% required haemostatic intervention to control bleeding. The area under the receiver operating characteristic curve for the Oakland Score was 0.85 (95% CI, 0.81-0.89). A cut-off score of <= 10 predicted a 95% probability of safely avoiding admission. This equates to saving 30 bed-days annually.Conclusion: The majority of patients admitted with LGIB are managed conservatively. The Oakland Score could be used as a stratification tool to safely reduce the admission rate.