Canadian infants presenting with Brief Resolved Unexplained Events (BRUEs) and validation of clinical prediction rules for risk stratification: a protocol for a multicentre, retrospective cohort study.

introductionBrief Resolved Unexplained Events (BRUEs) are a common presentation among infants. While most of these events are benign and self-limited, guidelines published by the American Academy of Pediatrics inaccurately identify many patients as higher-risk of a serious underlying aetiology (positive predictive value 5%). Recently, new clinical prediction rules have been derived to more accurately stratify patients. This data were however geographically limited to the USA, with no large studies to date assessing the BRUE population in a different healthcare setting. The study's aim is to describe the clinical management and outcomes of infants presenting to Canadian hospitals with BRUEs and to externally validate the BRUE clinical prediction rules in identified cases. METHODS AND ANALYSIS: This is a multicentre retrospective study, conducted within the Canadian Paediatric Inpatient Research Network (PIRN). Infants (<1 year) presenting with a BRUE at one of 11 Canadian paediatric centres between 1 January 2017 and 31 December 2021 will be included. Eligible patients will be identified using diagnostic codes.The primary outcome will be the presence of a serious underlying illness. Secondary outcomes will include BRUE recurrence and length of hospital stay. We will describe the rates of hospital admissions and whether hospitalisation was associated with an earlier diagnosis or treatment. Variation across Canadian hospitals will be assessed using intraclass correlation coefficient. To validate the newly developed clinical prediction rule, measures of goodness of fit will be evaluated. For this validation, a sample size of 1182 is required to provide a power of 80% to detect patients with a serious underlying illness with a significance level of 5%. ETHICS AND DISSEMINATION: Ethics approval has been granted by the UBC Children's and Women's Research Board (H21-02357). The results of this study will be disseminated as peer-reviewed manuscripts and presentations at national and international conferences.