Enhanced PeriOperative Care and Health protection programme for the prevention of surgical site infections after elective abdominal surgery (EPO2CH): statistical analysis plan of a randomised controlled multicentre superiority trial

Abstract

Background Surgical site infections (SSI) are frequent complications after elective abdominal surgery. We designed the Enhanced PeriOperative Care and Health Protection programme (EPO 2 CH) care bundle, comprising of intraoperative high fractional inspired oxygen; intraoperative goal-directed fluid therapy; active preoperative, intraoperative and postoperative warming; glucose control and treatment of hyperglycaemia (>\u200910\u2009mmol\u2009L −\u20091 ) in diabetics as well as non-diabetics; and wound irrigation before closure using an aqueous antiseptic. We hypothesise that EPO 2 CH added to standard care reduces the incidence of SSI compared to standard care alone for elective abdominal surgery. Methods This trial is designed as an open label, pragmatic randomised controlled parallel-group multicentre superiority trial. The primary endpoint is the incidence of SSI, defined by the Centers for Disease Control and prevention, within 30\u2009days after surgery. The incidence of SSI is assessed using the Dutch national complication register and medical chart review. Secondary endpoints include the SSI incidence within 90\u2009days, incidence of anastomotic leakage at 30 and 90\u2009days, the incidence of incisional hernia within 1\xa0year, mortality within 1\xa0year and 5\xa0years, quality of life, health and disability, and cost-effectiveness. Primarily, an intention-to-treat analysis will be performed to estimate the relative risk using a log binomial model. If not feasible, a logistic regression will be used to estimate the odds ratio. A per-protocol analysis will also be performed. Furthermore, the attributive effect of the distinct interventions will be explored. Discussion The results of the EPO 2 CH trial will determine if the EPO 2 CH bundle is effective to prevent SSI incidence for patients undergoing elective abdominal surgery. Details of the statistical analysis are described in this Statistical Analysis Plan (SAP). Trial registration Registration number: Dutch Trial Register Trial NL5572 . Registered on March 3, 2016. SAP version: V1.0, January 8, 2020. This SAP has been written based on study protocol V10.