Optimising the treatment for uncomplicated acute appendicitis (OPTIMA trial): a protocol for a multicentre, randomised, double-blinded placebo-controlled study

Introduction Emerging evidence has shown that an antibiotic first strategy is a viable treatment option for uncomplicated acute appendicitis (AA). Although there has recently been an interest and increase in the use of antibiotics as the primary strategy for treating uncomplicated AA, there is no consensus regarding the optimum antibiotic regimen. In particular, the long-term outcomes of different antibiotic regimens, such as the recurrence rate, still lack evidence. Given that the flora of the appendix is mainly anaerobic bacteria, we hypothesised that antianaerobe regimens could decrease the recurrence rate compared with those that did not include antianaerobic antibiotics. Methods and analysis The OPTIMA(Optimising the treatment for uncomplicated acute appendicitis) trial is a multicentre, double-blinded placebo-controlled superiority randomised study aimed to evaluate the role of antianaerobic antibiotics in the resolution of uncomplicated AA. Patients (18-65 years) with uncomplicated AA (without gangrenous, perforated appendicitis, appendiceal abscess, or appendiceal fecaliths) are eligible for inclusion. The primary endpoint of this study is the success rate of the treatment, defined as the resolution of AA resulting in discharge from the hospital without surgical intervention and recurrent symptoms within one year. Secondary endpoints include mortality, postintervention complications, recurrent symptoms up to one year after treatment, hospital stay, sick leave, treatment cost, pain symptom scores and quality of life. Data are reported as the number of cases (%), median (range) and relative risk, which will be analysed using the Mann-Whitney U test or chi(2) test, as appropriate. P-valueEthics and dissemination The protocol has been approved by the Ethics Committee of Jinling Hospital on 13 November 2018 (2018NZKY-027-01). The trial findings will be published in peer-reviewed journals.