Roles of evidence synthesis studies and evidence-based clinical practice guidelines in pediatric perioperative outcomes research

A randomized controlled trial (RCT) is generally considered to provide high-quality evidence for addressing a research hypothesis in clinical research [1, 2], such as trials comparing different fasting periods evaluated by ultrasound, or comparison of supraclavicular versus costoclavicular brachial plexus blocks [3‐8]. However, many RCTs in anesthesiology are known to be fragile, mainly due to small number of participants and low outcome event rates [9, 10]. The fragility index (FI) is used to assess the robustness of RCT results, measuring the minimum number of patients whose result would have to change from a non-event to an event in order to convert a result from statistically significant to nonsignificant—a smaller FI indicates a less robust result [9, 11]. Hayes et al. recently reported that the median FI in pediatric anesthesiology is 3, indicating RCTs in pediatric anesthesiology are highly fragile, and that many pediatric anesthesiology trials were underpowered [9, 11]. One way to mitigate the limitations of an underpowered RCT is to conduct an evidence synthesis study by quantitatively pooling results from multiple RCTs to enhance statistical power. …