Table 5 Examples of published randomised controlled trials (RCTs) in surgery requiring different amounts of standardisation of the interventions
From: Interventions in randomised controlled trials in surgery: issues to consider during trial design
Factors contributing to the level of control required | Example of RCTs requiring less standardisation | Example of RCTs requiring more standardisation |
|---|---|---|
Scope of the trial | Comparison of surgery and medical therapy for treatment of gastro-oesophageal reflux disease [26] | Carotid artery stenting compared with endarterectomy in patients with carotid stenosis [27] |
Pragmatic versus explanatory approach to design | Pragmatic: The trial aimed to establish the effectiveness of the interventions in practice | Explanatory: The trial aimed to establish the safety and efficacy of the ‘new’ intervention (stenting) under ideal conditions |
Stage of innovation of the intervention | Open versus minimally invasive surgery for colorectal cancer [28] | Endovascular versus open repair of abdominal aortic aneurysms [29] |
Established versus new innovation | Established: Open colorectal surgery is routinely undertaken by many operators in clinical practice and the main steps are already known | Early: Endovascular aneurysm repair is a relatively new technique and the main steps are less well known |
Complexity of the intervention | Effect of an implantable gentamicin-collagen sponge on sternal wound infections following cardiac surgery [30] | Extracranial-intracranial bypass surgery for stroke prevention in hemodynamic cerebral ischemia [31] |
Few components and low technical difficulty versus multiple components or requiring highly complex skills | Low complexity: Intervention involves placing an antibiotic impregnated sponge beneath patients’ wounds prior to closure | High complexity: Intervention is complex involving multiple components, high levels of technical expertise and multiple concomitant interventions |
Nature of interventions being compared | Amoxicillin plus clavulanic acid versus appendicectomy for treatment of acute uncomplicated appendicitis [32] | Laparoscopic gastric bypass versus laparoscopic duodenal switch for super obesity [33] |
Surgical and non-surgical intervention, or different surgical interventions | Surgery versus non-surgery: Distinction between trial groups is straightforward because of the very different nature of interventions | Surgery versus surgery: Distinction between the two groups is less straightforward because both interventions are surgical |