Randomised controlled trials done in the past few decades show that conventional surgical randomised controlled trials are feasible. However, surgical research is still dominated by observational studies,19,21
and general surgery interventions are half as likely to be based on the results of randomised controlled trials as medical interventions.22,23
To investigate the feasibility of the expertise based randomised controlled trial in areas in which both designs are an option we searched three electronic bibliographic databases: MEDLINE (1966 to September Week 2 2003), EBM Reviews—Cochrane Central Register of Controlled Trials (issue 2, 2003), and EMBASE (1980 to 2003 Week 38). Complete listings of search strategies are available from the authors.
This search identified 162 citations, and two researchers independently reviewed each citation to determine if the report was a surgical expertise based randomised controlled trial. We contacted one of the trial authors in cases of disagreements. We identified five surgical expertise based randomised controlled trials that were conducted in an area in which both designs were a potential option.24-27
summaries the characteristics of these expertise based randomised controlled trials, showing that such trials are feasible in both emergency and elective surgery.
Surgical expertise based randomised controlled trials
Surgical expertise based randomised controlled trials may be more feasible than conventional randomised controlled trials. Surgeons may be more willing to participate in an expertise based randomised controlled trial because they have to perform only the procedure for which they have developed expertise. Furthermore, surgeons do not have to do a minimum number of operations with the unfamiliar intervention before participating in the trial. This is likely to appeal to both surgeons and investigators and could prevent delays in starting trials.
The feasibility of expertise based randomised controlled trials will be enhanced when an intermediary physician randomises patients before they are seen by the participating surgeon. For example, in trials of patients admitted to accident and emergency, a surgical resident or an emergency physician could randomise the patient. Expertise based randomised controlled trials may also work well in group practices. Some cardiac surgeons, for instance, have group practices and accept patients for surgery without assignment to a specific surgeon. Patients at such practices could be randomised into an expertise based randomised controlled trial when they are accepted for surgery. Greater practical experience with the expertise based design is needed to evaluate the effectiveness of these approaches to recruitment.
Enrolling patients into an expertise based randomised controlled trial may be more challenging after a patient has seen a specific surgeon because randomising such a patient to another surgeon may be awkward. Even under these circumstances, an expertise based randomised controlled trial may prove feasible. For instance, in the largest randomised trial of treatment for subarachnoid haemorrhage, in which 2143 patients were randomised to neurosurgical clipping versus endovascular coiling,29
patients were seen first by neurosurgeons, who then randomised them to neurosurgery or endovascular coiling by an interventional radiologist.
A potential challenge to undertaking an expertise based randomised controlled trial is that it is highly desirable to have surgeons from both treatment groups at all participating hospitals. This avoids the possible negative impact on recruitment resulting from patients having to travel to other hospitals and the potential confounding related to variations in non-surgical care in the different hospitals. If, in an expertise based randomised controlled trial, it is not possible to have surgeons from both treatment groups at all participating hospitals, the effect of centre is likely to vary depending on the nature of the procedure. The centre may not have an important effect for outpatient procedures, but the effect may be large for major inpatient procedures. For trials of major procedures, trialists will have to weigh the potential influence of differential expertise bias, surgeon unblinding, and differential crossover versus centre effect when deciding on the optimal trial design. The need to have two groups of surgeons on call presents a further challenge to undertaking expertise based randomised controlled trials of 24 hour acute surgical care.
A surgical expertise based randomised controlled trial must ensure satisfactory competence among the surgeons doing each procedure. Strategies to achieve this goal will include selecting qualified surgeons who have attained a specified level of post training experience, who fulfil requirements established by professional guidelines, or who have documented their expertise is at the plateau of the learning curve.