Table 2

Expertise-based randomized controlled trials identified after systematic literature search of MEDLINE and EMBASE

Trial	Specialty	Intervention	No. of participants and surgeons	Criteria for expertise
Finkemeier et al.29	Orthopedics	Nail insertion with reaming v. without reaming	94 participants 6 surgeons	NR
Phillips et al.30	Orthopedics	Open reduction and internal fixation v. closed cast treatment	138 participants 2 surgeons	NR
Machler et al.31	Cardiac	Mini aortic valve surgery (2 surgeons) v. conventional aortic valve (2 surgeons)	120 participants 4 surgeons	NR
Wihlborg et al.26	Orthopedics	Rydell 4-flanged nail v. Gouffon pins	200 participants 7 surgeons	No. of years of training and practice
Wyrsch et al.32	Orthopedics	ORIF of the tibia and fibula v. external fixation with or without limited internal fixation	39 participants 6 surgeons	Fellowship-trained trauma surgeons Experts
CABRI27	Cardiac surgery/cardiology	Coronary angioplasty v. CABG	1054 participants	High-volume centres Surgeon and physician performed > 500 procedures
RITA trial33	Cardiac surgery/cardiology	Coronary angioplasty v. CABG	1011 participants	High success and low complication rate
BARI28	Cardiac surgery/cardiology	Coronary angioplasty v. CABG	1829 participants	Yr of practice (3 yr) Outcome assessment “Majority of practice devoted to coronary artery surgery; most recent 100 consecutive primary, elective, isolated CABG operations with a mortality rate of no more than 2% (death within 30 days of procedure); and an MI rate of no more than 4%” No. of cases “as principal surgeon of 100 or more CABGs with internal mammary artery grafts” Number of cases “independent operator in more than 300 elective PTCA procedures, of which 100 were multivessel disease cases”
CORONARY23	Cardiac surgery	Off-pump v. On-pump CABG	4752 participants	Yr of practice (2 yr) No. of cases “more than 100 procedures involving the specific technique”
TOPKAT34 (ongoing) NCT01352247	Orthopedics	Total v. partial arthroplasty	500 participants	“Simple audit of participating surgeons’ routine practice will be undertaken” Appropriate training Yr of experience “at least 1 yr” No. of cases “have performed the operation at least 10 times in the past year”
HEALTH35 (ongoing) NCT00556842	Orthopedics	THA v. HA	1501 participants	No. of cases “Perform at least 50 procedures (either THA or HA) in their career” Annual load “at least 5 procedures per year”
NExT ERA36 (ongoing) NCT00358085	Vascular	Open v. endovascular repair for AAA	30 participants	Appropriate training “completion of a vascular residency at a credentialed academic centre, a period of study in a formal training program dedicated to acquiring endovascular expertise” or for open AAA “require completion of an accredited vascular surgery residency program No. of cases “experience with at least 60 previous EVAR procedures” or “at least 100 consecutive elective AAA repairs”

AAA = abdominal aortic aneurysm; CABG = coronary artery bypass grafting; EVAR = endovascular aneurysm repair; HA = hemiarthroplasty; MI = myocardial infarction; NR = not reported; ORIF = open reduction internal fixation; PTCA = percutaneous transluminal coronary angioplasty; THA = total hip arthroplasty.