McClusky 2004.

Methods	Randomised clinical trial.
Participants	Country: United States of America. Number randomised: 12. Postrandomisation drop‐outs: not stated. Revised sample size: 12. Average age: not stated. Women: not stated. Inclusion criteria: 1. Surgical residents (postgraduate years 1 and 2).
Interventions	Participants were randomly assigned to two groups. Group 1: virtual reality training (n = 6). Group 2: no supplementary training (n = 6). Details of virtual reality training: 1. Minimally Invasive Surgical Trainer ‐ Virtual Reality trainer (MIST‐VR). 2. Expert established performance criterion levels on the manipulation diathermy task of the MIST‐VR.
Outcomes	The outcome reported was operating time.
Notes	Assessment: The participants performed a laparoscopic cholecystectomy each after the period of training.  We attempted to contact authors in October 2012. No replies were received.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: This information was not available.
Allocation concealment (selection bias)	Unclear risk	Comment: This information was not available.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Comment: It is impossible to blind the participants to the groups.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "Recordings were assessed by two blinded surgeon investigators" Comment: Although the video recording of the procedures was assessed by blinded observers, there is no information on whether any of the outcomes of interest for this review were assessed by observers blinded to the group of the participants.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: This information was not available.
Selective reporting (reporting bias)	High risk	Comment: Some important outcomes which will generally be assessed were not reported.
Source of funding bias	Unclear risk	Comment: This information was not available.