Content Validity and Internal Consistency
The second version of the instrument was sent out to the local higher surgical trainees and consultant trainers of various surgical subspecialties. They were asked to review the instrument and determine how relevant each individual item is when assessing the theatre learning environment. Each item was scored on a Likert scale of 1 (not relevant, can be excluded from the instrument) to 4 (highly relevant, must be included in the instrument). Two content validity index values (CVI) of each item were independently derived from the scores in the trainee and trainer group. Seven higher surgical trainees and seven consultant trainers were involved in this process, the acceptable CVI values of panel of this size is 0.83 (11). Only items which have reached a cut-off CVI score in the trainee group were included in the third version of the instrument. CVI scores in the trainer group were used to compare and contrast with the scores in the trainee group.
The third version of the instrument was sent out to the local higher surgical trainees. They were asked to complete the questionnaire regarding their training experience at their current rotation. Each item was scored on a Likert scale of 1 (strongly disagree) to 4 (strongly agree). The scores are reversed in negatively worded items. Cronbach’s α was derived from these responses for the overall instrument, as well as the three subdomains that the instrument aims to measure: trainer support and supervision, operating opportunities, and theatre atmosphere.