“…Several studies did not specify the operative procedure during which the monitoring was performed [6,16,22,23], thus rendering the interpretation of emotional stress and especially physical demands impossible. Also, the number of participants-surgeons included in these studies was relatively small (two to 12; median, eight) [6,7,9,11,12,15,16,22,23,30], diminishing the power of the studies and introducing the possibility of selection bias.…”