3Neudecker J, Raue W, Schwenk W. High correlation but inadequate point-to-point agreement, between conventional mechanical and electron- ical visual analogue scale for assessment of acute postoperative pain after general surgerty [ J ]. Acute pain,2006,8 (4) : 175 - 180.
4Bailey B, Gravel J, Daoust R. Reliability of the visual analog scale in children with acute pain in the emergency department [ J ]. Pain, 2012, 153(4) :839 -842.