title: Faces scales for the measurement of postoperative pain intensity in children following minor surgery.
abstract: OBJECTIVE
  Faces scales are commonly used to obtain self-reports of pain intensity from children. Previous research using hypothetical vignettes and pain following venepuncture has found differences in children's pain ratings as a function of the type of faces scale used. The purpose of the present study was to determine whether scales beginning with a smiling rather than neutral "no pain" face would produce higher ratings in the assessment of postoperative pain intensity in children and to compare ratings using different faces scales to those reported with an additional independent measure of pain intensity.
  
  
  METHODS
  Participants were 78 children between the ages of 5 and 13 years undergoing surgery, one of their parents, and their postoperative care nurse. Following surgery, children were asked to provide a rating of their current pain intensity using a set of 5 successively administered faces scales and the Colored Analog Scale (CAS). Parents and nurses provided independent ratings using the same measures.
  
  
  RESULTS
  Results showed that parents and nurses rated significantly more pain when using scales with a smiling rather than a neutral "no pain" face. This pattern was not as clear for the children's ratings, although their highest ratings were provided when using a smiling "no pain" faces scale. Children's and nurses' ratings on the CAS were generally more similar to their ratings using scales with neutral "no pain" faces, whereas parents' CAS ratings tended to fall in between ratings provided on the smiling and neutral "no pain" faces scales. Scale preference, age and sex differences in pain ratings, and child-parent-nurse agreement in pain ratings are also examined.
  
  
  CONCLUSIONS
  Children's and parents' ratings of postoperative pain intensity are influenced by the presence of a smiling "no pain" face at the beginning of faces scales, with such scales producing significantly higher ratings than scales with neutral "no pain" faces. Ratings on the independent CAS measure were more comparable to those provided on faces scales with neutral "no pain" faces. Nurses are also susceptible to the influencing effect of a smiling face at the beginning of a faces scale.
authors.affiliation: Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada. christine.chambers@dal.ca
authors.forename: Christine T
authors.initials: CT
authors.lastname: Chambers
authors.forename: Janine
authors.initials: J
authors.lastname: Hardial
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Craig
authors.forename: Colleen
authors.initials: C
authors.lastname: Court
authors.forename: Carolyne
authors.initials: C
authors.lastname: Montgomery
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005260:Female; D006801:Humans; D008297:Male; D009726:Nurses / Q000523:psychology; D015588:Observer Variation; D010147:Pain Measurement; D010149:Postoperative Pain / Q000175:diagnosis* / Q000523:psychology; D010290:Parents / Q000523:psychology; D015203:Reproducibility of Results