title: A multirater validation study to assess the reliability of acne lesion counting.
abstract: BACKGROUND
  Despite widespread use of acne lesion counting, little has been published on its reliability, particularly for multiple raters.
  
  
  OBJECTIVE
  Our purpose was to assess reliability of acne lesion counting with the use of a five-segment facial template.
  
  
  METHODS
  After training, 12 raters each evaluated 12 patients in randomized order, in the morning and again in the afternoon, and recorded counts for different types of lesions on a five-segment facial template.
  
  
  RESULTS
  Individual raters could reproduce their total lesion counts (reliability estimates, 0.81 to 0.97). Variability between raters was high, and overall reliability estimated across raters was 0.61. For a subgroup of commonly trained raters, overall reliability was higher (0.80).
  
  
  CONCLUSIONS
  The reliability of acne lesion counting is excellent when performed by the same trained rater over time. The high variability between raters appears to be reduced by standardized training. Because fewer lesions are counted with less variation, use of a template may have contributed to the high within-rater reliability.
authors.affiliation: Dermatology Research Associates, Cincinnati, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Lucky
authors.forename: B L
authors.initials: BL
authors.lastname: Barber
authors.forename: C J
authors.initials: CJ
authors.lastname: Girman
authors.forename: J
authors.initials: J
authors.lastname: Williams
authors.forename: J
authors.initials: J
authors.lastname: Ratterman
authors.forename: J
authors.initials: J
authors.lastname: Waldstreicher
mesh_terms: D000152:Acne Vulgaris / Q000473:pathology*; D000293:Adolescent; D000704:Analysis of Variance; D003880:Dermatology / Q000295:instrumentation / Q000706:statistics & numerical data; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012867:Skin / Q000473:pathology