title: Intra- and inter-rater reliability of digital image analysis for skin color measurement.
abstract: BACKGROUND
  We determined the intra- and inter-rater reliability of data from digital image color analysis between an expert and novice analyst.
  
  
  METHODS
  Following training, the expert and novice independently analyzed 210 randomly ordered images. Both analysts used Adobe(®) Photoshop lasso or color sampler tools based on the type of image file. After color correction with Pictocolor(®) in camera software, they recorded L*a*b* (L*=light/dark; a*=red/green; b*=yellow/blue) color values for all skin sites. We computed intra-rater and inter-rater agreement within anatomical region, color value (L*, a*, b*), and technique (lasso, color sampler) using a series of one-way intra-class correlation coefficients (ICCs).
  
  
  RESULTS
  Results of ICCs for intra-rater agreement showed high levels of internal consistency reliability within each rater for the lasso technique (ICC ≥ 0.99) and somewhat lower, yet acceptable, level of agreement for the color sampler technique (ICC = 0.91 for expert, ICC = 0.81 for novice). Skin L*, skin b*, and labia L* values reached the highest level of agreement (ICC ≥ 0.92) and skin a*, labia b*, and vaginal wall b* were the lowest (ICC ≥ 0.64).
  
  
  CONCLUSIONS
  Data from novice analysts can achieve high levels of agreement with data from expert analysts with training and the use of a detailed, standard protocol.
authors.affiliation: Nursing, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Marilyn
authors.initials: M
authors.lastname: Sommers
authors.forename: Barbara
authors.initials: B
authors.lastname: Beacham
authors.forename: Rachel
authors.initials: R
authors.lastname: Baker
authors.forename: Jamison
authors.initials: J
authors.lastname: Fargo
mesh_terms: D003075:Coitus; D003116:Color; D003124:Colorimetry / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data*; D016208:Databases, Factual; D003880:Dermatology / Q000295:instrumentation* / Q000592:standards / Q000706:statistics & numerical data; D005260:Female; D005554:Forensic Medicine / Q000295:instrumentation* / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods / Q000592:standards* / Q000706:statistics & numerical data*; D008297:Male; D015588:Observer Variation; D011902:Rape; D012015:Reference Standards; D015203:Reproducibility of Results; D012867:Skin; D014621:Vagina; D014844:Vulva
keywords: digital image analysis; image analysis; inter-rater reliability; protocols; skin color; skin imaging
references.citation: J Med Invest. 1998 Feb;44(3-4):121-6
references.pmid: 9597799
references.citation: Nat Genet. 2004 Nov;36(11 Suppl):S54-60
references.pmid: 15508005
references.citation: Skin Res Technol. 2009 May;15(2):180-6
references.pmid: 19622128
references.citation: Skin Res Technol. 2009 Feb;15(1):24-34
references.pmid: 19152575
references.citation: Photochem Photobiol. 1983 Jun;37(6):643-8
references.pmid: 6611670
references.citation: Skin Res Technol. 2000 Nov;6(4):230-238
references.pmid: 11428962
references.citation: Am J Orthod Dentofacial Orthop. 2009 Mar;135(3):276.e1-12; discussion 276-7
references.pmid: 19268820
references.citation: Pigment Cell Res. 2002 Apr;15(2):119-26
references.pmid: 11936269
references.citation: Am J Phys Anthropol. 2007;Suppl 45:85-105
references.pmid: 18046745
references.citation: J Obstet Gynecol Neonatal Nurs. 2008 May-Jun;37(3):282-9
references.pmid: 18507599
references.citation: Am J Emerg Med. 2008 Oct;26(8):857-66
references.pmid: 18926341
references.citation: Skin Res Technol. 2009 May;15(2):200-13
references.pmid: 19416467
references.citation: Australas J Dermatol. 2003 Feb;44(1):19-27
references.pmid: 12581077
references.citation: Int J Cosmet Sci. 1991 Aug;13(4):191-208
references.pmid: 19291061
references.citation: Plast Reconstr Surg. 2000 Nov;106(6):1366-72; discussion 1373-4
references.pmid: 11083571
references.citation: Anesth Analg. 1999 May;88(5):1131-6
references.pmid: 10320183
references.citation: J Forensic Nurs. 2009;5(4):191-200
references.pmid: 19947958
references.citation: Skin Res Technol. 2011 Aug;17(3):348-52
references.pmid: 21342293