Reference method for digital surface measurement of target lesions in vitiligo: a comparative analysis.
Journal
The British journal of dermatology
ISSN: 1365-2133
Titre abrégé: Br J Dermatol
Pays: England
ID NLM: 0004041
Informations de publication
Date de publication:
05 2019
05 2019
Historique:
accepted:
07
09
2018
pubmed:
13
9
2018
medline:
1
8
2020
entrez:
13
9
2018
Statut:
ppublish
Résumé
Objective measurement of target lesions in vitiligo is important for clinical practice and trials, yet no preferred tool has been defined. Reported digital tools have shortcomings related to feasibility aspects and often lack information on validity, reliability and responsiveness. Moreover, studies are not yet based on ultraviolet (UV) photography. To assess the reliability, validity and feasibility of two functions in ImageJ for measurement of target lesions, based on three different types of images including UV pictures. Planimetric measurements were performed on photographs with and without UV, and lesion contours on transparent sheets of 52 vitiligo lesions from 10 patients with vitiligo. The ImageJ functions 'wand' and 'threshold' were used by three and four assessors, respectively. Inter- and intrarater reliability, hypothesis testing for construct validity, and feasibility were evaluated. The inter- and intrarater reliability for the 'wand' and 'threshold' functions were excellent [intraclass correlation coefficient (ICC) > 0·9] for measurement on pictures (with or without UV). The highest agreement (ICC > 0·95) and lowest variance were obtained for measurements on transparent sheets. All four hypotheses for construct validity were confirmed for all measurements. Overall, all measurement methods scored satisfactorily for user-friendliness. However, measurements on transparent sheets were preferred and the completion time was significantly faster. This study confirmed the reliability, validity and feasibility of two functions in ImageJ to measure target lesions in vitiligo. Based on the feasibility and included three-dimensional aspects, transparent sheets measured with the ImageJ 'wand' function can be proposed for future trials as a reference method to investigate the criterion validity of other digital instruments.
Sections du résumé
BACKGROUND
Objective measurement of target lesions in vitiligo is important for clinical practice and trials, yet no preferred tool has been defined. Reported digital tools have shortcomings related to feasibility aspects and often lack information on validity, reliability and responsiveness. Moreover, studies are not yet based on ultraviolet (UV) photography.
OBJECTIVES
To assess the reliability, validity and feasibility of two functions in ImageJ for measurement of target lesions, based on three different types of images including UV pictures.
METHODS
Planimetric measurements were performed on photographs with and without UV, and lesion contours on transparent sheets of 52 vitiligo lesions from 10 patients with vitiligo. The ImageJ functions 'wand' and 'threshold' were used by three and four assessors, respectively. Inter- and intrarater reliability, hypothesis testing for construct validity, and feasibility were evaluated.
RESULTS
The inter- and intrarater reliability for the 'wand' and 'threshold' functions were excellent [intraclass correlation coefficient (ICC) > 0·9] for measurement on pictures (with or without UV). The highest agreement (ICC > 0·95) and lowest variance were obtained for measurements on transparent sheets. All four hypotheses for construct validity were confirmed for all measurements. Overall, all measurement methods scored satisfactorily for user-friendliness. However, measurements on transparent sheets were preferred and the completion time was significantly faster.
CONCLUSIONS
This study confirmed the reliability, validity and feasibility of two functions in ImageJ to measure target lesions in vitiligo. Based on the feasibility and included three-dimensional aspects, transparent sheets measured with the ImageJ 'wand' function can be proposed for future trials as a reference method to investigate the criterion validity of other digital instruments.
Types de publication
Comparative Study
Journal Article
Validation Study
Langues
eng
Sous-ensembles de citation
IM
Pagination
1198-1205Commentaires et corrections
Type : CommentIn
Informations de copyright
© 2018 British Association of Dermatologists.