title: Evaluation of Cohen's cross-section trichometer for measuring hair quantity.
abstract: BACKGROUND
  Until now, there has been no reliable, simple method available for measuring hair quantity that is suitable in clinical practice. Recently, the cross-section trichometer by Cohen has been introduced. This study was designed to test its clinical utility.
  
  
  METHODS
  The hair mass index (HMI) is ratio of the cross-sectional area of an isolated bundle of hair and the premeasured area of skin from which it was taken using the trichometer device. The intra- and interobserver reproducibility of measurements at the same location and after relocation were evaluated.
  
  
  RESULTS
  For intraobserver reproducibility, the HMI ranged from 3 to 120 (mean difference .2, 95% confidence interval [CI] = -4.7-5.1, correlation coefficient [r] = .99. For interobserver reproducibility, the HMI ranged from 18 to 119 (mean difference -.4, 95% CI = -8,0-7,2, r = .98). With relocation, the HMI ranged from 2 to 113 (mean difference -1.0, 95% CI = -10.1-8.1, r = .97). Measurements took 5-10 minutes per area.
  
  
  CONCLUSIONS
  Measurements were simple to perform, and the data showed high reproducibility. The trichometer is a promising technology for hair quantity measurements and has multiple clinical and research applications.
authors.affiliation: Department of Medicine, University of Maastricht, Maastricht, The Netherlands. marij.hendriks@hotmail.com
authors.forename: Maria A E
authors.initials: MA
authors.lastname: Hendriks
authors.forename: Paulus A F
authors.initials: PA
authors.lastname: Geerts
authors.forename: Marcus W
authors.initials: MW
authors.lastname: Dercksen
authors.forename: Corina J G
authors.initials: CJ
authors.lastname: van den Hurk
authors.forename: Wim P M
authors.initials: WP
authors.lastname: Breed
mesh_terms: D006197:Hair / Q000033:anatomy & histology*; D006801:Humans; D015588:Observer Variation