title: A systematic review of Investigator Global Assessment (IGA) in atopic dermatitis (AD) trials: Many options, no standards.
abstract: BACKGROUND
  Investigators often use global assessments to provide a snapshot of overall disease severity in dermatologic clinical trials. Although easy to perform, the frequency of use and standardization of global assessments in studies of atopic dermatitis (AD) is unclear.
  
  
  OBJECTIVE
  We sought to assess the frequency, definitions, and methods of analysis of Investigator Global Assessment in randomized controlled trials of AD.
  
  
  METHODS
  We conducted a systematic review using all published randomized controlled trials of AD treatments in the Global Resource of Eczema Trials database (2000-2014). We determined the frequency of global scales application and defining features.
  
  
  RESULTS
  Among 317 trials identified, 101 trials (32%) used an investigator-performed global assessment as an outcome measure. There was large variability in global assessments between studies in nomenclature, scale size, definitions, outcome description, and analysis. Both static and dynamic scales were identified that ranged from 4- to 7-point scales. North American studies used global assessments more commonly than studies from other countries.
  
  
  CONCLUSIONS
  The search was restricted to the Global Resource of Eczema Trials database.
  
  
  CONCLUSIONS
  Global assessments are used frequently in studies of AD, but their complete lack of standardized definitions and implementation preclude any meaningful comparisons between studies, which in turn impedes data synthesis to inform clinical decision-making. Standardization is urgently required.
authors.affiliation: Division of Pediatrics, Nagoya Medical Center, Nagoya, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Futamura
authors.affiliation: Department of Dermatology, Oregon Health and Science University, Portland, Oregon.
authors.forename: Yael A
authors.initials: YA
authors.lastname: Leshem
authors.affiliation: Center of Evidence-based Dermatology, University of Nottingham, Nottingham, United Kingdom.
authors.forename: Kim S
authors.initials: KS
authors.lastname: Thomas
authors.affiliation: Center of Evidence-based Dermatology, University of Nottingham, Nottingham, United Kingdom.
authors.forename: Helen
authors.initials: H
authors.lastname: Nankervis
authors.affiliation: Center of Evidence-based Dermatology, University of Nottingham, Nottingham, United Kingdom.
authors.forename: Hywel C
authors.initials: HC
authors.lastname: Williams
authors.affiliation: Department of Dermatology, Oregon Health and Science University, Portland, Oregon. Electronic address: simpsone@ohsu.edu.
authors.forename: Eric L
authors.initials: EL
authors.lastname: Simpson
mesh_terms: D003876:Dermatitis, Atopic / Q000473:pathology* / Q000628:therapy; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000592:standards*; D012015:Reference Standards; D012107:Research Design / Q000592:standards*; D012720:Severity of Illness Index; D009626:Terminology as Topic
keywords: Investigator Global Assessment; atopic dermatitis; atopic eczema; global assessment; outcome measure; randomized controlled trial; severity; systematic review