title: Diagnostic Discrepancies in Retinopathy of Prematurity Classification.
abstract: To identify the most common areas for discrepancy in retinopathy of prematurity (ROP) classification between experts.
  
  
  
  Prospective cohort study.
  
  
  
  A total of 281 infants were identified as part of a multicenter, prospective, ROP cohort study from 7 participating centers. Each site had participating ophthalmologists who provided the clinical classification after routine examination using binocular indirect ophthalmoscopy (BIO) and obtained wide-angle retinal images, which were independently classified by 2 study experts.
  
  
  
  Wide-angle retinal images (RetCam; Clarity Medical Systems, Pleasanton, CA) were obtained from study subjects, and 2 experts evaluated each image using a secure web-based module. Image-based classifications for zone, stage, plus disease, and overall disease category (no ROP, mild ROP, type II or pre-plus, and type I) were compared between the 2 experts and with the clinical classification obtained by BIO.
  
  
  
  Inter-expert image-based agreement and image-based versus ophthalmoscopic diagnostic agreement using absolute agreement and weighted kappa statistic.
  
  
  
  A total of 1553 study eye examinations from 281 infants were included in the study. Experts disagreed on the stage classification in 620 of 1553 comparisons (40%), plus disease classification (including pre-plus) in 287 of 1553 comparisons (18%), zone in 117 of 1553 comparisons (8%), and overall ROP category in 618 of 1553 comparisons (40%). However, agreement for presence versus absence of type 1 disease was >95%. There were no differences between image-based and clinical classification except for zone III disease.
  
  
  
  The most common area of discrepancy in ROP classification is stage, although inter-expert agreement for clinically significant disease, such as presence versus absence of type 1 and type 2 disease, is high. There were no differences between image-based grading and clinical examination in the ability to detect clinically significant disease. This study provides additional evidence that image-based classification of ROP reliably detects clinically significant levels of ROP with high accuracy compared with the clinical examination.
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Campbell
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Ryan
authors.affiliation: Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, Oregon.
authors.forename: Emily
authors.initials: E
authors.lastname: Lore
authors.affiliation: Cognitive Systems Laboratory, Northeastern University, Boston, Massachusetts.
authors.forename: Peng
authors.initials: P
authors.lastname: Tian
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon.
authors.forename: Susan
authors.initials: S
authors.lastname: Ostmo
authors.affiliation: Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: Karyn
authors.initials: K
authors.lastname: Jonas
authors.affiliation: Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, University of Illinois at Chicago, Chicago, Illinois.
authors.forename: R V Paul
authors.initials: RVP
authors.lastname: Chan
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon; Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, Oregon. Electronic address: chiangm@ohsu.edu.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Chiang
mesh_terms: D015331:Cohort Studies; D003951:Diagnostic Errors; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D015588:Observer Variation; D009887:Ophthalmoscopy; D010781:Photography / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D012178:Retinopathy of Prematurity / Q000145:classification* / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D017216:Telemedicine / Q000379:methods