title: Functional Reading Independence (FRI) Index: A New Patient-Reported Outcome Measure for Patients With Geographic Atrophy.
abstract: To develop and validate the Functional Reading Independence (FRI) Index, a new patient-reported outcome measure assessing reading activities in individuals with geographic atrophy (GA) due to age-related macular degeneration.
  
  
  
  The Index was developed through expert consultation and qualitative patient interviews. Reliability, validity, and responsiveness were tested with data from the Mahalo study (NCT01229215) of lampalizumab in patients with GA.
  
  
  
  Qualitative interviews (n = 40) yielded a 10-item FRI Index, which was refined to seven items in quantitative testing (n = 100). Strong internal consistency (marginal reliability = 0.90) and reproducibility (intraclass correlation coefficient = 0.86) were shown. Known-group validity testing for baseline mean FRI Index scores showed differences (mean [SD]) between patients with Minnesota Low-Vision Reading test reading speed ≥80 vs. <80 words per minute (3.0 [0.7] vs. 1.9 [0.7]; P < 0.001), and between patients above vs. below median values on the National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25) score (2.9 [0.7] vs. 2.1 [0.8]; P < 0.001). Convergent validity with binocular measures was strong (Spearman's correlation = 0.72 for reading speed, 0.66 for NEI-VFQ-25). Analysis of sensitivity to change revealed mean FRI Index score changes for patients with GA lesion size growth ≥2.5 mm2/18 months of -0.41 (0.70) vs. -0.13 (0.61) for patients with lesion growth <2.5 mm2/18 months (P = 0.07).
  
  
  
  The FRI Index demonstrated good reliability and validity in patients with GA. Further study in a broader GA population is warranted to confirm responsiveness.
authors.affiliation: Evidera, Bethesda, Maryland, United States.
authors.forename: Miriam
authors.initials: M
authors.lastname: Kimel
authors.affiliation: Evidera, Bethesda, Maryland, United States.
authors.forename: Nancy Kline
authors.initials: NK
authors.lastname: Leidy
authors.affiliation: Genentech, Inc., South San Francisco, California, United States.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tschosik
authors.affiliation: CMD Consulting, Inc., Sandy, Utah, United States.
authors.forename: Chantal
authors.initials: C
authors.lastname: Dolan
authors.affiliation: Centre Hospitalier Intercommunal, Créteil, France.
authors.forename: Eric H
authors.initials: EH
authors.lastname: Souied
authors.affiliation: USC Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States.
authors.forename: Rohit
authors.initials: R
authors.lastname: Varma
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.
authors.forename: Neil M
authors.initials: NM
authors.lastname: Bressler
mesh_terms: D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D057092:Geographic Atrophy / Q000188:drug therapy / Q000503:physiopathology*; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000008:administration & dosage*; D000071066:Patient Reported Outcome Measures; D011446:Prospective Studies; D011594:Psychometrics / Q000379:methods; D011788:Quality of Life; D011932:Reading; D018434:Sickness Impact Profile; D016037:Single-Blind Method; D014792:Visual Acuity / Q000502:physiology*
chemical_list: D007140:Immunoglobulin Fab Fragments; C000603963:lampalizumab