title: Reliability and validity of abbreviated surveys derived from the National Eye Institute Visual Function Questionnaire: the study of osteoporotic fractures.
abstract: OBJECTIVE
  To test the reliability and validity of questionnaires shortened from the National Eye Institute 25-item Vision Function Questionnaire (NEI VFQ-25).
  
  
  METHODS
  Cross-sectional, multicenter cohort study.
  
  
  METHODS
  Reliability was assessed by Cronbach alpha coefficients. Validity was evaluated by studying the association of vision-targeted quality-of-life composite scores with objective visual function measurements. A total of 5482 women between the ages of 65 and 100 years participated in the year-10 clinic visit in the Study of Osteoporotic Fractures (SOF). A total of 3631 women with complete data were included in the visual acuity (VA) and visual field (VF) analyses of the 9-item NEI VFQ (NEI VFQ-9), which is defined for those who care to drive, and a total of 5311 women with complete data were included in the VA and VF in the analyses of the 8-item NEI VFQ (NEI VFQ-8). To assess differences in prevalent eye diseases, which were ascertained for a random sample of SOF participants, 853 and 1237 women were included in the NEI VFQ-9 and the NEI VFQ-8 analyses, respectively.
  
  
  RESULTS
  The Cronbach alpha coefficient for the NEI VFQ-9 scale was 0.83, and that of the NEI VFQ-8 was 0.84. Using both questionnaires, women with VA worse than 20/40 had lower composite scores compared with those with VA of 20/40 or better (P < .001). Participants with mild, moderate, and severe binocular VF loss had lower composite scores compared with those with no binocular VF loss (P < .001). Compared with women without chronic eye diseases in both eyes, women with at least 1 chronic eye disease in at least 1 eye had lower composite scores.
  
  
  CONCLUSIONS
  Both questionnaires showed high reliability across items and validity with respect to clinical markers of eye disease. Future research should compare the properties of these shortened surveys with those of the NEI VFQ-25.
authors.affiliation: Jules Stein Eye Institute and the Department of Ophthalmology, David Geffen School of Medicine at University of California-Los Angeles, 100 Stein Plaza, Los Angeles, CA 90095-7004, USA.
authors.forename: Gergana
authors.initials: G
authors.lastname: Kodjebacheva
authors.forename: Anne L
authors.initials: AL
authors.lastname: Coleman
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Fei
authors.initials: F
authors.lastname: Yu
authors.forename: Katie L
authors.initials: KL
authors.lastname: Stone
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Pedula
authors.forename: Marc C
authors.initials: MC
authors.lastname: Hochberg
authors.forename: Carol M
authors.initials: CM
authors.lastname: Mangione
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005128:Eye Diseases / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D005598:Fractures, Spontaneous / Q000503:physiopathology; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D054554:National Eye Institute (U.S.); D015663:Osteoporosis, Postmenopausal / Q000503:physiopathology; D011446:Prospective Studies; D011788:Quality of Life; D015203:Reproducibility of Results; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014481:United States; D014792:Visual Acuity / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology