Research Article
Issue Date: May 08, 2019
Published Online: May 08, 2019
Updated: May 09, 2019
Measurement Validity of the Low Vision Independence Measure (LVIM)
Author Affiliations
  • Theresa M. Smith, PhD, OTR, CLVT, is Associate Professor, School of Occupational Therapy, Texas Woman’s University, Houston; tsmith12@twu.edu. At the time of this research, she was Associate Professor, Department of Occupational Therapy, University of Texas Medical Branch, Galveston.
  • Theresa M. Smith, PhD, OTR, CLVT, is Associate Professor, School of Occupational Therapy, Texas Woman’s University, Houston; tsmith12@twu.edu. At the time of this research, she was Associate Professor, Department of Occupational Therapy, University of Texas Medical Branch, Galveston.
  • Theresa M. Smith, PhD, OTR, CLVT, is Associate Professor, School of Occupational Therapy, Texas Woman’s University, Houston; tsmith12@twu.edu. At the time of this research, she was Associate Professor, Department of Occupational Therapy, University of Texas Medical Branch, Galveston.
  • Theresa M. Smith, PhD, OTR, CLVT, is Associate Professor, School of Occupational Therapy, Texas Woman’s University, Houston; tsmith12@twu.edu. At the time of this research, she was Associate Professor, Department of Occupational Therapy, University of Texas Medical Branch, Galveston.
Article Information
Vision / Research Articles
Research Article   |   May 08, 2019
Measurement Validity of the Low Vision Independence Measure (LVIM)
American Journal of Occupational Therapy, 5 2019, Vol. 73, 7303205070. https://doi.org/10.5014/ajot.2019.031070
American Journal of Occupational Therapy, 5 2019, Vol. 73, 7303205070. https://doi.org/10.5014/ajot.2019.031070
Abstract

OBJECTIVE. This study’s objective was to test the psychometrics of Smith’s (2013)  Low Vision Independence Measure (LVIM) using the Rasch model.

METHOD. A cohort design was used with 93 participants receiving occupational therapy for low vision. Confirmatory factor analysis (CFA) with a parceling approach was used to test the LVIM factors and Rasch analysis to examine item-level psychometrics.

RESULTS. Participants’ average age was 78.9 yr (standard deviation = 12.1), and the majority were female (72.8%) with macular degeneration (62.3%). The CFA revealed two measurement factors: visual field or scotoma (n = 28) and visual acuity (n = 24). We removed six misfitting items, and the two factors of the revised LVIM demonstrated good rating scale function, good internal consistency (person reliability: visual field, .87; visual acuity, .90), good precision (person strata: visual field, 3.91; visual acuity, 4.40), no ceiling or floor effects, and no differential item functioning.

CONCLUSION. The revised LVIM demonstrates good psychometrics on the Rasch model and can be used as a valid outcome measure in low vision rehabilitation.