Date Presented 04/13/21
This study explored associations between health literacy and severity of visual impairment in older adults with age-related macular degeneration (AMD). The Short Test of Functional Health Literacy in Adults was used to assess health literacy for timed and untimed testing conditions. A one-way analysis of variance was used for analysis. Timed, 73% of participants had inadequate health literacy. Untimed, 100% of participants had adequate health literacy. All scores improved with the time limit removed. Time may be underrecognized factor of reading performance in older adults with AMD.
Primary Author and Speaker: Jennifer Fortuna
Contributing Authors: Tina Fletcher, Catherine Candler, and Karen Dunlap
PURPOSE: Comprehension of written text is influenced by skills in basic literacy (ability to read, write and interpret written text), the physical properties of text (font style and size, contrast, spacing) and the visual capacities of the reader. The match between these factors will determine how successfully text is read, processed and understood. The purpose of this study was to explore associations between functional health literacy level and severity category of visual impairment in older adults with age-related macular degeneration (AMD). The information obtained from this study is needed to address gaps in the literature and inform future research.
DESIGN: A between-subjects study design was employed to explore differences in functional health literacy across three severity categories of visual impairment (moderate, severe and profound). This study recruited a convenience sample of older adults with age-related macular degeneration (AMD) from one non-profit low vision clinic. Each participant was assigned to one severity category of visual impairment based on distance visual acuity. Results from a test of functional health literacy were compared to examine differences between severity categories.
METHOD: The Short Test of Functional Health Literacy in Adults (S-TOFHLA) was administered to measure functional health literacy levels (inadequate, marginal, adequate) in participants. Scores were recorded for timed (seven minute) and untimed testing conditions for comparison. A one-way analysis of variance (ANOVA) was used to determine differences between S-TOFHLA scores across severity categories of visual impairment. Separate analyses were conducted to compare the scores for timed and untimed testing conditions. The mean time required to complete the S-TOFHLA was calculated for each severity category. A value of p < .05 was used to determine statistical significance.
RESULTS: Fifteen participants met the inclusion criteria for this study. Five participants were assigned to each severity category resulting in three equal groups. Participant ages ranged from 67-96 with an average age of 86. Visual acuity ranged from 20/70 to 20/800. S-TOFHLA scores and related health literacy levels varied greatly by time condition. For the standard (seven minute) time condition, 73% of participants had inadequate health literacy; whereas, 27% had marginal health literacy. Results for the untimed condition found 100% of participants had adequate health literacy. Results of the ANOVA found no significant differences in S-TOFHLA scores between three severity categories for timed and untimed testing conditions. The severe category had the lowest mean S-TOFHLA score for both time conditions. This finding was unanticipated considering the strong correlation between visual acuity and reading performance.
CONCLUSION: This proposal is important to occupational therapy practice because the results of this study found associations between functional health literacy level and severity category of visual impairment that hold clinical significance. In general, visual impairment may be an underrecognized barrier to functional health literacy and the self-management of chronic health conditions. Health care providers should avoid use of health literacy assessments with time constraints for older adults with AMD. Timed tests may create unforeseen barriers to reading performance in this population. Additional research is needed to develop population-specific tools and assessments for people with central vision loss caused by AMD.
References
Beverly, C. A., Bath, P. A., & Booth, A. (2004). Health information needs of visually impaired people: A systematic review of the literature. Health & Social Care in the Community, 12(1), 1-24. https://doi.org/10.1111/j.1365-2524.2004.00460.x
Legge, G. E. (2007). Psychophysics of reading in normal and low vision. Erlbaum.
Rudd, R. E. (2007). Health literacy skills of U.S. adults. American Journal of Health Behaviors, 31(1), S8-S18. https://doi.org/10.5993/AJHB.31.s1.3
Warren, M. (2013). Promoting health literacy in older adults with low vision. Topics in Geriatric Rehabilitation, 29(2), 107-115. https://doi.org/10.1097/TGR.0b013e31827e4840
