Ability to read medication labels improved by participation in a low vision rehabilitation program.

Demographic projections indicate that the population of the Western world is aging, and evidence suggests an increase in the incidence of conditions, such as age-related macular degeneration (AMD), that produce visual impairments and result in low vision (Maberley et al., 2006). It is expected that in the United States and Canada, the annual number of new cases of visual impairment will double that of the current rate by 2025 (Massof, 2002). In light of these expected demographic changes and the expected increase in the demand for services, it is critical to assess low vision rehabilitation outcomes for interventions on various tasks that are commonly performed in activities of daily living. Data in this regard have been incomplete and sketchy.

Low vision rehabilitation interventions include prescription and training in the use of low vision devices, such as magnifiers, telescopes, selective transmission lenses, electronic devices, and computers; training in skills, such as reading, writing, driving, orientation and mobility, and other activities of daily living; and counseling and social support (Markowitz, 2006). In addition, one can analyze the impact of low vision rehabilitation interventions on selected tasks that are widely performed by people with low vision. Reading labels on prescription medicine bottles is an everyday task that virtually all persons attempt to perform accurately. There have been no reports in the literature on the impact of low vision rehabilitation interventions on this specific task. Thus, the purpose of this study was to assess the impact of low vision rehabilitation interventions on the ability of individuals with low vision to read standard labels on medication packages.

METHODS

The study was designed as a prospective nonrandomized interventional case series. Patients were recruited from the clinical offices of some of the authors who provide low vision rehabilitation services. All the patients who were considered for the study received routine complete low vision assessments and were prescribed low vision interventions. Criteria for inclusion in the study were a confirmed diagnosis of low vision that is not amenable to any further medical or surgical treatments and no history of a neurological disease or cognitive impairment. Only patients who were prescribed and received low vision rehabilitation interventions were included in the study.

Data were collected on the patients' demographic characteristics, diagnosis of low vision, ocular and medical histories, and details on the low vision rehabilitation interventions that were prescribed and implemented. The study protocol included assessments of the patients' distance best-corrected visual acuities using ETDRS charts (Ferris, Kassoff, Bresnick, & Bailey, 1982). A low vision rehabilitation intervention was counted as such if a device (magnifiers of any kind, reading glasses of any power, and any kind of electronic magnification) was prescribed and was used by the patient for self-help with the study task. Nonvisual techniques for identifying medication were not included in the study. The outcome measure was the ability to read unfamiliar standard labels on prescription medication bottles.

Assessments of the use of prescribed medications and of sample medication bottles with standard labels that the patients had not previously used were performed during the initial low vision rehabilitation evaluation and before any devices were prescribed. Sample medication bottles with standard labels were used during testing when the patients' own medication bottles were not available. The patients were asked about the medications they take, the frequency and number of medications that they need to take, and the devices they use to identify the medications, if any. They were allowed to use their own reading devices, if any, for the initial evaluation.

Additional sessions before discharge from the study were dedicated to dispensing devices and providing vision rehabilitation training. Usually during the second session, the device used for the task was introduced (or reintroduced) to the patient, and the patient was instructed in its assembly, maintenance, and appropriate recommended usage. One or more sessions with an occupational therapist were devoted to training in reading skills with suprathreshold optotypes (larger than critical print size) or continuous print materials. Specifically, the participants were taught the proper reading distance that matched the focal distance of the magnification device under the adequate illumination for this task and the appropriate strategy for viewing curved surfaces in some instances. If a device was prescribed as part of the low vision rehabilitation intervention, it was prescribed at the time of the final evaluation. Some, many, or all elements just described may have been performed for some individuals during the initial visit with the occupational therapist. Before discharge from the study, a second assessment was conducted of the participant's ability to identify his or her own prescribed medications or standard labeling on sample medication bottles that the participant had not used previously.

An occupational therapist evaluated the partipants' reading ability at the initial evaluation and at the time of discharge from the study. The participants were asked to grade the degree of difficulty they encountered while identifying their own prescribed medications or standard labels on sample medication bottles that they had not used previously on a scale of 0 to 2, with 0 = unable to access, 1 = able to access partially but not with confidence, and 2 = able to read the printed directions accurately and reliably. These self-assessed responses after a testing trial were taken at face value and recorded, following validation by the observing occupational therapist. The occupational therapist interpreted the 1 rating as indicating some ability to self-administer prescribed medications, regardless of the frequency or accuracy in performing the task, and the 2 rating as reading the same medication labels after multiple trials, reading some or most details on the labels, and reading only some of the listed details printed on the labels.

The study was performed in adherence with the guidelines of the Declaration of Helsinki. The study protocol complied with the guidelines approved by the Research Ethics Committee of the University Health Network of Toronto. Informed consent was obtained from all the participants. Descriptive statistics were used to analyze the data.

RESULTS

Over a span of about 12 months, 57 participants (61% of whom were women and 31% of whom were men) aged 49-95 (median age 80) were recruited for the study presented here. Most participants (78%) had AMD, 9% had glaucoma, and 13% had other conditions. The median distance best-corrected visual acuity for the entire group was 20/105 (range 20/64-20/420). The average number of medications used per participant was 4 with a range of 1-14.

At the time of the initial evaluation, most of the participants (58%) were unable to access the information on the labels of their own prescribed medications (rating of 0), 40% were partially able to access the information but not with confidence (rating of 1), and 2% were able to access the information accurately. At the time of discharge from the study, 94% of the participants were able to read the printed directions on the labels of their prescribed medications accurately and reliably (rating of 2), 2% were unable to read the directions (rating of 0), and 4% were partially able to read the labels (rating of 1). To read the labels, 42 participants (74%) required new optical devices for vision enhancement at an average cost to them of $87.53, and 2 required CCTVs at a cost of $1,800 each. The participants received an average of three occupational therapy training sessions.

DISCUSSION

Visual impairment causes difficulties with everyday living, hampering activities that were previously taken for granted, such as dressing, eating, writing, traveling from place to place, and communicating with others. There is also a staggering economic cost to society associated with visual impairment. In this respect, the annual toll of major adult eye disorders, low vision, and blindness on the U.S. economy alone is estimated at $51.4 billion (Prevent Blindness America, 2007). Outcome measures that are aimed at reducing visual impairment and the economic cost associated with it are the focus of all who are involved in low vision rehabilitation. It is apparent, though, that research on low vision rehabilitation has concentrated on the evaluation of assessment tools for various visual functions and paid less attention to measures of functional vision outcomes from low vision rehabilitation interventions (Teichman & Markowitz, 2008).

Our study is a modest contribution to the effort to remedy this situation. It dealt with a most important aspect of medical care, the visual skills required to self-administer prescribed medications (Haynes, 1979; MacLaughlin et al., 2005; World Health Organization, 2003). Although the impact of visual impairment on this important aspect of medical care is obvious, to the best of our knowledge, it has not been scrutinized before. Low vision rehabilitation aims to teach persons with low vision to perform tasks that they have indicated are important to them, and one of the most common tasks that these persons have identified in clinical practice is reading labels on medicine bottles. Our study demonstrated the extent of the problem, in that at any given time, most patients with low vision cannot identify their own medications. Only a minority can do so either with devices that they they previously acquired randomly over the counter or that were prescribed by a low vision practitioner or by adopting nonvisual strategies.

In our study, 26% of the participants owned reading devices at the time of their initial assessments, and 16% used various nonvisual strategies for performing the same task, but they performed the task of reading labels on their prescribed medication bottles without confidence or accuracy. The prescription of the appropriate device and the right amount of magnification required by each participant produced a major improvement in 94% of the participants to the point where they were able to read the labels accurately and reliably.

The primary source of information available to persons at the time they consume medications is the label on the prescription medicine bottles. Under the best circumstances, the skills to self-administer prescribed medications accurately are problematic. Poor adherence to medication has been associated with a worsening of disease, death, and increased health care costs (Osterberg & Blaschke, 2005). For obvious reasons, poor vision can contribute to this problem. Among the participants with low vision in our study, a significant improvement in the ability to read medication labels was observed with a modest investment in time and resources. This finding appears to demonstrate an important benefit of a relatively simple, inexpensive low vision rehabilitation intervention for this specific task.

Those who are unable to read labels visually can use nonvisual techniques, but these techniques were not evaluated in this study. This was one of the limitations of our study and is an aspect that should be considered in any future studies, since it will support further the cost effectiveness of such low vision rehabilitation interventions. Another limitation of our study was that service was provided by occupational therapists. In many other office settings, the same services are provided by certified low vision therapists and certified vision rehabilitation therapists, which may introduce a variation in the results of outcome measures; hence, all settings need to be included in future studies on this subject. In this respect, our study can serve as a basis for future research that may further clarify the issues raised in this article, as well as emerging ones.

References

Ferris, F. L., Kassoff, A., Bresnick, G. H., & Bailey, I. L. (1982). New visual acuity charts for clinical research. American Journal of Ophthalmology, 94, 91-96.

Haynes, R. B. (1979). Determinants of compliance: The disease and the mechanisms of treatment. In R. B. Haynes, D. W. Taylor, & D. L. Sackett (Eds.), Compliance in health care (pp. 49-62). Baltimore, MD: Johns Hopkins University Press.

Maberley, D. A. L., Hollands, H., Chuo, J., Tam, G., Konkal, J., Roesch, M., Veselinovic, A., Witzigmann, M., & Bassett, K. (2006). The prevalence of low vision and blindness in Canada. Eye, 20, 341-346.

MacLaughlin, E., Raehl, C., Treadway, A., Sterling, T., Zoller, D., & Bond, C. (2005). Assessing medication adherence in the elderly. Drugs & Aging, 22, 231-255.

Markowitz, S. N. (2006). Principles of modern low vision rehabilitation. Canadian Journal of Ophthalmology, 41, 289-312.

Massof, R. W. (2002). A model of the prevalence and incidence of low vision and blindness among adults in the U.S. Optometry and Vision Sciences, 79, 31-38.

Osterberg L., & Blaschke T. (2005), Adherence to medication. New England Journal of Medicine, 353, 487-497.

Prevent Blindness America. (2007). The economic impact of vision problems: The toll of major adult eye disorders, visual impairment, and blindness on the U.S. economy. Chicago: Author. Retrieved from http://www.preventblindness.org/ research/costofblindness.html

Teichman, J., & Markowitz, S. N. (2008). Canadian research contributions to low vision rehabilitation. Canadian Journal of Ophthalmology, 43, 414-418.

World Health Organization. (2003). Failure to take prescribed medicine for chronic diseases is a massive, world-wide problem. Geneva: Author. Retrieved from http://www. who.int/mediacentre/news/releases/2003/pr54/ en/index.html

Samuel N. Markowitz, M.D., F.R.C.S, associate professor of ophthalmology, Faculty of Medicine, University of Toronto, and director, Low Vision Rehabilitation Program, Department of Ophthalmology, University of Toronto, Toronto Western Hospital, University Health Network, Toronto, Ontario; mailing address: 1225 Davenport Road, Toronto, Ontario M6H 2H1, Canada; e-mail: <[e-mail]>. Christine K. Kent, M.A., O.T.R./L., occupational therapist, Department of Ophthalmology, Smith-Kettlewell Eye Research Institute and California Pacific Medical Center, San Francisco, CA; mailing address: 2340 Clay Street, Suite 514, San Francisco, CA 94115; e-mail: <[e-mail]>. Ronald A. Schuchard, Ph.D., director, Rehabilitation Research and Development Center, Atlanta VA Medical Center, 1670 Clairmont Road, Decatur, GA 30033; e-mail: <ronald.schuchard@med. va.gov>. Donald C. Fletcher, M.D., Department of Ophthalmology, Smith-Kettlewell Eye Research Institute and California Pacific Medical Center, San Francisco, CA; mailing address: 2340 Clay Street, Suite 514, San Francisco, CA 94115; e-mail: <floridafletch @msn.com>.