Accurate Delivery

Study demonstrates visually impaired people get insulin pen dosages right

When it comes to using insulin pens to manage diabetes, the visually impaired do just as well as their sighted counterparts—and in some cases, even better, according to research from the Frances Payne Bolton School of Nursing at Case Western Reserve University.

insulin pen

Labels on insulin pens-used to measure and administer doses of insulin-caution against use by the visually impaired, but the study overturns that thinking.

According to the Centers for Disease Control and Prevention, 23.6 million people in the United States—7.8 percent of the population-have diabetes. Among the 17.6 million diagnosed cases, 3.6 million or about 20 percent, have visual impairment.

As a diabetes educator, Ann S. Williams, the study's lead investigator, knew visually impaired people were successfully using the pen, but needed scientific research to support her observations. During the 2009 National Federation for the Blind meeting in Detroit, Williams recruited 30 individuals who have vision problems that prevent them from reading printed instructions. They were given complete recorded instructions. She also enrolled 30 people from Cleveland who could see and read the pen's directions.

Each participant first read instructions or listened to an audiotape about how to use the insulin pen. Both sets of instructions were essentially the same-the audio instructions were modified slightly to include tactile methods for using the pens. Each participant measured out 10 doses of insulin and injected them into a rubber ball. The ball was weighed immediately before and after the injections for dosage accuracy.

Generally there was little difference between the performance of the two groups, although Williams reports the visually impaired group did slightly better. She speculates that certain individuals in the sighted group performed poorly because they glossed over important instructions on how to use the pen. In contrast, individuals with sight problems listened, step by step, to complete audio instructions before using the pen in the study.

For people with sight problems, measuring and administering insulin presents challenges, since most tools and techniques were designed assuming that people have good vision.

The study shows that people with visual impairment can manage their own insulin accurately when they have access to non-visual tools and techniques and complete instructions in a format they can use, Williams says. "The study also raises questions about the validity of the disclaimer that pharmaceutical companies put on the labels," she says.

The results were published in the Journal of Diabetes Science and Technology. In addition to demonstrating the ability of visually impaired people to use insulin pens accurately, the study also illustrates the importance of including people with disabilities in research studies.

Case Western Reserve has established the Full Inclusion of Persons with Disabilities (FIND) Lab, a National Institutes of Nursing Research/National Institutes of Health-funded center to promote including disabled individuals in mainstream research.

If studies are designed correctly, people with disabilities can participate in research projects that impact their health, Williams says.

The study was funded by the American Association of Diabetes Educators/Sigma Theta Tau International Research grant. Williams's research was also supported during her postdoctoral fellowship through a National Institutes of Health grant.