Home Medical Monitoring Made Difficult?

From the WebMD Archives

March 12, 2001 -- We've all occasionally been stumped by instructions for some technical gadget, like a computer or a VCR. That's frustrating. But what if you're stumped by the instructions for a device you need to monitor your blood glucose because you're a diabetic. Well, that's dangerous, and common, according to a group of Georgia Institute of Technology researchers.

They write in a recent issue of Ergonomics in Design that inherent problems exist with both the instructions to some glucose monitors, and the monitors themselves, and that could be very harmful for someone suffering from the disease because patients must closely track their blood sugar level.

However, medical professionals specializing in treating some of the 16 million diabetics in the U.S. say the machines are so simple that even children can use them.

Regardless, a commonly used blood glucose meter that claimed to be as easy as 1-2-3 in fact required 52 sub-steps before getting to those three easy steps, according to the researchers. "A number of studies in the past have shown that people have trouble using the glucose monitors. We wanted to use human factors as a way to identify the problems and find solutions," Wendy Rogers, PhD, a Georgia Institute of Technology psychologist, tells WebMD.

Indeed, the small machines do play a crucial role in ensuring that diabetics get the proper amount of insulin, which controls blood sugar or glucose levels in their bodies. When glucose levels become too high, there can be irreparable damage to various organs in the body. Diabetes is a leading cause of heart attacks, hypertension, limb amputations, kidney failure, and stroke, and the No. 1 cause of blindness.

Rogers and her team had six people aged 20 to more than 70 try working a commonly used glucose monitor. In observing this practical test of the sugar-level meter, the researchers concluded that the device -- and both its written and video instructions -- was not sufficient to guarantee safe and accurate patient-conducted readings.

Rogers group, by analyzing the instructions with readability standards called the Flesch-Kincaid Grade Level analysis, were able to determine that the user's manual for the monitor was written at an eighth-grade reading level. With this, the scientists say that about 58% of the American population would be able to understand the directions for the monitor, while only half would comprehend the instructions for the test strips (which actually determine the level of blood sugar). According to Rogers, this means that 23 million people 25 years old or older wouldn't understand these directions.


In addition to doing the six-person observational study, the researchers also surveyed 26 diabetics to find out how much trouble they experience using a glucose meter. Forty percent of these participants said they were not comfortable using one until they had used it three or four times. Most of them learned how to use the device on their own, and about a third responded that a medical professional instructed them.

The researchers concluded that based on previous studies, their task for the six people, reported problems from users of the devices, and difficulties they have noticed, people clearly have problems when using these devices, and there are many ways that a mistake could be made. "If they are unable to use meters properly, patients are unable to adjust treatment of their diabetes," they write.

"The instructions for the meters are not done from the users' point of view," Rogers says. "We need to do usability studies on how the instructions are written."

She recommends that developers improve the design of the monitors so that they provide prompts for directing the sequence of steps necessary for taking samples for blood sugar, and presenting both video and written instructions in simple language.

But some diabetes healthcare professionals say that current monitors don't present problems to users, unless they are mentally or physically disabled. Some glucose meters are even designed for the blind; they will talk to you.

"You can take someone who is basically illiterate and show them, and they can do it," says Marilyn Alford, MSN, RN, CS. "Even most 6- and 7-year-olds can use it themselves with their parents' guidance."

The monitors are uncomplicated, just requiring the patient to stick his finger in a hole in the machine and push a button, says Alford, a regional recruiting coordinator for a diabetes type 1 clinical trial at University of Texas Southwestern Medical Center at Dallas.

Mabyn Hager, RN, CDE, a diabetes educator at Baylor Medical Center in Irving, Texas, agrees that monitors currently available are "very easy to use."

"Most have memory with time and date, and they can be downloaded to a computer so the patient can get a printout with pie charts or graphs that they can take to their doctor," Hager says. Many are available in different languages.


One complaint cited by some users in the study was that it takes too long for the monitor to give a result, but Hager says getting a blood drop and running the glucose measurement only takes 30 seconds. A new machine is coming next week that only takes five seconds.

And James Bond-like monitors are hitting the stores, Hager says. One is a watch that measures blood sugar through the skin using an electrical current.

The machines also show -- in sequence -- prompts either by picture or words that ensure that a patient will do the steps in the correct order, Alford says.

Hager and Alford also say that most of the meters are self-calibrating. Rogers and her team had cited this as one stumbling block for many people in using the devices.

Nonetheless, Rogers says the purpose of their study was to illustrate the types of health-endangering problems people encounter with self-use medical devices in general. They want to encourage developers to make changes that will make the gadgets safer.

Above all, Rogers explains, they want people to know that it's not their fault if they have problems with these types of equipment. "We all tend to blame ourselves if something doesn't work right."

WebMD Health News Reviewed by Jacqueline Brooks, MBBCH, MRCPsych
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