New test quickly assesses literacy

Washington -- The idea behind a new assessment tool that can help physicians measure a patient's ability to understand essential health care information began as the nutrition label on a pint-sized carton of vanilla ice cream.

It's the basis for the Newest Vital Sign, or NVS, a health literacy screening tool designed to be administered in three minutes during an office visit.

Available in English and Spanish, it was recently tested on more than 1,000 patients and found to yield accurate assessments, according to a study published in the November/December 2005 Annals of Family Medicine.

"I see and all physicians see, whether they know it or not, patients with limited literacy skills," said Barry D. Weiss, MD, professor of family and community medicine at the University of Arizona College of Medicine, Tucson and the study's lead author.

Nearly half of all American adults -- an estimated 90 million people -- have difficulty understanding and acting upon health information, according to a 2004 Institute of Medicine report. Health literacy, the report concluded, is a neglected pathway to high-quality health care.

The American Medical Association and the AMA Foundation published an educational program in 2003 for physicians about patient health literacy. The program includes both a manual by Dr. Weiss and an instructional video. It advises using plain, nonmedical language, slowing down, and using pictures to enhance both patient understanding and recall.

To determine which patients might benefit from such extra attention, Dr. Weiss and colleagues set out to identify an assessment tool that would meet two criteria.

"One is that it be quick so it wouldn't set back the flow of the office, and another was that it be available in English and Spanish," he said.

The researchers sorted through numerous potential instruments before settling on the ice cream label. "We believe it works best, because it involves a number of different constructs," Dr. Weiss said.

First, numbers are involved: The assessment asks patients: "If you eat the entire container, how many calories will you eat?"

In order to answer correctly -- 1,000 calories -- people need to know how to use numbers effectively, a skill they also must employ to negotiate the health care system, Dr. Weiss noted. "We often underestimate how important it is for patients to be able to use numbers to calculate doses of medications."

Next, the label also requires patients to use abstract reasoning. The NVS asks: "Pretend that you are allergic to the following substances: penicillin, peanuts, latex gloves and bee stings. Is it safe for you to eat this ice cream?" The correct answer is no, because the label indicates that peanut oil is among the ingredients.

And, of course, the label and questions assess reading ability.

Using a nutrition label also makes sense because "if you can't read nutrition labels, you can't eat healthy," Dr. Weiss said.

Just another vital sign

Available free on the Web (link), the test can be used to assess every patient in the practice or just a few.

Dr. Weiss said he encounters many "nonbelievers" during lectures on health literacy. These physicians say they have no problems with health literacy in their practices. But statistics indicate otherwise.

For these skeptics, Dr. Weiss recommends assessing the literacy skills of the first 100 patients who walk through the door. "Most physicians will be quite surprised to find out the percentage of patients they thought were highly educated, literate individuals who turn out not to be."

The best time to use the assessment is when a patient's vital signs are taken. Several hundred patients were recently tested as the nurse took their blood pressures and other measures, and it was determined that the flow of the visit was not impeded.

In validating the NVS, the researchers used an existing instrument, the Test of Functional Health Literacy in Adults, or TOFHLA, as a reference standard. That test takes 18 to 22 minutes to administer in its long version and seven to 10 minutes in its shorter version. Both were deemed by those researchers too lengthy to use during a standard office visit.

Another literacy test, the Rapid Estimate of Adult Literacy in Medicine, or REALM, can be administered quickly, in less than three minutes, but it is not available in Spanish.