Research conducted by RTI and others has shown that about 36 percent of English-speaking adults in the United States have limited health literacy, making it difficult for them to understand and use basic health information.
For example, lower health literacy in older Americans is linked to poorer health status and a higher risk of death. Researchers also have found a link between low health literacy and a lower likelihood of getting flu shots and of understanding medical labels and instructions, and a greater likelihood of taking medicines incorrectly.
By examining health literacy, researchers can identify where people struggle to comprehend health-related information and use that knowledge to improve interventions to help people lead healthier lives.
Expanding What We Know about Health Literacy
Many instruments used to study health literacy look primarily or only at reading ability. To address the gaps left by these instruments, RTI designed the Health Literacy Skills Instrument (HLSI)—with funding from the National Cancer Institute—to assess four separate domains of health literacy.
In addition to reading ability, HLSI assesses skills needed to understand text and locate and interpret information in documents, and to use quantitative information (numeracy). HLSI also assesses an individual’s ability to listen effectively (oral literacy) and to seek information through the Internet (navigation). Thus, the HSLI measures health literacy at a more holistic and practical level to ensure that patients understand all aspects of health care—from navigating a hospital, to listening to a phone recording and understanding what number to push, to understanding medications.
Available for public use, HLSI is an objective tool for intervention research studies, practice-based assessment, and surveillance. Researchers and practitioners can use HLSI for a variety of purposes, including evaluating interventions or examining the relationship between health literacy and health outcomes. To reduce data collection costs and minimize potential discomfort or embarrassment among participants, HLSI can be self-administered using a computer.
To develop HLSI, we assembled a team of experts in health communication, health services research, psychometrics, literacy, health literacy, plain language, cultural competency, and clinical medicine. Our team conducted a series of cognitive interviews to refine the original 38-item questionnaire, then pilot tested and eventually trimmed the instrument down to 25 items. We also developed a shorter 10-item version of HLSI.
HLSI Aligns with Patient Engagement
The results of our testing suggest that using a skills-based approach such as HLSI is an effective means for measuring health literacy. Our findings indicate that HLSI reflected a range of tasks and skills that adults are likely to face in their daily lives as they face health care-related decisions.
Other studies have shown that individuals are increasingly expected to take a more active role in their health care. More people are taking proactive steps, such as seeking preventive health services, eating better, and getting more exercise. They also are recognizing signs of illness and disease, self-managing chronic illnesses, and getting more involved in their health insurance coverage.
This evolution in the role of individuals in their health care both increases the need for health literacy and changes the definition and context of what constitutes health literacy. HLSI can help researchers determine where there are gaps between the increasing demands of health communication and the health literacy of the American public.