Low Health Literacy Associated with Healthcare Utilization and Spending
Study finds patient health literacy inversely associated with healthcare utilization and costs, especially for prescriptions.
For the first time, a study published in the International Journal of Health Policy and Management extrapolated individual data to estimate total national healthcare costs due to low health literacy (LHL) in the United States.
Researchers used data from the Medical Expenditure Panel Survey Household Component (MEPS-HC) from 2005 to 2008 to determine nationally representative individual healthcare utilization and expenditures, stratified by health literacy level (HLL), and applied longitudinal weights to extrapolate national estimates.
In 2010 dollars, the study estimated that LHL was associated with approximately $215.1 billion in increased healthcare spending annually. Eighty percent of that increase was attributable to prescription costs, followed by office visits (18.4%) and emergency room visits (1.6%).
This finding was consistent with associations previously found at an individual or aggregate level. At the aggregate level, Vernon et al in 2007 assessed data from the 2003 National Assessment of Adult Literacy (NAAL), which included a health literacy measure, to find that 36% of respondents had LHL that could be attributed to half of their healthcare costs, or $237 billion.
Defining Health Literacy
Health literacy is defined as “the degree to which an individual can obtain, communicate, process, and understand basic health information and services to make proper health decisions.” It has been estimated that only 1 of 10 adults in the United States is health literate.
This study built upon the 2003 NAAL, using the same 0 to 500-point scale developed by the National Research Council for health literacy score (HLS). Below basic HLS (0-184 points) indicates “the ability only to perform tasks such as circling the date on an appointment slip.”
Basic HLS (185-225 points) indicates “the ability, for example, to give 2 reasons why it is necessary for a person to be tested for a specific disease, using evidence from a clearly written pamphlet.”
Intermediate HLS (226-309 points) demonstrates an ability to “perform moderately demanding health literacy activities, such as, establishing what time a person can take a prescribed medication from the prescribed drug label directions.”
Proficient HLS (310-500 points) indicates an ability to “perform more complex and challenging literacy activities, for example, calculating their share of employer health costs from a table.”
One limitation of this approach is that it only considers reading comprehension of printed materials, so it is unable to assess patients’ speaking or listening abilities.
This retrospective analysis assessed data for 22,599 eligible adults from consolidated full year and prescribed medicine event files of MEPS-HC, representing a weighted national estimate of 503,374,648 individuals. The cohort had an average age of 49 years (SD +/- 17.8) and was 83% Caucasian and 57% female. Thirty-seven percent were from the US South.
Researchers used a validated, predictive model to define HLL using patient demographic and socioeconomic factors from US census data. The model was described by Martin et al in 2009 and based on health literacy scores from the 2003 NAAL.
Multivariate regression assessed the relationship between the HLL and (1) physician visits; (2) nonphysician visits (physician assistants, advance practice nurses, and chiropractors); (3) ER visits; (4) office-based visit expenditures; (5) ER expenditures; and (6) prescription expenditures.
The proportion of the study cohort with LHL, defined as basic or below basic HLS, was 22.4%. Prescription spending was the most substantial difference associated with LHL. Increased prescription costs associated with LHL in the United States were estimated at $92 billion annually.
The study also found that patients with LHL utilized the most health care visits across all categories. Annual predicted numbers of physician visits, nonphysician visits, and ER visits for patients with LHL were 6.6, 4.8, and 0.2, respectively, compared with 4.4, 2.6, and 0.1, respectively, for patients with intermediate or proficient health literacy.
Predicted spending per patient per year (PPPY) for office and ER visits was $1284 and $151 respectively for LHL, compared with $719 and $100 PPPY for above basic health literacy (P < .05).
Health literacy seems to be inversely associated with utilization of healthcare visits and spending on visits and prescription medications, translating into substantial financial impact in the United States.
Additionally, the Department of Health and Human Services, the Joint Commission on Accreditation of Healthcare Organizations, and the American Medical Association “have prioritized health literacy as a key patient safety and quality of care issue.”
Strategies to promote health literacy, using tools such as the Health Literacy Universal Precautions Toolkit, should be considered to help improve outcomes and reduce unnecessary costs.