Health Literacy Impact on National Healthcare Utilization and Expenditure

Background: Health literacy presents an enormous challenge in the delivery of effective healthcare and quality outcomes. We evaluated the impact of low health literacy (LHL) on healthcare utilization and healthcare expenditure. Methods: Database analysis used Medical Expenditure Panel Survey (MEPS) from 2005-2008 which provides nationally representative estimates of healthcare utilization and expenditure. Health literacy scores (HLSs) were calculated based on a validated, predictive model and were scored according to the National Assessment of Adult Literacy (NAAL). HLS ranged from 0-500. Health literacy level (HLL) and categorized in 2 groups: Below basic or basic (HLS <226) and above basic (HLS ≥226). Healthcare utilization expressed as a physician, nonphysician, or emergency room (ER) visits and healthcare spending. Expenditures were adjusted to 2010 rates using the Consumer Price Index (CPI). A Pvalue of 0.05 or less was the criterion for statistical significance in all analyses. Multivariate regression models assessed the impact of the predicted HLLs on outpatient healthcare utilization and expenditures. All analyses were performed with SAS and STATA®11.0 statistical software. Results: The study evaluated 22 599 samples representing 503 374 648 weighted individuals nationally from 2005-2008. The cohort had an average age of 49 years and included more females (57%). Caucasian were the predominant racial ethnic group (83%) and 37% of the cohort were from the South region of the United States of America. The proportion of the cohort with basic or below basic health literacy was 22.4%. Annual predicted values of physician visits, nonphysician visits, and ER visits were 6.6, 4.8, and 0.2, respectively, for basic or below basic compared to 4.4, 2.6, and 0.1 for above basic. Predicted values of office and ER visits expenditures were $1284 and $151, respectively, for basic or below basic and $719 and $100 for above basic (P < .05). The extrapolated national estimates show that the annual costs for prescription alone for adults with LHL possibly associated with basic and below basic health literacy could potentially reach about $172 billion. Conclusion: Health literacy is inversely associated with healthcare utilization and expenditure. Individuals with below basic or basic HLL have greater healthcare utilization and expenditures spending more on prescriptions compared to individuals with above basic HLL. Public health strategies promoting appropriate education among individuals with LHL may help to improve health outcomes and reduce unnecessary healthcare visits and costs.


Implications for policy makers
Health literacy presents an enormous challenge in the delivery of effective healthcare and quality outcomes. • We found that individuals with below basic or basic compared to above basic health literacy incurred more healthcare visits, have greater total healthcare expenditures. • Adults with basic or below basic health literacy incurred greater costs for prescription ($3362) than adults with above basic health literacy level (HLL) ($910) (P < .05). Public health strategies promoting appropriate education among consumers with low health literacy (LHL) may help to improve health outcomes and reduce unnecessary healthcare visits and costs. • Health literacy driven health communication strategies may encourage appropriate use of healthcare resources and optimal use of medications.

Implications for public
Health literacy is defined as "the degree to which an individual has the capacity to obtain, communicate, process, and understand basic health information and services to make appropriate health decisions. " Health literacy presents a huge challenge in the delivery of effective healthcare and quality outcomes. We found that consumers with low health literacy (LHL) have greater total healthcare visits, expenditures, spending more on prescription medications. The annual cost of LHL for prescriptions alone was ~$92 billion in the United States. Based on this evidence, we suggest health literacy driven health communication strategies may help patients improve their health outcomes, and reduce unnecessary healthcare visits and costs.

Background
Health literacy is an important aspect of patient care. 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. " [1][2][3][4] Only one in 10 adults in the United States are health literate. 5 Results from the 2003 National Assessment of Adult Literacy (NAAL) 6 shows that 12% of US adults were proficient in health literacy level (HLL), 53% and 22% reported having had intermediate and basic health literacy, and 14% had below basic health literacy. 3,6 Multiple national organizations and institutions, including the Department of Health and Human Services (HHS), 3 the Joint Commission on the Accreditation of Healthcare Organizations (JCAHO), 7 and the American Medical Association (AMA) 8 have prioritized health literacy as a key patient safety and quality of care issue. New federal policy initiatives, including Affordable Care Act (ACA) of 2010, HHS's National Action Plan to Improve Health Literacy, and the Plain Writing Act of 2010 have brought health literacy to a tipping point. 3 Several studies have reported that HLLs may impact healthcare outcomes including mortality, decreased health status in elderly individuals, as reflected by increased hospitalizations, decreased use of preventative services (mammography and influenza vaccination), increased difficulties taking medications, and interpreting medication labels and health information. 4,9,10 In 2011, US healthcare expenditures reached $2.7 trillion dollars ($8680/person). 11 The relationship between health literacy, healthcare utilization and associated expenditures is of particular importance for the US economy. Studies 12-16 on this issue have typically used validated scales to directly measure health literacy for individuals rather than assess community-level indicators of health literacy. Examples of direct methods include the Rapid Estimate of Adults' Literacy, the Test of Functional Health Literacy in Adults, and the Newest Vital Sign. [17][18][19][20] Using these direct methods on small samples of individuals may limit generalizability to larger scales (eg, state or national level). Information obtained with these methods cannot be used with available census data such as the Medical Expenditure Panel Survey (MEPS). 21 In contrast, in 2003, the National Center for Education Statistics (NCES) included a health literacy measure within the NAAL, 6 leading to the first large-scale national assessment of health literacy. Vernon et al 22 used this data to approximate the effect of low health literacy (LHL) on healthcare expenditures based on the percentage of individuals reported in the NAAL survey with below basic or basic HLLs (36%). 6 They found that one-half of the healthcare costs for individuals with LHL were due to literacy effects resulting in an additional $237 billion in healthcare costs. 22 Although these results are informative, individual data from the MEPS Household Component (MEPS-HC) was not available at that time, therefore, only aggregate data were used to estimate healthcare costs. 22 This aggregation approach limits the application of their findings, and as a result, maintain a gap in the literature regarding the impact of health literacy on health utilization and expenditures, especially where methods of assessing individual health literacy via census data such as that found in the MEPS-HC are concerned. Therefore, we conducted the current study using MEPS data to examine the impact of health literacy on current national health utilization and expenditure. Specifically, we explored the association between healthcare utilization (office visits-physician or nonphysician, ER visits), prescription expenditures and HLLs. In addition, we extrapolated national data to estimate the national healthcare costs due to LHL within the United States.  23,24 The MEPS-HC PME files provide detailed information on household-reported prescribed medicines. Each record on this event file represents a unique PMEs. 21 Detailed information on these variables can be found at MEPS website. 21 The study used this event file to calculate the total prescription expenditure for the period 2005-2008, grouped by household respondent. 23,24 Data from MEPS-HC PME files were merged with MEPS-HC consolidated full year files using the respondent unique identifier and the panel number to obtain the final analytical dataset. The longitudinal weights given in the MEPS-HC consolidated full year files were used to derive national estimates. We defined the study inclusion criteria as follows: The estimation of annual expenditures was calculated by averaging the expenditures and visits over the three calendar years data was collected. In a post hoc analysis, the differences in annual adjusted expenditures were estimated for the study population and extrapolated nationally using 2010 US census data (N = 308 745 538). 29 To account for inflation and to match the 2010 census year, expenditures were adjusted to 2010 rates using the Consumer Price Index. 26 A P value of 0.05 or less was considered for statistical significance. All analyses were performed with SAS and STATA ® 11.0 statistical software.  Figure 1) compared to adults with above basic HLL. For all visit types, those with below basic health literacy incurred the most visits (Figure 1). The unadjusted analyses (Table 2) show a significant impact of health literacy on office and ER visits. Compared to individuals with above basic health literacy, those with below basic or basic health literacy averaged more physician (+2.9), nonphysician (+2.8), and ER (+0.2) visits annually. The adjusted analyses (Table 2) confirmed the trend that individuals with below basic or basic health literacy had more total physician or nonphysician visits, incurred more visits than individuals with above basic health literacy. For instance, after adjusting for other variables (individuals insurance types and regions) (  (Figure 2). The unadjusted analyses (Table 2) show a significant impact of health literacy on expenditures for office and ER visits, and prescriptions. Those with below basic or basic health literacy experienced higher expenses for office visits (+$556), ER visits (+$52.2), and prescriptions (+$2939) ( Table 2). The adjusted analyses (Table  2) confirmed the trend that individuals with below basic or basic health literacy incurred more visit and prescription medications expenditures than individuals with above basic health literacy. For instance, after adjusting for other variables (individuals insurance types and regions) ( Table 2), below basic or basic health literacy individuals averaged $1284 office, $151 ER visits, and $3362 prescriptions expenditures annually, compared with $719 office, $100 ER visits, and $910 in those with above basic health literacy (P < .05 for both comparisons). Prescription expenditures were significantly greater in the below basic group ($3362) compared to the above basic group ($910) (P < .05; Table 2). Figure 3 depicted the annual costs for ER visits ($1.9 billion), total office visits ($21.2 billion) and prescription medications ($92.2 billion) attributed to LHL. These extrapolated national estimates showed that the annual costs possibly associated with LHL were $215.1 billion (Figure 3). This increased healthcare cost associated with LHL was not equally divided between the three expenses. In fact, 80% of the overall increased costs were from prescription medications followed by office visits (18.4%) and ER (1.6%) visits.

Discussion
Previous studies [12][13][14][15][16] examining associations between healthcare utilization, expenditures and health literacy were limited to individual-level interpretations given their measurement approaches. [12][13][14][15][16] To address this shortcoming, we conducted the current study, which is multilevel (eg,     household and individual) connects healthcare utilization and expenditure data derived from a national, standardized survey of US adults (MEPS-HC) with health literacy. Only 2 recent studies evaluated healthcare utilizations using the MEPS-HS data. 30,31 One of them evaluated the influence of family composition on office visits, ER visits, and prescription medication use in a pediatric population (age ≤18). The investigators noted significant differences in these parameters between households with three or more children versus one child and between households with multiple adults compared with households with one adult. 30 Another study evaluated the association between individual demographic factors and healthcare resources (access to physician care and preventative healthcare services) and compared rates between the United States and Canada. 31 Although some differences between countries were found, authors attributed those to dissimilarities in health insurance structures. 31 The results of the current study suggest that health literacy may also explain some of the variation in healthcare utilization and expenditures they noted between levels of human aggregation (eg, household, country). It will be important for future studies to further describe the relative role of health literacy and to further delineate the extent to which health literacy acts as a determinant of increased healthcare utilization and expenditures.

Unadjusted
Health literacy is possibly associated with office visits, visits expenditures, and spending on prescription medications. These effects persisted even after adjusting for other variables including insurance types. Individuals with below basic or basic HLLs had a significantly greater frequency of physician visits, nonphysician visits, and ER visits. Lower health literacy individuals also had greater prescription expenditures compared to individuals with above basic health literacy. Possible explanations for these increased prescriptions costs for those include greater severity of disease (especially in the 65 and above age group which exerted about a 56% influence on the prescription medication expenditures) and perhaps a greater reliance on prescription therapy in contrast to a greater emphasis on preventative healthcare for those with higher health literacy. A greater emphasis on preventative services and self-management could also explain the relatively lower ER utilization rates in higher health literate individuals. 32 Another possible explanation for increased prescription expenditures could be that prescriptions are purchased, but are not used optimally by those with LHL thus necessitating more medications to be purchased. This phenomenon also has been observed in several prior studies evaluating LHL and prescription medication use (eg, difficulty in interpreting prescription labels, auxiliary labels, and scheduling medications times throughout the day, etc.). 9,33-41 Although pharmacists or healthcare providers can use health literacy assessments to maximize therapy outcomes, interventions by pharmacists to provide literacy-appropriate information and support have met with mixed success. [37][38][39] Of note, the MEPS prescription medication expenditures included pharmacy records which tracked both insurance and out-ofpocket expenses. Insurance type was included in the adjusted analysis; therefore, the increased costs are less likely to be due to differences in private, public, or self-insurance coverage. The reasons for the increased expenditures and use of healthcare resources are likely multifactorial. If the increased number of ER visits in below basic individuals is in part due to chronic care or conditions that may be managed in an office setting, transitioning that care to the office could result in more cost effective care. Additional office visits focusing on management or prevention of health conditions may also result in fewer ER visits for exacerbations or preventable conditions. The lower number of ER visits for above basic individuals may reflect increased use of preventative services and the increased use of electronic media to identify and manage symptoms. There is a plethora of literature attesting to the efficacy of chronic disease self-management as a mechanism for significantly reducing healthcare burden and improving health in general. 42,43 Public health initiatives considering health literacy driven health communication strategies may encourage appropriate use of healthcare resources and optimal use of medications. Recent national initiatives like "Health Literacy Universal Precautions Toolkit" endorsed by AHRQ encourage "taking specific actions that minimize risk for everyone when it is unclear which patients may be affected. " Universal precautions on health literacy are needed because "providers do not always know which patients have limited health literacy. " In addition, census level data, such as the data used within this study, can help identify areas within the community that may benefit from targeted services. Healthcare entities serving these areas could educate their providers and staff in accessing 42 health literacy and providing information to patients at the appropriate literacy level [44][45][46] which may, in turn, help achieve better health outcomes. 3,4 Our analysis indicated that overall visits and expenditures were inversely related to health literacy, there is the possibility that changes in observed expenditures may have resulted from sampling variation. However, increased healthcare costs due to LHL were also been found by Vernon et al. 22 In addition, the NALS database provided evidence that individuals with 'inadequate' functional literacy had increased hospitalization rates, hospitalization days, and physician visits. 32 Several limitations are worth noting. First, predicted health literacy may not reflect the actual level of health literacy that might be detected by directly measuring health literacy. However, it would be very costly and time consuming to directly access health literacy in a large, nationally representative sample. Therefore, the validated model provided in this study presents a unique opportunity to explore the current health literacy situation nationally. Second, the model derived from NAAL data is limited to the ability to read materials to accomplish health related tasks. Since NAAL assessed health literacy using only printed materials, the model fails to capture a broader  conceptualization of health literacy. For example, oral language (speaking) or aural language (listening) skills were not included as predictors in the model as they were not available in MEPS dataset. Third, because of the nature of the MEPS dataset, we could not establish causality and could only address the associations between health literacy and health services expenditures and utilization. Although we are using a validated tool to calculate HLL, however; that may not reflect accurate HLL.

Conclusion
The main finding from this study was that health literacy is associated with healthcare utilization and expenditures. Individuals with below basic or basic compared to above basic health literacy individuals incurred more visits and spent more on visits and prescription medications. Public health communications promoting health literacy driven appropriate strategies, such as adopting Health Literacy Universal Precautions Toolkit, may help to improve health outcomes and reduce unnecessary healthcare costs.

Ethical issues
We utilized AHRQ provided MEPS data. Publicly available de-identified data was used in this study.