Evidence Reviews & Research Summaries

Numeracy describes a person’s ability to understand medical data. We use numeracy to make decisions about screening and treatment options. There are two types of numeracy: subjective and objective. Subjective numeracy is the level of confidence a person has about understanding medical data, while objective numeracy measures a person’s actual math skills. This collection of selected research examines how numeracy affects a person’s ability to understand visual displays of risk, text-only decision aids, and conversations with a health care professional. Overall, findings from these studies suggest numeracy plays a critical role in a person’s ability to make informed decisions about his or her health. People with low numeracy are at increased risk of poorer health outcomes. Public health and health care professionals can improve how they communicate with people who have low numeracy. Learn more by taking these free online courses: Creating Easier to Understand Lists, Charts, and Graphs and Using Numbers and Explaining Risk.

Visual displays of risk

Zikmund-Fisher and colleagues (2011) studied how numeracy influences decisions about treatment for breast cancer recurrence in a sample of 1,781 women ages 40-74. Researchers used pictographs (also called icon arrays) to present treatment choices all at once to one group and in a sequential pattern to a second group. All participants understood risk better when presented with a sequential choice of therapy compared to those who received information about all choices at once. Among women with high numeracy, chemotherapy was selected less often when presented with a sequential pattern and risk of recurrence was low. Women with low numeracy demonstrated greater sensitivity to risk reduction with a sequential pattern compared to seeing all choices at one time.  Study findings suggest presentation of risk data in addition to sequencing choices makes it less likely a person will feel overwhelmed and accept treatment based on misunderstood information.

Hamstra and colleagues (2015) studied how 420 men, median age of 52 years, used graph data to understand recurrence of prostate cancer over time. Participants were randomized to view one of four different graph types (pie, bar, pictograph, or line), with either one number (those affected) or two numbers (those affected and unaffected). Participants who viewed the pictograph with two numbers demonstrated the highest knowledge of cancer recurrence based on reading graph data. Numeracy level was associated with a study participant’s ability to answer questions based on using line graphs or pie charts. Numeracy level was not associated with a participant’s ability to answer questions based on using pictographs or bar charts. Study findings suggest a combination of numbers and graphical display, specifically pictographs, can be used successfully to communicate important information about risk.

Text-only decision aids

Smith and colleagues (2016) studied the association between numeracy, knowledge and attitudes regarding a type of colorectal cancer screening test called fecal occult blood test or FOBt. The sample comprised 964 adults aged 45-59 years. Participants received a mailed booklet about colon cancer screening information. There were no differences in numeracy by age, gender, self-reported health, or marital status. Participants identified as low numeracy were more likely to report less education than those with higher numeracy. Those with low numeracy were more likely to have negative attitudes towards the FOBt and to agree with questions about practical attitudes such as challenges related to keeping stool in the house, privacy, and time. Low numeracy also suggested less likelihood to seek screening or cancer-related information and lower knowledge of colorectal cancer screening. Study findings suggest text-based materials tailored for people with low numeracy can be developed to describe what the numbers mean and explain the perceived and actual risks and benefits of a procedure or treatment.

Lopez-Perez and colleagues (2015) examined the relationship between numeracy and decisions about treatment options for localized prostate cancer in a sample of 279 men over age 50. Researchers provided a written scenario describing prostate cancer and two common treatment options including data on risks and benefits for each. Researchers assessed objective numeracy, a person’s actual ability to solve math problems. Treatment choices were the same between men who had been screened for prostate cancer and those who had not been screened previously. Higher numeracy was associated with selecting active surveillance (AS) over radical prostatectomy (RP). Mortality risk for both options is similar but short term effects vary. RP reduces the potential for cancer growth over time but risks include urinary incontinence and erectile dysfunction. Men who choose AS risk the cancer growing more quickly and making it harder to treat in time, but the short term effect is transitory urinary incontinency. Study findings suggest addressing the information needs of people with low numeracy promotes understanding of long and short term risks and associated quality of life following a treatment decision.

Communication with health care professionals

Ciampa and colleagues (2010) examined the relationship between numeracy and provider communication related to colorectal cancer screening in a sample of adults over age 50. The authors assessed both subjective (confidence in ability) and objective (actual ability) numeracy. Participants with low subjective and objective numeracy were older, non-White, reported less educational attainment and had lower annual income. Respondents with low subjective numeracy were less likely to report their provider ensured understanding, answered their questions, or engaged them in decision making. Respondents with low objective numeracy reported the opposite. Ciampa and colleagues explain this discrepancy by citing different communication needs among those with low subjective and objective numeracy. Low subjective numeracy was also associated with less screening practices. Study findings suggest the importance of assessing perceived confidence and actual ability to understand risk data and tailoring communication accordingly.

Janz and colleagues (2016) surveyed a sample of early-stage breast cancer patients about their doctor’s communication regarding cancer recurrence after surgery. More than half of the study participants (n=3930) reported doctors used words and numbers to communicate risk. Respondents with low numeracy reported less discussion about risk of recurrence. Women who thought they had zero risk of recurrence or overestimated their risk of recurrence were less likely to report having conversations with their doctor about risk. The authors caution that verbal communication alone may lead to using words that are not precise (e.g., unlikely, low risk) and using numbers alone may create a barrier for people with low numeracy. Study findings suggest using both words and numbers to explain risk. Learn how to describe what the numbers mean and explain the perceived and actual risks and benefits.

Numeracy and health outcomes

Petrova and colleagues (2016) studied how numeracy influences a person’s decision to seek medical care when experiencing acute coronary syndrome (ACS). The sample of 102 participants were surveyed five days after experiencing ACS and had a mean age of 58 years. Increased survival rate for ACS is associated with seeking care within 1 hour of symptom onset. In this study, researchers measured objective numeracy using three items asking participants to solve basic math questions. Subjective numeracy was self-reported based on participants’ perceived numerical abilities. Participants with high objective and subjective numeracy reported higher level of education and were more likely to seek care within the first 50 minutes of experiencing cardiac symptoms. Higher objective and subjective numeracy was also associated with having fewer obstructed arteries. A higher objective numeracy level was associated with shorter delays in decision to seek care. Study findings suggest that people with low numeracy are at greater risk of delaying their decision to seek medical care and experiencing negative health outcomes as a result.

Summary

You can support the information needs of people with low numeracy by 1) assessing perceived confidence and actual ability to understand risk data and 2) tailoring communication using a combination of text and visual formats that address perceived and actual risk.

People with heart failure have various self-care activities they must perform, such as monitoring weight, salt and fluid intake, and assessing the effect of diuretics. For patients with limited health literacy, these critical activities can be complicated because they may already have difficulty understanding and using health information to take care of their health. This collection of selected research presents articles that examined the problem of limited health literacy and its influence on the ability of adult patients to manage heart disease. Findings support use of tailored programs to improve patients’ self-care techniques and delay or prevent re-hospitalization. Training staff to deliver tailored education to match people’s health literacy skills may produce health benefits for the patient and cost savings to the health care system.

Training and staff support make a difference in reducing hospital readmission for patients with heart problems

In two separate randomized control trials (Bell et al., 2016, DeWalt et al., 2006) researchers conducted tailored educational sessions, including follow up phone calls, with patients. Sessions included discussion of barriers to medication adherence and a plan to address those barriers. Control group participants in both studies received usual care. Bell and colleagues used pharmacist-provided education while DeWalt and colleagues trained health educators to conduct the intervention. Results from both studies suggest patients in the intervention groups were readmitted less often than those in the usual care groups. Further, DeWalt and colleagues found that compared to the control group participants, those in the intervention group demonstrated an increase in heart failure knowledge and self-efficacy. Additionally, DeWalt and colleagues noted that significantly more participants in the intervention group reported performing daily weight measurement compared to those in the control group up to 12 months after the intervention.

Dennison and colleagues (2011) surveyed 95 hospital patients who received heart failure education provided by the heart failure care coordinator. Prior to hospital admission these patients were living in the community. Researchers cited that overall, participants demonstrated lower than expected heart failure knowledge scores after receiving standardized heart failure education. However, patients with inadequate health literacy demonstrated lower scores on heart failure knowledge compared to patients with marginal or adequate health literacy.  Dennison and colleagues suggest that only providing inpatient education is not enough to increase knowledge of heart failure. Unlike the previous two studies (Bell et al., 2016, DeWalt et al., 2006), researchers in this study did not find an association between health literacy level and readmission rate.

Summary

Findings from these three studies suggest that a tailored approach to heart failure education is helpful for patients of various health literacy levels. The comprehensive approach should include adequate support such as easy to understand education about the patient’s condition or care regimen, and an opportunity for the patient to practice skills, resolve potential issues, ask questions as needed, and receive clinical staff follow up shortly after the sessions.

Health literacy is associated with self-care behaviors related to heart disease

Matsouka and colleagues (2016) surveyed 249 heart failure patients in outpatient settings to assess knowledge of heart failure and related self-care behaviors such as daily weighing, fluid restriction, medication, and contacting health care providers when they experience increased weight gain. Health literacy was assessed in three areas: functional (ability to read and write), comprehensive (ability to access information), and critical (ability to evaluate information). Overall findings suggest that patients with lower health literacy had less knowledge of heart failure and reported performing fewer self-care behaviors, compared to those with higher health literacy.

Other factors associated with lower self-care behavior included age, prior hospitalization for heart failure, chronic kidney disease, and lower heart failure knowledge. An analysis of the different types of health literacy assessed in this study found that critical health literacy, the ability to evaluate information, impacted the practice of self-care behavior more than functional or comprehensive forms of health literacy.

In a large survey study of over 1300 patients with acute heart failure, McNaughton and colleagues (2015) found that patients with low health literacy had an increased risk of death compared to patients with average or above average health literacy. The researchers concluded that a heart disease patient with low health literacy will likely need more assistance from medical staff, particularly during discharge planning and after-care coordination to avoid readmission or death due to poor self-care.

Summary

These findings suggest that health literacy influences how a person manages their care. Limited health literacy can increase the likelihood of poor health outcomes. Given that patients with heart failure need to perform monitoring behaviors and evaluate when to contact a health care provider, the task of assessing barriers to self-care, including limited health literacy, among heart disease patients is critical.

Older adults often experience challenges related to managing multiple chronic conditions, changes in vision and hearing, and some older adults may experience cognitive impairments as they age. This collection of selected research from the last few years presents articles that examined the problem of low health literacy and its influence on an older adult’s ability to manage a health condition or medication regimen. Access ‘Talking with Your Older Patient’ to learn more.

Asthma

Federman and colleagues (2013) assessed measures of asthma control, health resource use, and quality of life among older adults who had been diagnosed with asthma by a doctor. Approximately 158 (35%) of the 452 study participants had low health literacy. In addition, this subgroup was more often older (70 and above), Hispanic, reported low income and educational attainment, had fair or poor health, and a history of intubation. About 9% reported an asthma-associated hospitalization while 23% reported an asthma-associated visit to the emergency department. Findings suggest that older adults who have asthma and low health literacy may be more vulnerable to emergency care and hospitalizations.  Health care providers have the opportunity to assess an older adults’ barriers to asthma self-management techniques including a person’s self-confidence, knowledge about the condition, and health beliefs.

HIV

To design a patient-centered HIV management intervention for African-Americans, Gakumo and colleagues (2015) interviewed 20 patients receiving care at the clinic where the program would be delivered. Participants’ average age was 55 years. Interviewers asked participants about the types of things they wanted to learn about HIV and to describe their preferred learning style. Four themes emerged from the interviews: keep health information simple, use a team-based approach that includes a facilitator living with HIV, tailor to individual needs, and account for level of experience and interest in technology. Findings support the health literacy principle of keeping health messages and instructions simple to avoid overwhelming the person with HIV and risk disengaging them from their care. Use of self-management programs may also help participants become more knowledgeable and involved in their healthcare decision-making. 

Medication information

A 2014 study examined 48 patient information materials on heart disease and type 2 diabetes to identify relevant information for older adults. Researchers found most of the materials were written at a high reading level and the font size on most of the materials was too small for ease of reading. Also, few materials described side effects specific to older adults and when they did it was rarely broken down by age group (over 65, over 80). Health professionals, such as pharmacists, can help older adults review these types of materials to ensure older adults understand how the medication may affect them.

Martin and colleagues (2012) provided 20 participants of an adult day center with a personalized, illustrated medication schedule and six weeks later re-assessed how confident they felt managing their medications. Findings demonstrate a significant increase in self-efficacy and medication adherence after using the illustrated medication cards. Participants also reported the design of the medication cards helped them remember what each medicine was for and what time to take the medicine. Working with older adults, health professionals can reinforce medication adherence using images and plain language principles.

In a 2012 study on medication adherence, researchers divided older adult participants in two groups. The first received usual care, while the second received health topic-specific materials and education from the clinic pharmacist over 9 months. Additionally the pharmacist communicated with clinic doctors and nurses about any relevant medication issues. The authors found that, for patients who had low health literacy, medication adherence was significantly higher among those who received the pharmacist intervention than those who received usual care. This suggests that a tailored approach for patients with low health literacy can improve important health outcomes such as medication safety.

Patients need health care providers who can communicate clearly. Goal 2 of the National Action Plan to Improve Health Literacy outlines strategies all health professionals can use to identify and address health literacy barriers that negatively affect patient care and individual and community health outcomes.

Clinical professionals such as dentists, pharmacists, nurses, and physicians have an especially important role in improving health literacy and implementing strategies from the Action Plan.   This brief summary of research from 2011 to 2014 describes the use of health literacy-based communication strategies by health care professionals.

Dentists and Dental Hygienists

In a 2011 study, two-thirds or more of dentists reported using four communication techniques to ensure effective communication with patients and their understanding of oral health information.  These techniques include handing out printed materials, speaking slowly, using models or radiographs to explain, and using simple language.

These results were from a national survey to determine how frequently dentists use 18 communication techniques. The most commonly used technique was using simple language (90%). Teach-back techniques such as having the patient repeat information and repeat instructions were used by less than 24% of surveyed dentists.
 

A 2013 study of Maryland dentists found similar results. Over 93% of general dentists reported using simple language always or most of the time.  Teach-back techniques were much less used, with only 19% of general dentists asking patients to repeat information or instructions, and 35% asking patients to tell them what they will do at home to follow instructions. Pediatric dentists were more likely to ask patients to tell them what they will do at home to follow instructions (50%).

Results from health literacy environmental scans of community-based dental clinics are reported in a 2014 study.  One component of these scans involved assessing the frequency of dentists’ and dental hygienists’ use of recommended communication techniques. Use of teach-back was low.  Only 7% of providers indicated that they “always” use this technique; 22% indicated they use it “most of the time”; and 33% use it “occasionally”.   Techniques reportedly used “most of the time” or “always” include:

• Limit number of concepts presented at a time to 2-3 (87%)
• Use models or x-rays to explain (87%)
• Use of simple language (99%)
• Use a translator or interpreter when needed (75%)

Nurses

Nurses’ use of communication techniques in encounters with type 2 diabetes patients was assessed in a nine-nurse qualitative 2014 study. Two to four encounters were recorded per nurse. Clarifying health information was the most commonly applied technique (58% often used), followed by repeating health information (33% often used). Checking for understanding was the least applied (81% never used), followed by asking for understanding (42% never used). Medical jargon and mismatched language were often used in 17% and 25% of the encounters, respectively.

Nurse practitioners’ knowledge, experience, and intention to use health literacy strategies were investigated in a 2013 study. The results show that overall knowledge of health literacy and health literacy strategies was low. Screening patients for low health literacy and evaluating patient education materials were found to be areas of knowledge deficit.  However, nurses’ intention to use health literacy strategies in practice was found to be strong.

Pharmacists 

In a 2013 pilot study, older adult patients reported on pharmacists’ use of health literacy-based techniques. The results are by proportion of patients reporting pharmacists’ behavior when the patient filled a new prescription.  

• 89% of spoke to patients about how to take their medication
• 84% spoke to patients about side effects
• 47% discussed the problem for which the medication was prescribed
• 26% communicated a plan for taking medications as prescribed
• 39% explained what may happen if the medication is not taken as prescribed
• 21% asked patients  to explain how they were going to take their medicine
•  0% asked patients  to demonstrate how they were going to use their medicine

Physicians

Results from a 2013 study reveal differences between medical residents’ self-reported communication behaviors and observed behaviors.   Residents reported frequent use of plain language (88%) and teach-back (48%).  However, their actual use of these techniques observed during low health literacy standardized patient encounters was much lower.  Residents used an average of two jargon terms per minute, and only 22% used teach-back.
 

Similar results were found in a 2013 study of medical resident’s communication with newly admitted patients to the emergency room.  Medical students observed internal and family medicine residents while they admitted patients to medical service in the emergency room.  Students used a checklist to assess interactions between residents and patients over an 8 week period.

In 52% of these interactions, residents used medical acronyms when communicating with patients.  Technical medical terms or expressions were used during the history taking in 66% of interactions, and less than 28% of those interactions included at least a partial explanation of terms.  Teach-back was not observed in any of the observed interactions.  Residents for whom English is a second language (ESL) used significantly more technical language than native English speaking residents, while native English speaking residents tended to use more acronyms.

A 2012 study of emergency physicians found the use of simple language and speaking slowly to patients as the only techniques a majority said  they used routinely  (92% and 61%, respectively). When asked about their perceptions of the effectiveness and feasibility of eight different communication techniques (shown below), a majority ranked all but “Reading aloud instructions” as effective, and the physicians said all eight were feasible in the emergency department.  

• Using simple language
• Speaking slowly
• Underlining key points in patient information handouts
• Presenting two concepts at a time and checking for understanding
• Drawing pictures or using models to explain concepts
• Reading aloud instructions
• Asking patients how they will follow instructions at home
• Asking patients to repeat information, teach-back technique

A 2014 study of radiation oncologists explores their understanding and awareness of health literacy among patients, their views regarding health literacy, and identifies techniques they use to communicate to different literacy populations. Participating oncologists report subjectively assessing a person’s literacy level by:

• Monitoring the types of questions asked
• Analyzing the language used
• Examining non-verbal behavior
• Considering a person’s socio-economic situation 

Participants reported the challenges of discussing the benefits and risks of cancer treatment options with lower literacy groups, and tended to provide the basic facts to facilitate understanding. 

Poor quality and variability of medication labeling have been cited as key contributors to medication misuse. Evidence suggests that health literacy plays a significant role in determining how well patients interpret medication labels and take nonprescription and prescription drugs safely and appropriately.  Recent research aimed at improving medication labeling is described below.

Medication Labels

A study published in 2013 finds a patient-centered label was better at preventing participants from exceeding the maximum dose in 24 hours, compared to a standard label. The patient-centered label did not significantly reduce other dosing errors such as taking more than two pills at a time and waiting fewer than four hours between doses.

A study investigating how parents use active ingredient information found many parents, especially those with low health literacy, do not use active ingredient information as part of decision-making related to administering multiple medications.  Overlapping active ingredients across multiple medications put children at risk for overdose.

A 2012 review of 200 top-selling pediatric oral liquid nonprescription medications found that labeling was often variable and in a format that may impair parent understanding of key medication information, including active ingredient information and dosing instructions.  Although most products listed active ingredients on the Drug Facts panel, 18.5% did not list active ingredients on the principal display panel.  Most products included directions in chart form, while few products expressed dosing instructions in pictographic form. 

In a 2011 study, less than 50% of focus group participants reported routinely examining product label information.  Only 31% were aware that acetaminophen is in Tylenol.  Participants achieved consensus on an icon to identify products that contain acetaminophen, a written statement warning of potential liver damage, and indicated a preference for an icon and wording for maximum daily dose.

Medication Instructions

Medication instructions are often the most tangible, frequently used source of information for patients on proper medication use.  However, they are often vague and unnecessarily complex.  Several studies explore how to improve patients’ comprehension of safe and appropriate medication use.

Medication guides were assessed by Wolf et al 2012 to determine their effectiveness in adequately informing patients on safe use.  Current medication guides were found to be of little value to patients, as they are too complex and difficult to understand especially for individuals with limited literacy.  In a follow-up study, the format and layout of three typical medication guides were modified to promote information accessibility.  Comprehension was significantly greater for all three prototypes compared with the current standard, and the guide modified according to health literacy best practices consistently demonstrated the highest scores, and reduced the effects of age and literacy disparities.

Patient preferences for how best to display patient medication information (PMI) were assessed in a study published in 2014. Similar to the Food and Drug Administration’s medication guides, PMI handouts are intended to help all consumers understand key information about their prescription medicine. Participants in one-on-one interviews noted their preference for new PMI handouts over existing medication guides or consumer medication information.  Although many preferences varied by age, education, and health status, most preferred to see drug information in a chunked format that is printed in a sans serif font, such as Arial. 

Patient opinions, preferences and comprehension of standard and improved medication instructions were assessed in a 2013 study.  Patients agreed on the need for simpler terminology and specificity in instructions.  Discussions addressed optimal ways of presenting numerical information, and indication and duration of use information to promote comprehension and safe use. 

In a study published in 2012, limited English proficient (LEP) patients receiving prescription medication instructions in their native language demonstrated significantly greater prescription understanding in comparison to those receiving standard instructions.  In most cases, instruction type was the sole, independent predictor of greater prescription understanding and demonstrated ability to correctly dose multiple prescriptions in multivariate models controlling for relevant covariates. 

Results from a study published in 2011 show the benefit of including pictographic dosing diagrams as part of written medication instructions for infant acetaminophen.  Parents receiving text-plus-pictogram instructions had higher dosing accuracy than parents receiving standard text-only instructions.  These differences were observed among parents with low health literacy, but not for parents with adequate health literacy.

Medication Regimens

Greater regimen complexity may lead to poorer adherence, which in turn will lead to worse health outcomes.  How patients manage their medication regimens, and the role health literacy plays, are explored in the studies described below.

Lenahan et al 2013 investigated drug regimen familiarity among a cohort of patients with hypertension. Specifically, the authors determined the prevalence of patients’ knowledge of their prescribed drug names and dosages compared to those who relied only on physical characteristics such as pill size, shape and color.  Patients dependent on the visual identification of their medicine reported worse adherence, lower rates of blood pressure control and greater risk of hospitalization.

A study published in 2013 explores the relationship between functional health literacy, medication-taking self-efficacy, and adherence to HIV/AIDS antiretroviral therapy.  Functional health literacy was not significantly related to either medication adherence or self-efficacy beliefs.  The authors suggest their measurement strategy as a possible explanation for this unexpected finding. 

Wolf et al 2011 investigate how well patients manage complex medication regimens that require them to consolidate dosing schedules throughout the day.  The finding that many patients, especially those with limited literacy, do not consolidate regimens efficiently supports the Institute of Medicine’s proposal of a universal medication schedule to standardize prescription practices to improve medication adherence.

Research summary: Health literacy, patient activation and health outcomes

A growing body of evidence shows individuals with the skills and confidence to become actively engaged in their health care have better health outcomes.  Ongoing research seeks to determine the relative contribution of measures of health literacy and patient activation to improved outcomes.  Some conceptualizations of health literacy include aspects of motivation and self-efficacy. However, other conceptualizations limit health literacy to a more skills-based construct that involves reading, math, speaking and listening abilities needed to make informed health decisions. While an individual’s motivation and confidence to engage in health self-management are often not measured as part of health literacy, they are included in measures of patient activation.

Below is a summary of recent research into these constructs, how they relate to each other, and their potential for improving outcomes such as health information seeking, comprehension and use, patient self-advocacy, mental and physical health, and costs.

Health literacy, patient activation and health information seeking, comprehension and use

A study published in 2014 investigates the relative contribution of patient activation and functional health literacy to the seeking and use of health information among adults in The Netherlands.  While the researchers acknowledge alternative definitions of health literacy, such as broader definitions that include aspects of motivation, skills and self-efficacy, they employ a functional definition limited to the basic reading and numerical tasks required to function in a health environment.  Among a sample from a consumer panel, they find patient activation to be a stronger predictor for seeking and using health information than functional health literacy. 

Two of the three items used to measure functional health literacy were significantly related to patient activation.  Those who were more confident with filling out medical forms had higher patient activation scores. Those who agreed with having problems learning about their medical condition because of difficulty understanding written information had lower patient activation scores.  Patient activation was not significantly related to receiving help from others with reading.

Hibbard, Peters, Dixon and Tusler (2007) assess the contribution of health literacy, numeracy and patient activation to the comprehension of comparative hospital performance reports, as well as quality choices based on that information.  They found numeracy skill to be the strongest predictor of both comprehension and quality choices. Health literacy was also a strong predictor of both.  Patient activation was only moderately predictive of comprehension and quality choices. However, activation was found to contribute more to the outcomes for those with lower numeracy and health literacy skills, compared to those with higher skills.  Thus, higher activation may compensate for lower skills. 

Health literacy, patient activation and mental and physical health

A study published in 2013 examines the association between health literacy and patient activation as they are most commonly measured among a cohort of older adults. They measured health literacy with the Test of Functional Health Literacy in Adults (TOFHLA) and measured patient activation with the Patient Activation Measure (PAM). The relationship between health literacy and patient activation was weak, but significant. The researchers also examine the independent and combined associations of health literacy and patient activation with physical and mental health.  Lower health literacy was associated with worse physical health and depression.  Lower patient activation was associated with worse physical health and depression, as well as anxiety. Patient activation was the stronger predictor of the two measures for all health outcomes.

Health literacy and patient self-advocacy

Martin et al (2011) examine whether reading, numeracy, speaking, and listening skills are associated with patient self-advocacy when faced with a hypothetical barrier to scheduling a medical appointment.  They define patient self-advocacy as the extent to which individuals demonstrate an increased assertiveness or willingness to challenge providers or other medical authority, and to actively participate in decision-making to ensure they receive the treatment they feel best meets their needs.  They found all literacy skills to be significantly associated with advocacy when examined in isolation. However, greater speaking and listening skills remained significantly associated with better patient advocacy when all four skills were examined simultaneously.

Patient activation and health outcomes and costs

A study published in 2015 examines the extent to which a single assessment of patient engagement, the Patient Activation Measure, was associated with health outcomes and costs over time.  The Patient Activation Measure is scored on a scale of 0 to 100 and indicates four levels of activation which reflect a progression from being passive with regard to one’s health to being proactive.  They found an association between higher activation and improved health outcomes, as well as lower costs, two years later.

Hibbard & Greene (2013) review the available evidence of the contribution of patient activation makes to health outcomes, costs, and patient experience.  In addition to finding evidence of higher activation being associated with better health outcomes and care experiences, they also find evidence that patient activation can be increased through intervention.

Health literate organizations and self-management support

Koh, Brach, Harris & Parchman (2013) propose a Health Literate Care Model that would infuse health literacy into all aspects of a health care organization, including planning and operations, self-management support, delivery systems design, shared-decision making support, clinical information systems to track and plan patient care, and helping patients access community resources.  Central to this model is the support of productive interactions at both the individual and organizational levels.  Perhaps most aligned with the concept of patient activation, the self-management support element of the Health Literate Care Model encourages patients to be empowered and prepared to manage their own health and health care. 

Research summary: Nutritional and food literacy, food labels, and portion size estimation

Health literacy is used broadly to refer to how individuals understand, interpret, and apply health information. However, researchers continue to debate and define what it means to be nutritionally literate and food literate. While some researchers use nutritional literacy and food literacy synonymously, others distinguish the two and refer to nutrition literacy as going beyond understanding the origin of food, how it is cultivated and processed and its impact on health, to being able to act on nutritional information.

A growing body of research shows that individuals who accurately estimate portion sizes and interpret and use food labels have higher nutritional literacy and numeracy skills and realize better health outcomes. Using emolabels and strategies to ease comprehension may help children select more nutritious food and have healthy dietary behaviors. 

Below is a summary of recent nutritional and food literacy research, with emphasis on food labels, portion sizes, and dietary behaviors.

Children and food literacy

Privera et al. conducted a study in which children were asked to choose 4 out of 12 food items in a grocery aisle setting with emo-labels added (happy = healthy; sad = not healthy) and again without emo-labels. Children made overall healthier food choices when emo-labels were present, even when they knew about the unhealthy options available. Emo-labels may not only promote healthier food choices for children, but researchers contend that they may also be a good tool to help increase health literacy at an early age and potentially help reduce rates of childhood obesity.

A preschool program in Australia designed to increase children’s food literacy and encourage children to enjoy vegetables shows that food literacy begins at an early age. The curriculum consists of a one or two hour weekly session taught by dieticians, preschool staff and volunteers.  Whiteley & Matwiejczyk found that after the program, over 70% of children asked for and ate more vegetables and parents and preschool staff also reported that children were more knowledgeable about vegetables and had improved food literacy.

Health literacy skills and use of food labels

A 2014 study finds that young adults with poor health literacy are not likely to use food labels to select food products and are more likely to report an unhealthy diet.  People with higher self-efficacy use food labels more often.  When people use the information on food labels regularly, they tend to have better dietary choices and have better health outcomes. Another study also notes a correlation between poor food label comprehension and low literacy and numeracy skills.

A 2012 study examined the health literacy and nutrition behaviors of low income adults. Race and parental status were found to be significant predictors of health literacy among a sample of Supplemental Nutritional Assistance Program (SNAP) eligible adults. Only 37% of participants had adequate health literacy, as assessed by the Newest Vital Sign (NVS), a health literacy measurement tool, and less than half of them reported using nutrition labels when purchasing food.  Questions that required numeracy skills proved to be most challenging for participants.  

A 2015 study used eye-tracking glasses to measure adults’ visual attention to the nutritional information of food products during a food selection task. Front labels used a familiar red, yellow and green sign and there was a sign with explanatory information near the product. Back labels were the usual nutrition label. Nutrition labels located on the front of products were more likely to be viewed by participants than those located on the back, suggesting that consumers may be more willing to read the shortened and simplified labels.

Sinclair & Hammond investigated how well adults could comprehend food labels. They found that although people self-report high levels of understanding, their actual comprehension of food label information is much lower. Comprehension was lowest among most disadvantaged socioeconomic groups. Higher education and income, and White ethnicity positively correlated with correctly answering questions pertaining to percentage of daily nutritional value of food products. 

Portion Size

A 2011 study examined visual representations of food portion sizes on a web interface, noting that digital applications that help people keep track of their food intake are not always apt for people with low literacy or numeracy skills.   Researchers noted that it is difficult for people with low literacy to estimate portion sizes and their food intake.  Participants often preferred hand gestures such as the shape of a fist, or an extended palm to estimate portion size of shapeless foods, and were more accurate about estimating liquids and shapeless food items, rather than solids.

A study by Huizinga et al. found that although 91% of study participants reported completing high school, only 65% of them were accurate when asked to serve a single serving of food. Participants who overestimated how much food constitutes a single serving were much more likely to have low literacy and numeracy skills than adults who provided accurate estimates.