Health literacy statistics show how differently people find, understand, evaluate, and use health information. The available evidence spans U.S. assessments from 2003 and 2017, a European survey conducted from 2009–2011, and population studies in Iran, Liberia, and Türkiye. Because the surveys use different scales, questions, and populations, their percentages should be compared cautiously rather than treated as one global measure.
Contents
- U.S. adult health literacy levels
- Differences by age, gender, and insurance
- Understanding health care providers
- Vulnerable groups in eight European countries
- Health literacy among Iranian adults
- Digital and vaccination health literacy in Liberia
- Health-literacy tasks among Syrian refugees
U.S. adult health literacy levels
The 2003 National Assessment of Adult Literacy (NAAL) remains a major U.S. benchmark for describing adult health literacy. Its categories measured how well adults could perform health-related tasks, including reading and using information. The assessment did not place most adults at either extreme: the largest group was at the Intermediate level.
In the 2003 NAAL health-literacy assessment, 14% of U.S. adults were at the Below Basic level, 22% were at the Basic level, 53% were at the Intermediate level, and 12% were at the Proficient level. These four categories describe the distribution reported by the National Center for Education Statistics for the 2003 assessment.
The figures indicate that 36% of adults were in the two lower categories, Below Basic or Basic, while 65% were in the Intermediate or Proficient categories. That grouping is a direct combination of the reported category percentages and helps show the broad shape of the distribution, but it does not replace the NAAL categories or suggest that all adults within a category have identical abilities.
The 2003 results are historical. They should be read as a baseline from that measurement period, not as a current estimate of U.S. health literacy. The NAAL health-literacy findings provide the category results, while the report The Health Literacy of America’s Adults provides additional breakdowns.
Differences by age, gender, and insurance
The 2003 NAAL report also showed variation in average health-literacy scores by age. U.S. adults aged 65 and older had an average score of 214. Adults aged 16–18 had an average score of 244, and adults aged 25–39 had an average score of 256. These are averages for the named age groups in the 2003 assessment; they are not percentages and should not be interpreted as proficiency rates.
Gender differences were narrower than some of the differences associated with insurance coverage. Women scored 6 points higher than men on average in the 2003 NAAL health-literacy assessment. Men also had a Below Basic health-literacy rate 4 percentage points higher than women. Both findings come from the 2003 NAAL materials and describe the survey’s scoring and category results at that time.
Insurance status was associated with a different distribution across the four levels. The table summarizes the percentages reported for adults with employer-provided insurance and for adults with no health insurance in 2003.
| Insurance coverage in 2003 | Below Basic | Basic | Intermediate | Proficient |
|---|---|---|---|---|
| Employer-provided insurance | 7% | 17% | 62% | 14% |
| No health insurance | 28% | 25% | 41% | 7% |
Among adults with employer-provided insurance, 7% were Below Basic, 17% Basic, 62% Intermediate, and 14% Proficient. Among adults with no health insurance, 28% were Below Basic, 25% Basic, 41% Intermediate, and 7% Proficient. These results are from The Health Literacy of America’s Adults, and the association should not be read as proof that insurance status alone caused the difference.
Understanding health care providers
Health literacy also involves communication during care. A 2017 U.S. National Health Interview Survey measure asked adults aged 25 and older who had seen a health care professional whether they easily understood information from their providers most or all of the time.
Overall, 91.6% of these U.S. adults said they easily understood provider information most or all of the time. The result varied by education: 93.9% of adults with at least a bachelor’s degree reported this level of understanding, compared with 85.2% of adults without a high school diploma.
The same 2017 measure showed a smaller difference by sex. The percentage was 91.0% for men aged 25 and older and 92.1% for women aged 25 and older. These statistics describe self-reported ease of understanding among people who had seen a health care professional; they are not the same measure as the NAAL performance-based literacy levels.
The CDC QuickStats report identifies the source as the 2017 National Health Interview Survey. The wording “most or all of the time” matters: the figures do not mean that every respondent always understood every provider explanation.
Vulnerable groups in eight European countries
The European Health Literacy Survey examined health literacy across eight countries during 2009–2011. In this sample, limited health literacy was more common among people reporting several forms of social, financial, educational, or health-related disadvantage.
Across the eight-country sample, 74% of people reporting very low social status had limited health literacy. Limited health literacy was also reported for 73% of people describing their self-perceived health as poor or very poor. Among people at International Standard Classification of Education (ISCED) level 0 or 1, 68% had limited health literacy.
Financial difficulty showed similar patterns. Sixty-seven percent of people who found it very difficult to pay for medication had limited health literacy, while 66% of people who found affording a doctor fairly or very difficult had limited health literacy. In addition, 66% of people severely limited in activities by health problems had limited health literacy.
These figures come from the eight-country survey sample and period, not from all European residents today. The report Health literacy: The solid facts presents the findings in the context of social determinants and health inequalities. “Limited health literacy” is the survey’s reported classification and should not be assumed to have the same definition as Below Basic, Basic, or inadequate literacy in another study.
Health literacy among Iranian adults
A nationwide population-based survey in Iran collected data in 2015 and analyzed 8,439 valid questionnaires. The response rate was 94.3%, calculated from 8,439 valid questionnaires out of 8,950 questionnaires.
The mean health-literacy score was 10.2 on a 0–20 scale. In the same survey, 45.7% of participants had inadequate health literacy. Education differences were substantial in the reported results: more than 95% of illiterate participants had inadequate health literacy, while only 41% of participants with a university degree had adequate health literacy.
The survey also reported results by health-literacy domain. Individual empowerment had the highest inadequate-health-literacy result, at 73.2%. Communication and decision-making skills had an adequate-health-literacy result of 46.3%.
The Iranian results use their own 0–20 score and adequacy categories, so they cannot be converted directly into the U.S. NAAL levels or the European limited-health-literacy measure. The study, Health literacy among Iranian adults: findings from a nationwide population-based survey in 2015, reports the survey’s methods and definitions.
Digital and vaccination health literacy in Liberia
Liberia’s population health-literacy survey measured general, digital, navigational, and vaccination-related topics in 2024. For general health literacy, 45.5% of respondents had inadequate literacy, 26.4% had problematic literacy, 23.8% had sufficient literacy, and 4.4% had excellent literacy.
Digital access and usefulness were more limited than the vaccination attitudes reported in the same survey. Twenty-six percent of respondents had ever searched for health information. Among respondents who considered online searching, 80% said searching online for health information was difficult or very difficult, and 80% said finding the exact information sought was difficult or very difficult. Seventy-seven percent said understanding information found online was difficult or very difficult.
Only 29% said it was easy or very easy to clearly formulate a written message for a health provider. In a typical week, 18% used websites for health-related information, 17% used social media or online forums for that purpose, 18% used a digital device related to health or health care, and 17% used a health app on a mobile phone for health-related information.
Sixty-three percent said digital resources for health-related information were not relevant to them. The result was 59% among urban respondents and 71% among rural respondents. It was 56% among male respondents and 69% among female respondents. The share who had ever searched for health information was 15% among men and 11% among women, and 20% among urban respondents compared with 6% among rural respondents.
Vaccination findings were more positive. Ninety-eight percent agreed that vaccination protects them and their children, and 97% thought vaccines were safe. Fifty-eight percent said information on recommended vaccinations was easy or very easy to find, while 68% said it was easy or very easy to understand why they or their family might need vaccinations. These results are from the Republic of Liberia Population Health Literacy Survey, measured in 2024.
Health-literacy tasks among Syrian refugees
A 2019 WHO survey of Syrian refugees in Türkiye focused on practical health-literacy tasks. Fifty-one point zero percent of respondents said they were never able to read and understand patient-education material. A similar 52.1% said they were never able to read and understand the patient rights and responsibilities sheet.
Medication instructions were also difficult for many respondents: 52.0% said they were never able to understand and differentiate dosage and usage instructions on a medication bottle. The survey separately reported form-completion tasks by sex. Among men, 15.6% could often or always write their name and complete a treatment-consent form, compared with 13.3% of women. For a past medical history form, the corresponding percentages were 13.4% for men and 11.8% for women.
These statistics describe Syrian refugees surveyed in Türkiye in 2019 and specific self-reported tasks. They should not be generalized to all Syrian refugees or interpreted as a current national estimate. The source is the WHO Survey on the health status, services utilization and determinants of health of the Syrian refugee population in Turkey.