Cardiovascular disease risk and secondary prevention of cardiovascular disease among patients with low health literacy
Cardiovascular disease risk and secondary prevention of cardiovascular disease among patients with low health literacy
T. M. van Schaik 0 1 2 3
H. T. Jørstad 0 1 2 3
T. B. Twickler 0 1 2 3
R. J. G. Peters 0 1 2 3
J. P. G. Tijssen 0 1 2 3
M. L. Essink-Bot 0 1 2 3
M. P. Fransen 0 1 2 3
T. M. van Schaik 0 1 2 3
H. T. Jørstad contributed equally to this work. M.L. Essink-Bot is deceased. 0 1 2 3
0 Department of Public Health, Academic Medical Centre, University of Amsterdam , Amsterdam , The Netherlands
1 Department of Cardiology, Academic Medical Centre, University of Amsterdam , Amsterdam , The Netherlands
2 Department of Endocrinology, Diabetology and Metabolic Diseases, AZ Monica Hospital , Deurne/Antwerp , Belgium
3 Department of Endocrinology , Diabetology and Metabolic Diseases , University Hospital , Antwerp , Belgium
Objective To explore the association between health literacy and the risk of cardiovascular disease (CVD), and to assess the differential effects by health literacy level of a nurse-coordinated secondary prevention program (NCPP) in patients with coronary artery disease (CAD). Methods Data were collected in two medical centres participating in the RESPONSE trial (Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists). CVD risk profiles were assessed at baseline and 12-month follow-up using the Systematic Coronary Risk Evaluation (SCORE). Health literacy was assessed by the short Rapid Estimate of Adult Literacy in Medicine (REALM-D) and the Newest Vital Sign (NVS-D); self-reported health literacy was evaluated by the Set of Brief Screening Questions (SBSQ-D). Results Among 201 CAD patients, 18% exhibited reading difficulties, 52% had difficulty understanding and applying written information, and 5% scored low on self-reported health literacy. Patients with low NVS-D scores had a higher CVD risk [mean SCORE 5.2 (SD 4.8) versus 3.3 (SD 4.1), p < 0.01]. Nurse-coordinated care seemed to reduce CVD risk irrespective of health literacy levels without significant differences. Conclusion Inadequate health literacy is prevalent in CAD patients in the Netherlands, and is associated with less favourable CVD risk profiles. Where many other forms of CVD prevention fail, nurse-coordinated care seems to be effective among patients with inadequate health literacy.
Health literacy; Coronary artery disease; Cardiovascular disease risk; Secondary prevention; Nurse coordinated prevention program
Patients with manifest coronary artery disease (CAD) are
at high risk of recurrent coronary events and death.
Secondary prevention, consisting of a healthy lifestyle and
optimal drug therapy, can reduce this risk . However, the
use of such evidence-based secondary prevention is far from
optimal . It is unknown whether specialised secondary
prevention strategies as recommended by the current
guidelines (i. e. multidisciplinary cardiac rehabilitation,
preventive programs for therapy optimisation, adherence and risk
factor management, and nurse and allied health professional
led programs) are effective for all CAD patients, in
particular those with low health literacy . Health literacy refers
to individual skills to obtain, process, and understand basic
health information and services needed to make appropriate
health decisions [3, 4]. Lower health literacy is associated
with less well controlled blood pressure in primary care
patients with hypertension and heart disease  and worse
adherence to cardiovascular preventive drugs .
Interventions tailored to low health literacy appeared effective in
improving medication adherence [7, 8].
It is estimated that almost 27% of the Dutch population
has limited health literacy, but the prevalence of low health
literacy in CAD patients in the Netherlands is unknown .
Studies in the United States reported low levels of health
literacy in 27 to 54% of patients with heart failure [10–12].
Health literacy is associated with lower educational level,
non-Western ethnic background and age [9, 13, 14].
Reading, listening, and calculating skills, important components
of health literacy, are considered to be a mediator in the
association between educational level and cardiovascular
risk [15, 16]. Data on the prevalence and consequences
of low health literacy in CAD patients in Europe are
limited and evidence on the effect cardiovascular preventive
care or interventions in low health literacy CAD patients is
lacking [17–20]. The Dutch RESPONSE trial (Randomised
Evaluation of Secondary Prevention by Outpatient Nurse
SpEcialists) showed that patients randomised to a
nursecoordinated prevention intervention had better control of
risk factors and a predicted relative risk of mortality than
the control group. The outcome was measured by SCORE,
a risk assessment tool based on age, gender, smoking
status, systolic blood pressure, and cholesterol levels [21, 22].
This scheduled, individual, face-to-face guidance could
potentially be effective among patients with inadequate health
literacy, since it enables tailoring of information and support
to their lower ability to apply information on, for example,
lifestyle and medication in their daily life. We therefore
expect that especially patients with low health literacy would
benefit from a nurse-coordinated intervention.
The general aim of this study was to gain insight into
the prevalence of health literacy among patients with
established CAD in the Netherlands, and to investigate the
effectiveness of nurse-coordinated secondary prevention on
CVD risk in patients with low and adequate health
literacy. For this purpose we used SCORE, an assessment tool
for CVD risk that is based on age, gender, smoking status,
systolic blood pressure, and cholesterol levels.
Our research questions were:
1. What is the prevalence of inadequate health literacy among patients with established CAD in the Netherlands?
2. What is the association between inadequate health literacy and cardiovascular risk profiles (as assessed using SCORE)?
3. Is there a difference in effectiveness of nurse-coordinated care in patients with inadequate and adequate health literacy?
Research population and recruitment
We performed a cross-sectional survey embedded in the
RESPONSE trial, a multicentre randomised, clinical trial
in the Netherlands that investigated the effect of a
nursecoordinated prevention program (NCPP) on top of usual
care (controls) [21, 22]. The protocol of the RESPONSE
trial was approved by the institutional committees on
human research in all recruiting hospitals. The current study
was approved as an addendum to the main trial by the
institutional committee on human research of the Academic
Medical Center – University of Amsterdam, Amsterdam,
Referral to the NCPP included up to four visits during
the first six months after inclusion. At each visit, patients
were seen by a trained nurse specialist. The NCPP focused
on  promoting healthy lifestyles,  managing biometric
risk factors and  increasing medication adherence.
Patients aged 18–80 years were eligible for participation
in RESPONSE if they had been hospitalised for an acute
coronary syndrome (ST-segment elevation myocardial
infarction (STEMI), non-ST-segment elevation myocardial
infarction (non-STEMI), or unstable angina). Exclusion
criteria were: visits to the prevention program not feasible;
not available for follow-up; insufficient mastery of Dutch;
surgery, percutaneous coronary intervention or other
interventions expected within 8 weeks after index event; limited
life expectancy; previously enrolled in an NCPP; NYHA
class 3 or 4 congestive heart failure.
Participants for our survey were recruited between
February and June 2010 in two participating centres of the
RESPONSE trial (Academic Medical Centre Amsterdam
and Medical Spectrum Twente Enschede). All RESPONSE
participants received an introductory letter describing the
objective of the current study and data collection on health
literacy, and were subsequently invited for the survey by
During the RESPONSE trial, data were collected at
baseline and at 12-month follow-up by patient files and patient
interviews, as appropriate. Detailed information on data
collection in RESPONSE has been reported by Jørstad et al.
Background characteristics consisted of: gender;
educational level (classified as low, medium or high); ethnic
background (patients’ and his/her parents’ country of birth);
weight; height; cardiovascular history; index event (acute
coronary syndrome) and any revascularisation; smoking
status prior to index event.
Cardiovascular risk was assessed using SCORE, which
estimates the absolute 10 years cardiovascular mortality
risk based on age, gender, total cholesterol, systolic blood
pressure and smoking status . Blood pressure was
measured using a validated automated sphygmomanometer.
Blood samples were analysed by the local laboratories for
the measurements of lipid profiles, including low-density
lipoprotein cholesterol. Patients were instructed to observe
an 8-hour period of fasting prior to blood sampling.
Health literacy was assessed in separate personal
interviews at or after 12 months of follow-up in RESPONSE.
Interviews were performed at the Academic Medical Centre
Amsterdam or by telephone. We used the following
instruments to measure health literacy: The Rapid Estimate of
Adult Literacy in Medicine (REALM) is a word recognition
test consisting of 66 health-related words divided into three
lists of increasing complexity. Examples are cancer (list 1),
hormones (list 2), hypertension (list 3) . Respondents
receive one point if they pronounce a word correctly. This
results in a total score range of 0–66, which is converted
to a US school grade estimate of reading ability. Scores
below 18 indicate that patients might not be able to read
most low literacy materials, scores between 19 and 44
indicate that patients need low literacy materials, scores
between 45 and 60 indicate that patients may have problems in
reading most patient education materials, and scores above
60 indicate that patients are probably able to read most
patient education materials .
The Newest Vital Sign (NVS) includes objective
assessments of numeracy and the ability to understand and apply
written information. It consists of six questions about the
information on a food label (e. g. If you eat the entire
container, how many calories will you eat?), resulting in a total
score range of 0–6. A score between 0 and 1 suggests a
likelihood of ≥50% of limited literacy, 2–3 indicates the
possibility of limited literacy, and 4–6 almost always indicates
adequate literacy .
The Set of Brief Screening Questions (SBSQ) measures
perceived health literacy [26, 27]. It consists of three
statements about the patient’s perceived ability to understand
and apply health information. Responses are scored on a
5point Likert scale from 0 to 4, added up and averaged. The
response of ‘somewhat’ or less provided optimum
sensitivity and specificity and is considered as an optimal screening
threshold in most studies [26, 27]. This means that an
average score of 2 indicates inadequate health literacy, a score
>2 indicates adequate health literacy.
We previously translated these measures into Dutch
(REALM-D-D, NVS-D-D, SBSQ-D-D), assessed the
psychometric properties and evaluated the cross-cultural
applicability of the measures [28–30]. The Cronbach’s alpha
coefficient for the Dutch REALM-D was 0.91. Cronbach’s
alpha was 0.78 for the Dutch NVS-D. Both coefficients
are regarded as sufficient for group comparisons. The
Cronbach’s alpha coefficient for the Dutch SBSQ-D was
0.69, which indicates an acceptable internal consistency.
All three measures were able to significantly (p 0.01)
differentiate between low and high educated patients on
the basis of statistically significant differences in mean
scores. The correlation of REALM-D scores was strongest
with the SBSQ-D scores (r = 0.59, p = 0.00). The
correlation between REALM-D and NVS-D was moderate (r =
0.32, p = 0.00/r = 0.22, p = 0.04). For the REALM-D and
NVS-D, patients received printed forms by regular mail,
in a sealed envelope, labelled with instructions not to open
the envelope until the start of the interview. This was done
to ensure that the patient did not study the health literacy
tests in advance.
Health literacy scores were dichotomised into adequate and
inadequate health literacy per measure, following
predefined cut-off points [26, 27, 29, 30]. For REALM-D a score
<60 indicated inadequate health literacy, for NVS-D this
was <2, and for SBSQ-D this was <3. Patients with
missing biometric values to calculate SCORE at baseline (2%)
or 12-month follow-up (3%) were excluded from our
analyses. Descriptive analyses were used to calculate the
prevalence of inadequate health literacy among CAD patients
in the Netherlands (RQ1). The association between health
literacy and SCORE (RQ2) was analysed by two sample
t-tests. Since educational level, ethnic background, and age
are generally associated with both health literacy as well
as cardiovascular risk [9, 13, 14, 31, 32], we corrected
for these variables in our analyses. We performed
stepwise linear regression analyses to correct for educational
level, ethnic background and age in the association between
REALM-D and score, NVS-D and score, and SBSQ-D and
SCORE. We used the two-sample t-test to assess differences
in the effect of nurse-coordinated care between health
literacy groups (RQ3). We first analysed the mean change in
SCORE between baseline and 12-month follow-up for the
intervention and control group for the total population. We
then performed the same analyses for strata of low and
adequate health literacy; p-values of 0.05 were considered
significant. We used SPSS statistics V.23 for all statistical
Withdrew consent (n=19)
Not willing to participate (n=22)
Not reached (n=46)
Study population (n=201)
Fig. 1 Flowchart showing the response, AMC Academic Medical
Center, MST Medisch Spectrum Twente
Response and patient characteristics
Fig. 1 presents the study flowchart. In total, 269 of 296
patients were eligible to participate (8 patients died and
19 patients withdrew consent before the start of the current
study). Of these 269 patients, 22 patients refused
participation due to lack of time (n = 16), fatigue (n = 4), or
family circumstances (n = 2), and 46 patients could not be
reached. In total, 201 patients were included in our study
(75%). Patient characteristics are shown in Table 1. Mean
age was 56 years, and 80% were male, 84% had a Dutch
ethnic background. At baseline, 52% were diagnosed with
STEMI, 30% had non-STEMI, and 19% were diagnosed
with unstable angina. In total, 17% of all patients had a
history of prior myocardial infarction, while the majority of
patients had no history of cardiovascular disease (73%).
Prevalence of inadequate health literacy
Table 1 Background characteristics study population (n = 201)
n (%) Mean (SD)
NCPP Nurse Coordinated Prevention Programme, SCORE Systematic
COronary Risk Evaluation
4 missing observations calculating SCORE, 3 missing observations in
reported having difficulties in understanding and applying
health information (SBSQ-D).
Table 2 presents the number of patients with low or
adequate health literacy. According to the REALM-D, 34
patients (18%) had inadequate reading skills, while the
NVSD showed that 103 patients (52%) had difficulty
understanding and applying written information. Eleven patients (5%)
Table 2 further presents SCORE at baseline (mean; SD)
stratified by the level of health literacy. SCORE was higher
in patients with inadequate health literacy as compared with
those with adequate health literacy, according to the
NVSD, the REALM-D and the SBSQ-D. Patients with low
Health literacy n (%)
Mean SCORE (SD)
Intervention group (n = 94)
Control group (n = 107)
Mean change in score
between baseline and
Mean change in score
between baseline and
aAdjusted for educational level and ethnic background. 3 missing observations on REALM-D; 2 missing observations on NVS-D; 1 missing
observation on SBS
4 missing observations calculating Systematic Coronary Risk Evaluation (SCORE); 3 missing observations on REALM-D; 2 missing observations
on NVS-D; 1 missing observation on SBS-Q
D scores had a higher CVD risk (mean SCORE 5.2 (SD 4.8)
versus 3.3 (SD 4.1), p < 0.01). This difference remained
significant after correction for educational level and
ethnic background. After correction for educational level,
ethnic background and age, the difference in SCORE was no
longer significant. The difference in SCORE for the
SBSQD was significant when the model was corrected for
educational level and ethnic background (p = 0.04) but not in
the other models. The difference in SCORE for
REALMD was not significant in any regression model.
a greater improvement in SCORE than patients with
adequate health literacy. For example, patients who had low
health literacy according to the REALM-D had a change
in SCORE of –0.96, this change was –0.28 in those that
had adequate health literacy. While patients with adequate
health literacy in the control group improved in SCORE
after 12 months of follow-up, those with inadequate health
literacy did not improve. However the observed differences
between health literacy groups were statistically not
Association between health literacy and effectiveness
Table 3 shows the mean change in SCORE after attending
the NCPP for the intervention and control group (12 months
of follow-up relative to baseline), stratified by health
literacy level. We did not find significant differences in mean
change between the intervention and control group for the
total population (p = 0.22) or between patients with
inadequate and adequate health literacy (p = 0.23). Patients with
inadequate health literacy in the intervention group showed
Our study shows that inadequate health literacy is highly
prevalent in patients with CAD, ranging from 18% who
have inadequate reading skills to 52% who have difficulty
understanding and applying written information. Patients
with low health literacy had significantly worse CVD risk
profiles. However, the NCPP led to similar reductions in
CVD risk both in individuals with inadequate and adequate
health literacy and was thus equally effective for all.
Health literacy scores found in our study are comparable
with health literacy levels in the general population in the
Netherlands, the UK and Ireland [28–30, 33, 34]. A
limited number of studies have investigated the association
between health literacy and CVD risk. These studies were
either performed in a general population (primary prevention)
or assessed independent risk factors instead of integrated
risk profiles. Martin et al. showed that inadequate literacy
skills were associated with higher CVD risk as measured
by the Framingham algorithm in the general population
. This association was only statistically significant in
women. However, this study was performed in a markedly
different population in the US, consisting of young
individuals in their mid-forties without previous CVD.
McNaugton et al. found that low health literacy (REALM-D) was
independently associated with uncontrolled blood pressure
among 423 urban, primary care patients with hypertension
and coronary disease . Aranha et al. found no association
between health literacy and independent CVD risk factors
among 150 elderly patients seeking care at a patient-centred
medical home in the US .
To our knowledge, our study is the first to investigate
the impact of health literacy on the effects of secondary
prevention by nurse coordinated care as prescribed in the
current European guidelines . We observed that patients
with inadequate health literacy in the intervention group
SCORE had improved risk profiles at 12-month follow-up,
while those in the control group showed no improvement.
Although this difference was not significant, it suggests the
specific need for an NCPP among CAD patients with low
health literacy. This is in line with studies in the US which
demonstrated that patients with low health literacy and heart
failure have a stronger preference for patient-centred
information, and that they benefit more from self-management
programs using adjusted educational materials and
scheduled (telephone) follow-up [36, 37].
Several factors need to be taken into account when
interpreting our results. First, we did not find any statistically
significant results regarding the effectiveness of the NCPP.
This is in contrast to the findings in the RESPONSE trial
where good risk factor control was achieved in 35% of
patients in the intervention group compared with 25% in
the control group at 12 months (p = 0.003). This
difference is probably related to the fact that our sample was
much smaller (201 compared with 754) than the sample
in the RESPONSE trial, and that we only recruited in two
medical centres that participated in the RESPONSE trial.
A larger sample is needed to confirm the significance of
the differences in the effectiveness that we found between
health literacy groups.
Second, all patients participating in clinical trials are
able to read and provide written informed consent,
potentially leading to an oversampling of literate patients. To
account for low literacy, we approached patients in
person or by telephone. Lower ability to read the introductory
letter was therefore not necessarily a limitation. However,
patients choosing to participate in randomised clinical trials
are not representative of the general patient population.
Furthermore, data (for example on health literacy) were
lacking on deceased patients and patients who withdrew
consent. Third, the absolute estimates of the SCORE function
are inaccurate in secondary prevention. We were unable to
use the SMART score for secondary prevention , since
C-reactive protein and kidney function were not assessed in
the RESPONSE trial. However, the difference in SCORE
between the two groups provides an estimate of the relative
overall impact of a risk factor intervention.
Inadequate health literacy is highly prevalent in patients
with documented CAD, and is associated with adverse risk
profiles. It seems that an NCPP leads to the improvement of
risk profiles and that this does not differ between patients
with inadequate and adequate health literacy. A larger
sample is needed to confirm the significance of the differences
in the effectiveness that we found between health literacy
Patients with inadequate health literacy are generally less
likely to receive and/or follow preventive treatment.
However, because of their less favourable CVD risk profile, their
need for effective secondary prevention is greater. We found
that an NCPP is equally effective across health literacy
levels. Where many other forms of prevention fail, an NCPP
seems effective among patients with inadequate health
literacy and therefore offers a promising concept of secondary
prevention of CVD.
The protocol for our survey was approved by the
institutional committees on human research of both participating
Acknowledgements We thank the participants, nurses, and research
personnel of the RESPONSE trial.
Funding The current study had no sponsoring. The RESPONSE trial
was sponsored by an unrestricted grant from AstraZeneca, the
Netherlands. The sponsor had no role in the design, data collection, data
analysis, data interpretation and writing of this report.
Conflict of interest T. M. van Schaik, H. T. Jorstad, T. B. Twickler,
R. J. G. Peters, J. P. G. Tijssen, and M. P. Fransen declare that they
have no competing interests.
Open Access This article is distributed under the terms of the
Creative Commons Attribution 4.0 International License ( http://
creativecommons.org/licenses/by/4.0/), which permits unrestricted
use, distribution, and reproduction in any medium, provided you give
appropriate credit to the original author(s) and the source, provide a
link to the Creative Commons license, and indicate if changes were
1. Piepoli MF , Hoes AW , Agewall S , et al. European guidelines on cardiovascular disease prevention in clinical practice . Rev Esp Cardiol (Engl Ed) . 2016 ; 69 : 939 .
2. Kotseva K , De Bacquer D , Jennings C , et al. Time trends in lifestyle, risk factor control, and use of evidence-based medications in patients with coronary heart disease in Europe: results from 3 EUROASPIRE surveys . 1999 - 2013 . Glob Heart. 2016 ; doi: 10. 1016/j.gheart. 2015 .11.003.
3. Berkman ND , Davis TC , McCormack L. Health literacy: what is it ? J Health Commun . 2010 ; 15 : 9 - 19 .
4. Ratzan SC , Parker RM , Selden CR , Zorn MA , Ratzan SC , Parker RM . Introduction in national library of medicine current bibliographies in medicine: health literacy . Bethesda: National Institutes of Health, U.S. Department of Health and Human Services ; 2000 .
5. McNaughton CD , Jacobson TA , Kripalani S. Low literacy is associated with uncontrolled blood pressure in primary care patients with hypertension and heart disease . Patient Educ Couns . 2014 ; 96 : 165 - 70 .
6. Kripalani S , Goggins K , Nwosu S , et al. Medication nonadherence before hospitalization for acute cardiac events . J Health Commun . 2015 ; 20 (Suppl 2): 34 - 42 .
7. Bell SP , Schnipper JL , Goggins K , et al. Effect of pharmacist counseling intervention on health care utilization following hospital discharge: a randomized control trial . J Gen Intern Med . 2016 ; 31 ( 5 ): 470 - 7 .
8. Miller TA . Health literacy and adherence to medical treatment in chronic and acute illness: a meta-analysis . Patient Educ Couns . 2016 ; 99 : 1079 - 86 .
9. Sorensen K , Pelikan JM , Rothlin F , et al. Health literacy in Europe: comparative results of the European health literacy survey (HLSEU) . Eur J Public Health . 2015 ; 25 : 1053 - 8 .
10. DeWalt DA , Malone RM , Bryant ME , et al. A heart failure selfmanagement program for patients of all literacy levels: a randomized, controlled trial [ISRCTN11535170] . BMC Health Serv Res . 2006 ; 6 : 30 .
11. Laramee AS , Morris N , Littenberg B. Relationship of literacy and heart failure in adults with diabetes . BMC Health Serv Res . 2007 ; 7 : 98 .
12. Morrow D , Clark D , Tu W , et al. Correlates of health literacy in patients with chronic heart failure . Gerontologist . 2006 ; 46 : 669 - 76 .
13. van der Heide I , Uiters E , Sorensen K , et al. Health literacy in Europe: the development and validation of health literacy prediction models . Eur J Public Health . 2016 ; 26 : 906 - 11 .
14. van der Heide I , Wang J , Droomers M , et al. The relationship between health, education, and health literacy: results from the Dutch Adult Literacy and Life Skills Survey . J Health Commun . 2013 ; 18 (Suppl 1): 172 - 84 .
15. Loucks EB , Gilman SE , Howe CJ , et al. Education and coronary heart disease risk: potential mechanisms such as literacy, perceived constraints, and depressive symptoms . Health Educ Behav . 2015 ; 42 : 370 - 9 .
16. Martin LT , Schonlau M , Haas A , et al. Literacy skills and calculated 10-year risk of coronary heart disease . J Gen Intern Med . 2011 ; 26 : 45 - 50 .
17. Ibrahim SY , Reid F , Shaw A , et al. Validation of a health literacy screening tool (REALM) in a UK population with coronary heart disease . J Public Health (Oxf) . 2008 ; 30 : 449 - 55 .
18. Rowlands GP , Mehay A , Hampshire S , et al. Characteristics of people with low health literacy on coronary heart disease GP registers in South London: a cross-sectional study . BMJ Open . 2013 ; 3 : e001503 .
19. Ussher M , Ibrahim S , Reid F , Shaw A , Rowlands G . Psychosocial correlates of health literacy among older patients with coronary heart disease . J Health Commun . 2010 ; 15 : 788 - 804 .
20. Loke YK , Hinz I , Wang X , Salter C. Systematic review of consistency between adherence to cardiovascular or diabetes medication and health literacy in older adults . Ann Pharmacother . 2012 ; 46 : 863 - 72 .
21. Jorstad HT , Alings AM , Liem AH , et al. RESPONSE study: Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists: study design, objectives and expected results . Neth Heart J . 2009 ; 17 : 322 - 8 .
22. Jorstad HT , von Birgelen C , Alings AM , et al. Effect of a nursecoordinated prevention programme on cardiovascular risk after an acute coronary syndrome: main results of the RESPONSE randomised trial . Heart . 2013 ; 99 : 1421 - 30 .
23. Conroy RM , Pyorala K , Fitzgerald AP , et al. Estimation of ten-year risk of fatal cardiovascular disease in Europe: the SCORE project . Eur Heart J . 2003 ; 24 : 987 - 1003 .
24. Davis TC , Crouch MA , Long SW , et al. Rapid assessment of literacy levels of adult primary care patients . Fam Med . 1991 ; 23 : 433 - 5 .
25. Weiss BD , Mays MZ , Martz W , et al. Quick assessment of literacy in primary care: the newest vital sign . Ann Fam Med . 2005 ; 3 : 514 - 22 .
26. Chew LD , Bradley KA , Boyko EJ . Brief questions to identify patients with inadequate health literacy . Fam Med . 2004 ; 36 : 58894 .
27. Chew LD , Griffin JM , Partin MR , et al. Validation of screening questions for limited health literacy in a large VA outpatient population . J Gen Intern Med . 2008 ; 23 : 561 - 6 .
28. Fransen MP , Van Schaik TM , Twickler TB , Essink-Bot ML . Applicability of internationally available health literacy measures in the Netherlands . J Health Commun . 2011 ; 16 (Suppl 3): 134 - 49 .
29. Fransen MP , Leenaars KE , Rowlands G , et al. International application of health literacy measures: adaptation and validation of the newest vital sign in the Netherlands . Patient Educ Couns . 2014 ; 97 : 403 - 9 .
30. Pander Maat H , Essink-Bot ML , Leenaars KE , Fransen MP. A short assessment of health literacy (SAHL) in the Netherlands . BMC Public Health . 2014 ; 14 : 990 .
31. Gijsberts CM , Seneviratna A , Bank IE , et al. The ethnicity-specific association of biomarkers with the angiographic severity of coronary artery disease . Neth Heart J . 2016 ; 24 : 188 - 98 .
32. Krenning BJ , Van der Heiden K. Should ethnicity be included in cardiovascular risk stratification? Neth Heart J . 2015 ; 23 : 42 - 3 .
33. Rowlands G , Khazaezadeh N , Oteng-Ntim E , et al. Development and validation of a measure of health literacy in the UK: the newest vital sign . BMC Public Health . 2013 ; 13 : 116 .
34. Sahm LJ , Wolf MS , Curtis LM , McCarthy S. Prevalence of limited health literacy among Irish adults . J Health Commun . 2012 ; 17 (Suppl 3): 100 - 8 .
35. Aranha A , Patel P , Panaich S , Cardozo L. Health literacy and cardiovascular disease risk factors among the elderly: a study from a patient-centered medical home . Am J Manag Care . 2015 ; 21 : 140 - 5 .
36. Morrow DG , Weiner M , Steinley D , Young J , Murray MD . Patients' health literacy and experience with instructions: influence preferences for heart failure medication instructions . J Aging Health . 2007 ; 19 : 575 - 93 .
37. DeWalt DA , Malone RM , Bryant ME , et al. A heart failure selfmanagement program for patients of all literacy levels: a randomized, controlled trial [ISRCTN11535170] . BMC Health Serv Res . 2006 ; 6 : 30 .