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Table of Contents
Year : 2020  |  Volume : 3  |  Issue : 4  |  Page : 241-246

Knowledge and awareness of ischemic heart disease among primary health-care patients in Riyadh hospitals

1 College of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
2 Department of Cardiac Sciences, King Saud University, Riyadh, Saudi Arabia

Date of Submission18-Jan-2020
Date of Decision23-Mar-2020
Date of Acceptance10-Apr-2020
Date of Web Publication02-Oct-2020

Correspondence Address:
Ahmad S Hersi
Department of Cardiac Sciences, College of Medicine, King Saud University, P.O. Box 7805 (92), Riyadh 11472
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JNSM.JNSM_7_20

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Objectives: This study aims to assess the level of knowledge and awareness about ischemic heart disease (IHD), specifically its warning symptoms and risk factors, among primary health-care (PHC) patients in Riyadh hospitals. Methods: We conducted an observational, descriptive, cross-sectional study in PHC clinics across four main public hospitals in Riyadh from October 2014 to April 2015. Convenience sampling was used to select 162 individuals. The level of knowledge was assessed using a new structured, self-administered questionnaire. Results: Level of knowledge regarding IHD in Riyadh hospitals (King Khalid University Hospital, Al-Iman General Hospital, King Salman Hospital, and King Abdulaziz Medical City) was 69%, 29%, 56%, and 58%, respectively. The level of education played a significant role, as participants with bachelor's and advanced degrees exhibited greater knowledge. Dyspnea was the most frequently cited symptom, while smoking and obesity were the most frequently identified risk factors. Interestingly, only 32% of participants recognized family history as a risk factor. Conclusions: This study highlighted the inadequate knowledge about IHD among PHC patients in Riyadh hospitals. The demographic characteristics had a significant effect on the level of knowledge. This study recommends health-care systems in Saudi Arabia to formulate strategies for IHD awareness.

Keywords: Awareness, ischemic heart disease, primary care, Saudi Arabia

How to cite this article:
Alshaikh HM, Aldosari MS, Alnujaim NH, Albraidi HF, Alajlan SH, Alfuraydi AH, Hersi AS. Knowledge and awareness of ischemic heart disease among primary health-care patients in Riyadh hospitals. J Nat Sci Med 2020;3:241-6

How to cite this URL:
Alshaikh HM, Aldosari MS, Alnujaim NH, Albraidi HF, Alajlan SH, Alfuraydi AH, Hersi AS. Knowledge and awareness of ischemic heart disease among primary health-care patients in Riyadh hospitals. J Nat Sci Med [serial online] 2020 [cited 2022 Jan 19];3:241-6. Available from: https://www.jnsmonline.org/text.asp?2020/3/4/241/287703

  Introduction Top

Ischemic heart disease (IHD) and coronary artery disease are global health problems and the major causes of mortality and disability.[1] In particular, it is estimated that more than 17.92 million deaths are caused annually by IHD worldwide.[2] There are many risk factors that contribute to the development of IHD, such as smoking, poor eating habits, diabetes, hypertension, and a sedentary lifestyle.[3],[4] Regionally, in Africa and the Middle East, the prevalence of IHD is high, and the rate of expected deaths has been expected to increase to 171% between 1990 and 2020.[3] In Saudi Arabia, it has been reported that the prevalence of IHD is 5.5% and that IHD occurs mostly in diabetic patients.[5] In terms of economic burden, the average cost associated with IHD is estimated to be $10,710/patient (40,164 SAR) in 2009.[6]

Locally, there are inadequate data to assess patients' awareness about their medical conditions in outpatient clinic settings. However, the few studies that do exist in this area provide some preliminary information regarding the degree of patient awareness in Saudi Arabia. Namely, a prior study conducted in King Khalid University Hospital (KKUH), Riyadh, Saudi Arabia, found that only 20% of the patients were aware of the complications of their diseases, and this awareness was significantly correlated with the level of education.[7] A large scale screening study conducted in the eastern region of Saudi Arabia also found evidence of limited patient awareness regarding cardiovascular disease. Namely, the study showed that only 5372 (2.7%) out of 197,681 participants were aware of having a cardiovascular disease.[8] Assessing the level of knowledge and awareness about IHD risk factors and symptoms is an important area of research, as the mortality rate is increasing annually,[6] and the associated risk factors are common in Saudi Arabian patients.[9],[10],[11] In this study, the aim was to assess the level of knowledge about IHD and correlate it with demographic factors among outpatient clinic patients in Riyadh hospitals. In addition, we sought to identify the factors that most strongly associated with the level of IHD knowledge.

  Methods Top

Study design and study setting

An observational, descriptive cross-sectional study was carried out in primary health-care (PHC) clinics of four main public hospitals in the city of Riyadh from October 2014 to April 2015.

Study population and sampling technique

Of the 45 hospitals across Riyadh, 13 are public hospitals, which were the main concern of the current study, with no selection of any private hospitals. One public hospital was selected conveniently from each of the northern, eastern, western, and southern districts of Riyadh, resulting in the inclusion of a total of four public hospitals in the study. Convenience sampling was also used to select subjects from PHC clinics in the chosen hospitals. Assuming a prevalence rate of 50% with a two-tailed alpha of 0.05 and a sampling error of 8%, we determined that a sample size of 150 was necessary to obtain 80% power. A low response rate was anticipated, and thus, we attempted to sample approximately 300 people to meet the calculated sample size. The eligible individuals comprised hospital patients who were adult (age ≥18 years) men and women who spoke either Arabic or English. The study excluded individuals who were involved in the medical field, such as physicians, nurses, and allied medical scientists, as well as individuals diagnosed with any form of heart disease. Incomplete surveys or those that contained incorrect answers to specific questions (see knowledge assessment section for additional details) were also excluded. Finally, all patients whose native language was neither Arabic nor English were excluded from the study.

Data collection

A new structured, self-administered questionnaire was employed for this study. For any participants who were illiterate, the questionnaire was administered in an interview format to allow for their participation. The questionnaire consisted of three pages with close-ended questions (see attached appendix), which was divided into three sections. The first section contained questions regarding participants' general information and demographic characteristics. In the second section, participants were assessed for their knowledge of IHD risk factors and symptoms. In addition, they were asked to identify the leading cause of death in Saudi Arabia and worldwide. In the third section, participants were given three close-ended questions to determine their attitude regarding IHD. A pilot study was conducted on a separate set of participants (n = 20) to assess the validity of the questionnaire prior to data collection. Of the 292 individuals originally invited to participate in the study, 203 agreed to be involved (response rate 69.5%). However, only 162 questionnaires were completed and eligible for data analysis based on the inclusion criteria discussed above. Permission from the institutional review board of the University was obtained before conducting the study (Approval Number: A13-2014), and written informed consent was also obtained from each individual before participation.

Knowledge assessment

The level of knowledge regarding IHD risk factors was assessed by asking participants to label each risk factor listed on the form with one of three responses: “risk factor,” “not a risk factor,” or “I don't know.” A total of 10 established risk factors were included: Family history of IHD, aging, being overweight, diabetes mellitus, smoking, high blood pressure, high cholesterol level, physical inactivity, excess stress, and drinking alcohol.[12],[13] In addition, one protective factor (“eating healthy food”) and one unassociated factor (“excessive water intake”) were included in the list to identify participants who were carelessly answering the form. Participants who selected both factors simultaneously were excluded from the analyses. The knowledge score was adapted from Vaidya et al.[12] and calculated as follows: 1 point was given for each correctly identified risk factor, and points were neither given nor deducted for incorrect or “I don't know” answers, resulting in a maximum possible score of 10.

The level of knowledge regarding IHD symptoms was assessed by asking participants to identify the possible symptoms of IHD from a list that contained chest pain, unusual fatigue, breathing difficulty (i.e., dyspnea), pain or numbness in the arms, pain in the teeth or jaw, excessive sweating, vomiting, dizziness or light-headiness, and loss of consciousness.[12],[13] In addition, two incorrect symptoms were included: Pain in the abdomen and pain in the leg. For each correctly identified symptom, participants received 3 points for chest pain, 2 points each for breathlessness, sweating, and vomiting, and 1 point each for pain in the arm, teeth, or jaw, fatigue, light-headedness, unconsciousness, and fatigue. In addition, 1 point each was given if pain in the abdomen and pain in the leg were answered “no.” Points were neither given nor deducted for answers of “I don't know.” The maximum score possible was 16.[12]

When combining the above scores regarding IHD risk factors and symptoms, possible scores on total knowledge ranged from 0 to 26 (mean = 15.27, median = 16, standard deviation = 4.8). Participants were categorized into low knowledge (0–15; 48.1% of participants) and high knowledge groups (16–26; 51.9% of participants) based on their scores.

Perception and actual knowledge assessment

Participants' perceived level of knowledge about IHD was measured by asking them to answer the following statement: “How would you estimate your knowledge regarding IHD?” A score of 1 or 2 indicated that the participant was “not informed,” a score of 3 indicated “moderately informed,” and a score of 4 or 5 indicated “well informed.”[13]

Attitudes and preventive measures

Participants were asked close-ended questions regarding what they deemed to be the most appropriate action to deal with a symptomatic patient with IHD, as well as an additional question about taking protective measures against IHD.

Data analysis

SPSS version 21 (IBM Corp., Armonk, N.Y., USA) was used for data entry and analysis. Descriptive statistics were calculated for participants' level of knowledge regarding IHD risk factors and warning symptoms.

  Results Top

Characteristics of primary health-care patients in Riyadh hospitals

The sociodemographic characteristics of the participants are listed in [Table 1]. The majority of the participants (n = 50, 30.9%) were from King Abdulaziz Medical City, and the number of female participants (n = 85, 52.5%) was slightly higher. Additionally, participants were more likely to have a bachelor's or a higher degree compared to other education levels.
Table 1: Sociodemographic characteristics of Riyadh hospital patients

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Awareness of risk factors and warning symptoms

[Table 2] shows participants who were able to correctly identify the risk factors associated with developing IHD when close-ended questions were asked. Participants recognized smoking (n = 141, 87%) and obesity (n = 139, 86%) as risk factors for IHD more frequently than other risk factors. In contrast, having a family history of IHD was the least frequently cited risk factor (n = 52, 32%).
Table 2: Correctly identified risk factors of ischemic heart disease among Riyadh hospital patients

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[Table 3] illustrates participants' awareness of the warning symptoms of IHD. Dyspnea (n = 129, 80%) was the most frequently cited symptom, followed by chest pain (n = 120, 74%). Interestingly, only 20 (12%) participants were able to recognize pain in the teeth or jaw as a symptom of a heart attack. Finally, fewer than half of the participants (46%) identified excessive sweating as a warning symptom.
Table 3: Correctly identified symptoms of ischemic heart disease among Riyadh hospital patients

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Differences in ischemic heart disease knowledge as a function of sociodemographic factors

[Table 4] illustrates the relationship between participants' sociodemographic characteristics and the level of knowledge. It was observed that KKUH patients were more likely to exhibit high knowledge of IHD (68.6%) compared to the patients of other hospitals. On the other hand, Al-Iman General Hospital (IGH) patients were more likely to exhibit the lowest level of knowledge (71.1%; P = 0.002). In addition, the level of knowledge differed as a function of education level, as patients who completed a bachelor's degree or held advanced degrees were more likely to obtain high knowledge scores than participants with lower levels of educational (63.4%; P = 0.019).
Table 4: Level of knowledge regarding ischemic heart disease as a function of sociodemographic characteristics

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Perceptions related to heart disease

When participants were asked about the leading cause of death in Saudi Arabia and worldwide, the most frequent answer was cancer (n = 54, 33%), followed by heart disease (n = 37, 23%), as shown in [Figure 1]. While there were no gender differences in participants' ability to identify heart disease as the leading cause of death, participants who exhibited high knowledge scores were more likely to identify heart disease as the leading cause of death (76%; P < 0.01).
Figure 1: Distribution of the perceived leading cause of death in Saudi Arabia and worldwide

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Comparing actual and perceived knowledge of ischemic heart disease

Knowing a friend or relative with heart disease was not associated with the level of knowledge regarding IHD, as 32 (47%) participants who did not know a friend or relative with heart disease were labeled as having high knowledge (P = 0.504). When comparing actual and perceived knowledge regarding IHD, 4 (40%) participants who perceived that they were well informed exhibited low knowledge, while 55 (45%) of those who perceived they were not informed exhibited high knowledge (P = 0.011).

Attitudes and measures taken for heart disease prevention

Results indicated that 97 (60%) participants believed that IHD could be prevented, with 61 (63%) of those achieving high knowledge scores (P = 0.002). However, of these 97 participants, only 38 (39%) had taken actions to protect themselves from the disease. Moreover, out of all survey participants (n = 162), only 53 (33%) had taken measures to protect themselves against IHD. When comparing across hospitals, King Salman Hospital patients were most likely to take measures to protect themselves against IHD (n = 14, 44%), while IGH patients were least likely to be motivated to take protective measures (n = 11, 24%; P = 0.235). In addition, participants between the ages of 35–44 years were more likely to recognize IHD as a preventable disease (n = 30, 77%; P = 0.058).

In terms of knowledge differences, 30 (36%) participants who scored high and 23 (29%) who scored low had taken protective measures against IHD (P = 0.419). Patients who claimed that they had taken protective measures indicated that they had done so to feel better (n = 28, 52%), to live longer (n = 13, 25%), and to avoid seeking medication (n = 19, 36%). When closed-ended questions regarding what the participant would do if someone was having symptoms of IHD were asked, the most frequently selected answer was to immediately take the patient in question to the hospital (n = 91, 56%), followed by calling an ambulance (n = 54, 33%). Only six (3.7%) participants reported that giving painkillers was an appropriate response.

Health information sources used by participants

The majority of survey participants chose the internet (n = 60, 37%) as their preferred source of information while knowing a friend or family member with IHD was the second most frequent answer (n = 55, 34%). Participants who were 45 years and older cited the doctor as their preferred source of information. In addition, those who were labeled as having high knowledge were more likely to receive their health information from the internet.

  Discussion Top

We believe this study is the first in Saudi Arabia to use a validated questionnaire to assess the knowledge of IHD, in terms of the warning symptoms and risk factors, among PHC clinic patients. Our findings indicate that a relatively large number of participants (48.1%) are classified as having low knowledge regarding IHD, which has significant implications for PHC patients, as most are diagnosed with chronic diseases, such as diabetes mellitus and hypertension, hence they are possibly at risk for IHD.[14],[15] In addition, several aspects of IHD knowledge were largely unrecognized, including a family history of IHD as a risk factor and symptoms of teeth or jaw pain.

The fact that many participants failed to recognize several IHD risk factors is significant, as several unmodifiable risk factors, such as age, gender, and family history, play a role in the development of IHD.[16] Family history, in particular, deserves special attention, as it has been associated with the development of IHD at an earlier age. Indeed, the work by Nielsen et al.[17] demonstrated that individuals whose sibling or mother suffered a myocardial infarction (MI) are at significantly higher risk of experiencing an MI. Moreover, this risk is particularly elevated among individuals whose parents experienced an MI before the age of 50. The lack of knowledge regarding IHD risk factors demonstrated by the current results poses a great public health risk, as many participants were unaware that family history represented an independent risk factor for IHD. Although many participants were unable to recognize several unmodifiable risk factors for IHD, most participants were able to identify age as an influential risk factor. Indeed, almost half of the participants correctly identified age as contributing to IHD, which is even greater than the number of patients who identified diabetes mellitus, a more commonly known risk factor in the Saudi population. Given that age has been identified as the most important unmodifiable risk factor for IHD in the neighboring country of Iran, these findings are significant.[18]

In addition to the relative lack of understanding regarding IHD risk factors, many participants underestimated jaw and teeth pain as a symptom of heart disease, which is consistent with other studies. In particular, the work by Swanoski et al.[19] found that the question “Do you think pain or discomfort in the jaw, neck, or back are symptoms of a heart attack?” was the least correctly identified symptom (54% answered correctly). Indeed, the current study found evidence of a discrepancy between actual and perceived knowledge, as only 60% of participants who described themselves as well informed were actually classified in the high knowledge category. Similarly, 55% of those who reported a knowledge deficit regarding heart disease were classified as having low knowledge. These findings suggest that there is a significant issue regarding the lack of awareness of IHD within the Saudi Arabian community.

The current study also found that socioeconomic status (SES) played a role in the knowledge of heart disease, as individuals high in SES exhibited higher knowledge than individuals low in SES. These findings are consistent with the results of a Canadian national survey by McDonnell et al.,[13] which found that knowledge of heart health was higher among individuals of medium and high SES. Moreover, when comparing knowledge levels across hospitals, we found that individuals in the IGH sample exhibited significantly lower knowledge compared to those in the KKUH sample, despite a similar participant pool being questioned across all four hospitals. In contrast to IGH, KKUH has a great interest in patient education and frequently organizes health campaigns to increase awareness among their patients, which suggests that effective health education programs contribute to a better knowledge of IHD.

The most correctly identified symptom of IHD in the current study was dyspnea, followed by chest pain and loss of consciousness. In contrast, McDonnel et al.[13] reported that chest pain (43%) was the most frequently identified symptom of IHD in a Canadian population, while dyspnea was identified by 38% of the population. Swanoski et al.[19] found that 92.7% of the participants correctly answered the question “Do you think chest pain or discomfort are symptoms of a heart attack?” and 86.5% correctly answered the question “Do you think that shortness of breath is a symptom of a heart attack?” The findings generally seem to be consistent with previous studies, and the participants identifying a less common but an important symptom of IHD is promising.

Although IHD remains one of the leading causes of death in Saudi Arabia,[20] the majority of the participants did not recognize this fact, as they identified cancer as the leading cause of death. Indeed, research has found that there is a striking difference in heart disease awareness between western and Saudi societies, as the majority of individuals are able to identify heart disease as the leading cause of death in the former but not the latter. For example, a study by Mosca et al.[21] has demonstrated that awareness of heart disease in the United States is increasing, as 55% of women were able to correctly identify heart disease/heart attack as the leading cause of death in 2005, compared to only 30% in 1997. Thus, spreading awareness regarding the prevalence and incidence of IHD remains an area of continued concern in Saudi Arabia.


Despite the above findings, the current study has a few limitations. First, although this study expands on the previous literature that has been conducted on IHD across the world, there were only a limited number of local studies to which we were able to compare our results. Second, given that the current study was conducted specifically within the city of Riyadh, participants' level of education and the quality of hospital care may differ from that of other cities, precluding the generalization of our results. Finally, this study relied on convenience sampling and, therefore, not representative of the general population.

  Conclusions Top

This study highlights the fact that there is inadequate knowledge about IHD among outpatient clinic patients in Riyadh hospitals. Demographic factors played a significant role in the level of knowledge, as participants who resided in northern Riyadh (where KKUH is located) exhibited higher knowledge of IHD. Moreover, participants who had a higher level of education were more knowledgeable about the disease as well. Given that awareness of IHD risk factors and symptoms is essential to take preventive measures, this study can be used by health care systems in Saudi Arabia to formulate strategies to develop such awareness, as well as to increase public awareness to associated health campaigns.


We would like to thank Dr. Shafi and Mr. Armen for their guidance during the initial research process.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: A systematic analysis for the Global Burden of Disease Study 2017. Lancet 2018;392:1789-858. Erratum in: Lancet 2019;393:e44.  Back to cited text no. 1
Roth GA, Johnson C, Abajobir A, Abd-Allah F, Abera SF, Abyu G, et al. Global, regional, and national burden of cardiovascular diseases for 10 causes, 1990 to 2015. J Am Coll Cardiol 2017;70:1-25.  Back to cited text no. 2
Almahmeed W, Arnaout MS, Chettaoui R, Ibrahim M, Kurdi MI, Taher MA, et al. Coronary artery disease in Africa and the Middle East. Ther Clin Risk Manag 2012;8:65-72.  Back to cited text no. 3
Musaiger AO. Diet and prevention of coronary heart disease in the Arab Middle East countries. Med Princ Pract 2002;11 Suppl 2:9-16.  Back to cited text no. 4
Al-Nozha MM, Arafah MR, Al-Mazrou YY, Al-Maatouq MA, Khan NB, Khalil MZ, et al. Coronary artery disease in Saudi Arabia. Saudi Med J 2004;25:1165-71.  Back to cited text no. 5
Osman AM, Alsultan MS, Al-Mutairi MA. The burden of ischemic heart disease at a major cardiac center in Central Saudi Arabia. Saudi Med J 2011;32:1279-84  Back to cited text no. 6
Al-Khowaiter SS, Al-Maawi AM, Al-Obaidy MS, Al-Ali AS, Al-Rukban MO, Al-Sedrani YA, et al. Patients awareness of their medical conditions in multi-specialty outpatient clinics in Saudi Arabia. Saudi Med J 2008;29:1797-801.  Back to cited text no. 7
Al-Baghli NA, Al-Ghamdi AJ, Al-Turki KA, El-Zubaier AG, Al-Mostafa BA, Al-Baghli FA, et al. Awareness of cardiovascular disease in eastern Saudi Arabia. J Family Community Med 2010;17:15-21.  Back to cited text no. 8
Al-Nozha MM, Al-Mazrou YY, Arafah MR, Al-Maatouq MA, Khalil MZ, Khan NB, et al. Smoking in Saudi Arabia and its relation to coronary artery disease. J Saudi Heart Assoc 2009;21:169-76.  Back to cited text no. 9
Midhet FM, Sharaf FK. Impact of health education on lifestyles in central Saudi Arabia. Saudi Med J 2011;32:71-6.  Back to cited text no. 10
Kumosani TA, Alama MN, Iyer A. Cardiovascular diseases in Saudi Arabia. Prime Res Med 2011;1:1-6.  Back to cited text no. 11
Vaidya A, Aryal UR, Krettek A. Cardiovascular health knowledge, attitude and practice/behaviour in an urbanising community of Nepal: A population-based cross-sectional study from Jhaukhel-Duwakot Health Demographic Surveillance Site. BMJ Open 2013;3:e002976.  Back to cited text no. 12
McDonnell LA, Pipe AL, Westcott C, Perron S, Younger-Lewis D, Elias N, et al. Perceived vs. actual knowledge and risk of heart disease in women: Findings from a Canadian survey on heart health awareness, attitudes, and lifestyle. Can J Cardiol 2014;30:827-34.  Back to cited text no. 13
Fabian W, Majkowska L, Stefański A, Moleda P. [Prevalence of diabetes, antidiabetic treatment and chronic diabetic complications reported by general practitioners]. Przegl Lek 2005;62:201-5.  Back to cited text no. 14
Tocci G, Nati G, Cricelli C, Parretti D, Lapi F, Ferrucci A, et al. Prevalence and control of hypertension in the general practice in Italy: Updated analysis of a large database. J Hum Hypertens 2017;31:258-62.  Back to cited text no. 15
Osman AK, al-Nozha MM. Risk factors of coronary artery disease in different regions of Saudi Arabia. East Mediterr Health J 2000;6:465-74.  Back to cited text no. 16
Nielsen M, Andersson C, Gerds TA, Andersen PK, Jensen TB, Køber L, et al. Familial clustering of myocardial infarction in first-degree relatives: A nationwide study. Eur Heart J 2013;34:1198-203.  Back to cited text no. 17
Khalili D, Sheikholeslami FH, Bakhtiyari M, Azizi F, Momenan AA, Hadaegh F. The incidence of coronary heart disease and the population attributable fraction of its risk factors in Tehran: A 10-year population-based cohort study. PLoS One 2014;9:e105804.  Back to cited text no. 18
Swanoski MT, Lutfiyya MN, Amaro ML, Akers MF, Huot KL. Knowledge of heart attack and stroke symptomology: A cross-sectional comparison of rural and non-rural US adults. BMC Public Health 2012;12:283.  Back to cited text no. 19
Memish ZA, Jaber S, Mokdad AH, AlMazroa MA, Murray CJ, Al Rabeeah AA, et al. Burden of disease, injuries, and risk factors in the Kingdom of Saudi Arabia, 1990-2010. Prev Chronic Dis 2014;11:E169.  Back to cited text no. 20
Mosca L, Mochari H, Christian A, Berra K, Taubert K, Mills T, et al. National study of women's awareness, preventive action, and barriers to cardiovascular health. Circulation 2006;113:525-34.  Back to cited text no. 21


  [Figure 1]

  [Table 1], [Table 2], [Table 3], [Table 4]


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