https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article Heart Failure Patients’ Knowledge and Barriers of Low Sodium Diet Adherence in Erbil City ABSTRACT INTRODUCTION Heart failure, often referred to as congestive heart failure (CHF), is the inabil- ity of the heart to pump sufficient blood to meet the needs of the tissues by providing oxygen and essential nutrients. However, the term CHF is misleading, because it indicates that patients must experience pulmonary or peripheral congestion [1]. Heart failure, an exceedingly common cardiac condition, is associated with high rates of morbidity and mortality including frequent hospital admissions [2]. Sodium restriction has remained a core therapy for managing sodium and fluid retention in patients with acute and chronic heart fail- ure [3]. Heart failure is a chronic illness that afflicts more than 5,000,000 Ameri- cans and contributes to more than 286,700 Background and objective: A low sodium diet is a cornerstone of non-pharmacologic therapy for heart failure patients. The objective of the study was to assess knowledge and perceived barriers of low sodium diet adherence of heart failure patients in Erbil City. Methods: A descriptive, cross sectional study design was conducted among a sample of 50 patients diagnosed heart failure in Medical Wards and Cardiac Care Units at both Rizgary and Hawler Teaching Hospitals in Erbil City from Feb 2018 to Oct 2019. Patients who met the inclusion criteria were selected for participation of the study, interviews based on a questionnaire patient’s sociodemographic, clinical characteristics and the Dietary Sodium Restriction Questionnaire (DSRQ). Frequency, percentage, and the chi- square test were used for analyzing data. Results: The results show that majority of heart failure patients were low knowledge (80%) and high perceived barriers (66%) to low sodium diet adherence. There were significant associations between knowledge and barrier with age group (p-value=0.01; p- value=0.04), gender, (p-value=0.00; p=0.05), level of education (p-value=0.00; p- value=0.02) and economic status (p-value= < 0.001; p-value= <0.001). Conclusion: Results of the study show that heart failure patients had low knowledge and perceived more barriers to adherence of low sodium diet. Key words: Heart Failure; Knowledge; Perceived barriers; Low sodium diet Chnar Salahaddin Qadir; Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq. )Correspondence: chnar.qadir@hmu.edu.krd) 47 Erbil Journal of Nursing & Midwifery Received: 6/11/2019 Accepted: 22/12/2019 Published: 30/5/2020 https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article deaths annually. The prevalence of heart failure increases by approximately 550,000 patients [4]. A low-sodium diet is an ac- cepted treatment of patients with heart failure, although minimal evidence exists on the appropriate amount of sodium in- take for this population. Certain heart fail- ure guidelines have liberalized dietary sodi- um recommendations, which actually ex- ceed guidelines for healthy adults [5]. Alt- hough the low-sodium diet is a fundamen- tal non-pharmacologic component of heart failure care, most people with heart failure have considerable difficulty in following such a diet [6]. Fluid overload, usually sec- ondary to dietary sodium indiscretion, was identified as a major reason for heart fail- ure exacerbations that resulted in hospital- ization and high prevalence of non- adherence to the low-sodium diet [7]. Moreover, restricting sodium intake, the role of dietary sodium in heart failure man- agement has been fully established in high- ly effective medical therapy. Recent data highlighted an alternative hypothesis that sodium restriction may be harmful in heart failure patients and low-sodium diet in combination with high-dose diuretics and fluid restriction promoted increases in hos- pital readmission and death [8]. The pur- pose of this study is to determine the knowledge of a low-sodium diet in the care of patients with heart failure and substan- tial barriers to adherence that patients face. There are no prior studies done for assessment of patients’ knowledge and barriers toward adherence of low-sodium diet in Erbil City. A descriptive cross sectional study design was used to assess heart failure patients’ knowledge and perceived barriers to low- sodium diet adherence in medical wards and cardiac care units at both Rizgary and Hawler Teaching Hospitals from February 2018 to October 2019 in Erbil City. In order to obtain accurate data and a representa- tive sample, a non-probability (purposive) sample was used to select heart failure pa- tients according to the following criteria: patients who agree to participate in the study, patients with a medical diagnosis of heart failure, age more than 18 years old and have been taking treatment for at least the past one month. Sample size esti- mation was calculated by following statisti- cal formula: sample size =Z² pq/d² {z=confident interval 95% or 1.96, p= prev- alence 0.02.9, q= (1-p) =0.971, d= sampling error 0.05}[9]. Sample size = Z²pq/d² = (1.96) ² * (0.029) * (0.971) / (0.05) ² =43, for representative sample of 50 heart fail- ure patients chosen in this study. Data were collected through a standardized questionnaire comprising of sociodemo- graphic and clinical characteristics includ- ing age, gender, level of education, marital status, occupation, residential area, eco- nomical status, cigarette smoking, hospi- talization in last year, and comorbidity in addition to the New York Heart Association Class (NYHA), a clinical tool used to evalu- ate cardiac symptoms on a patient’s daily activities. Class I patients do not have any limitations of physical activity. Class II pa- tients have slight limitations of physical activity, but ordinary physical activity re- sults shortness of breath, or chest pain. Class III patients have limitations of limited physical activity and Class IV patients are unable to carry out any physical activity without discomfort [10]. The Dietary Sodi- um Restriction Questionnaire (DSRQ), an instrument based on the theory of planned behavior which was cross-culturally adapted [7] and validated for use in Brazili- an Portuguese, with the name (Questionário de Restrição de Sódio na Di- eta) was used in part two. The DSRQ demonstrated to be a reliable tool for measuring adherence to dietary sodium 48 Erbil Journal of Nursing & Midwifery METHODS https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article More than three quarters (78%) of the heart failure patients were hospitalized in the last year and higher proportion of the patients had hypertension (72%), coronary heart disease (64%) and diabetes (56%). restriction in patient’s heart failure and comprises of two subscales: knowledge (6 items) and perceived barriers (8 items). Patients responded to each item by recording one of three options (agree =2, neutral=1, disagree =0) [7,11]. Regard- ing level of knowledge, if total score is equal to or less than 6, the patient is con- sidered to have low knowledge, while scor- ing more than 6 is considered high knowledge. Low perceived barriers were indicated if total score is equal to or less than 8, whereas scoring more than 8 indi- cated high perceived barriers. Data was analyzed using Statistical Package for the Social Sciences (SPSS) version 22, descrip- tive and inferential statistics were used to finding outcome of the study such as fre- quency, percentage, mean and standard deviation and statistical tests such as chi- square, p-value of equal or less than 0.05 was considered a statistically significant. Table 1 shows the sociodemographic and clinical characteristics of 50 patients with heart failure (HF) who participated in the study. Regarding age range from 30-69 years, 36% of patients ranged their age group between 50-59 with a mean age of 58.07±12.39, more than half percentage (58%) of them were males and 42% were females; 54% were illiterates while 6% of them graduated from university and major- ity of the participants (78%) were married. Moreover, 36% were unemployed, more than three quarters (88%) of patients resid- ed in urban areas, 46% of them reported insufficient economic status and 72% of them were non-smokers. Severity of heart failure as measured by New York Heart As- sociation (NYHA) showed that most of pa- tients had symptomatic and functionally compromised set in their classes of II and III (32%, 42% respectively). 49 Erbil Journal of Nursing & Midwifery RESULTS Table 1: Socio-demographical of heart failure patients Variables n=50 N (%) Age group (years) 30-39 17 (34) 40-49 5 (10) 50-59 18 (36) 60-69 10 (20) Gender Male 29 (58) Female 21 (42) Level of education Illiterate 27 (54) Primary school 11 (22) Secondary school 9 (18) University graduated 3 (6) Marital sta- tus Married 39 (78) Widowed 7 (14) Divorce 4 (8) Occupation High profession 2 (4) Unskilled worker 15 (30) Housewife 15 (30) Unemployed 18 (36) Residential area Rural 6 (12) Urban 44 (88) Economic sta- tus Insufficient 23 (46) Sufficient 17(34) Exceed need 10(20) Cigarette Yes 14 (28) smoking No 36(72) New york heart associa- tion Class I 9 (18) Class II 16 (32) Class III 21 (42) Class IV 4 (8) Hospitalized Yes 39 (78) in last year No 11(22) Comorbidity Hypertension 36 (72) Coronary heart disease 32 (64) Diabetes mellitus 28 (56) https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article whereas, lowest percentage (28%) of per- ceived barrier in item “following a low-salt diet is hard to do because rarely cooked”.Table3 reveals overall patient’s knowledge and perceived barriers of fol- lowing a low-sodium diet adherence among heart failure patients. The majority (80%) of patients had low knowledge and perceived high barriers (66%) to following a low - sodium diet adherence 50 Erbil Journal of Nursing & Midwifery Table 2 illustrates items of knowledge and perceived barriers of adherence to a low sodium diet. Heart failure patients had highest percentage (42%) of knowledge in item “eating a low-salt diet will keep swell- ing down”, while they had lowest percent- age (20%) knowledge in item “understand how to follow a low-salt diet”. Also, heart failure patients reported perceived main barrier (62%) in item “family members are not following a low - salt diet” Table 2 :Patient Knowledge and Perceived barriers about following a low-sodium diet Knowledge and Perceived Barriers (n=50) Disagree Neutral Agree N (%) N (%) N (%) Items of knowledge 1-Understand how to follow a low-salt diet. 23 (46) 17 (34) 10 (20) 2- Keep track of the total amount of salt eating in a day. 17 (34) 22 (44) 11 (22) 3- Pick out which foods on the grocery are low in salt. 18 (36) 21 (42) 11 (22) 4- Eating a low-salt diet will keep fluid from building up in body 24 (48) 14 (28) 12 (24) 5- Eating a low-salt diet will keep swelling down. 14 (28) 15 (30) 21 (42) 6- Eating a low-salt diet will breathe easier 18 (36) 17 (34) 15 (30) Items of barriers 1- Food does not taste good on a low-salt diet 7 (14) 20 (40) 23 (46) 2-There are enough types of low-salt foods to satisfy my appetite 1 (2) 21 (42) 28 (56) 3-Following a low-salt diet is hard to do because rarely cooked 12 (24) 24 (48) 14 (28) 4-Following a low-salt diet takes too much time. 12 (24) 21 (42) 17 (34) 5-Following a low-salt diet takes too much money. 10 (20) 21 (42) 19 (38) 6-Following a low-salt diet is hard to understand. 18 (36) 16 (32) 16 (32) 7-The families members are not follow a low-salt diet. 10 (20) 9 (18) 31 (62) 8-Following a low-salt diet is hard to do when I go out to eat. 16 (32) 8 (16) 26 (52) https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article 51 Erbil Journal of Nursing & Midwifery Table 4 and 5 illustrates the association between demographic data with knowledge and perceived barriers of low low-sodium diet adherence. The results show that there is a significant association between age group and knowledge (p-value=0.01) and perceived barrier (p-value=0.04). Also, gender is significantly associated with knowledge (p-value= <0.001) and perceived barrier (p-value=0.05). Concerning educational level, there is a significant association between level of education with knowledge (p-value= <0.001) and perceived barrier (p- value=0.02). There is a significant associa- tion between economic status and knowledge (p-value= <0.001) and barrier (p-value= <0.001). In regard to smoking, there is a significant association found with knowledge (p-value= <0.001), while not significant in barrier (p-value =0.06). Table 3: Overall patient knowledge and perceived barriers about low-sodium diet Overall of knowledge and perceived barriers (n=50) N (%) -Knowledge Low Knowledge (0-6 score). 40 (80) High Knowledge (7-12 score). 10 (20) -Barriers Perceived low Barriers ( 0-8 score) 17 (34) Perceived high Barriers ( 9-16 score ) 33 (66) Table 4:Association between demographic data and Knowledge of low low-sodium diet adherence Variables (n=50) Knowledge Low High N (%) N (%) df P-value Chi- square Age group (years) 30-39 15 (30) 2(4) 3 0.01 9.94 40-49 3(6) 2(4) 50-59 17(34) 1(2) 60-69 5(10) 5(10) Gender Male 28(56) 1(2) 1 <0.001 11.82 Female 12(24) 9(18) Educational level Illiterate 24(48) 3(6) 3 <0.001 17.42 Primary school 4(8) 7(14) Secondary school 9(18) 0(.0) University graduate 3(6) 0(0) Economic sta- tus Insufficient 13(26) 10(20) 2 <0.001 14.67 Sufficient 17(34) 0(0) Exceed need 10(20) 0(0) Smoking status Yes 36(72) 0(0) 1 <0.001 32.14 No 4(8) 10(20) df=degree of freedom, P-value less than 0.05 consider significant https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article 52 Erbil Journal of Nursing & Midwifery Heart failure is an eminent problem, and patient awareness of the disease and sub- sequent adherence to the treatment may decrease the burden of this serious prob- lem. In this study, the minority of heart failure patients (20%) reported that they understand how to follow a low-salt diet. This result is comparable with the observa- tion study that shows that 40% of the pa- tients were following a low sodium diet [12]. While this result is contrast with study reported the majority of patients reported that they received a recommen- dation to follow a low-sodium diet and that they understood how to follow the diet. One explanation for this result may be that patients recalled only limited infor- mation about how to follow a low-sodium diet despite reporting that they know how to follow the diet. When asked about what they were told regarding how to follow the diet, most patients recalled that they were simply told to watch the amount of salt they ate or to avoid adding salt to foods. It is not possible in this study to deter- mine whether the limited information recalled was due to reduced memory, poor concentration or inadequate teach- ing by health care providers or patients’ illiteracy. The present study displayed that major barriers faced by heart failure patients was within the item “the family members are not following low-salt di- et”. It is supported by previous research which demonstrated that having an in- volved spouse increases dietary adher- ence. Unfortunately, the most common barriers reported by patients were relat- ed to friends and family. Majority of family members did not eat the same diet and most friends and relatives did not serve appropriate foods when pa- tients visited. It is not possible to deter- mine whether this was due to lack of awareness or lack of consideration. Re- gardless, working with patients to help them determine the best strategies Table 5:Association between demographic data and Perceived barriers of low low-sodium diet adherence Variables (n=50) Barriers Low High N (%) N (%) df P-value Age group (years) 30-39 9(18) 8(16) 3 0.04 7.95 40-49 2(4) 3(6) 50-59 6(12) 12(24) 60-69 0(0) 10(20) Gender Male 13(26) 16(32) 1 0.05 3.60 Female 4(8) 17(34) Educational level Illiterate 13(26) 14(28) 3 0.02 9.69 Primary school 2(4) 9(18) Secondary school 0(0) 9(18) University graduate 2(4) 1(2) Economic status Insufficient 2(4) 21(42) 2 <0.001 13.86 Sufficient 11(22) 6(12) Exceed need 4(8) 6(12) Smoking status Yes 15(30) 21(42) 1 0.06 3.36 No 2(4) 12(24) DISCUSSION df=degree of freedom, P. value less than 0.05 consider significant https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article 53 Erbil Journal of Nursing & Midwifery to inform friends and families of their die- tary needs may help. Close friends and family members should be included in all teaching about following a low-sodium diet. Alternatively, clinicians, whenever possible should speak directly with friends and family members to increase their awareness of the important role they play in the ability of patients to adhere to rec- ommendations [13]. A study stated that adherence of low-sodium diet is influ- enced by the opinions of significant oth- ers/spouses, family members, nurse, phy- sicians, and other health care profession- als. Including family members in heart fail- ure treatment particularly regarding ad- herence to non-pharmacological measures appears to be crucial and has been gaining ground as a self-care strategy [14]. Moreo- ver, a recent US study found that patients with heart failure whose family members also followed a low-sodium diet were 1.6 times more likely to be adherent [15]. One of major contributing factor in continuing poor adherence to a low-sodium diet is lack of knowledge, because majority of patients not received a recommendation and information of sodium restricted diets (SRD) from health care providers. This in- dicates that health care providers simple recommendation may not be enough to motivate patient’s adherence behavior. Researchers suggested that lack of knowledge is a key barrier in diet adher- ence [16]. In this study, the highest pro- portion (80%) of patients had low knowledge and high barriers (66%) to ad- herence low-sodium diet which is support- ed by the study showing the overall adher- ence to sodium diet was poor [17]. Also another study found that 86% of heart failure patients were not aware of a SRD guideline, 42% could not determine sodi- um content from a nutrition label, and 56% could not distinguish high and low sodium foods [6].The result in this study reveals that poor adherence in SRD in HF patients is still problematic and health care providers need to attend to dietary sodium adherence to improve health out- come of HF patients. Diet education should be included strategies of how to follow a SRD guideline in daily life and strategies of how to overcome barriers of adherence to SRD. Patient education should be focused on understating how SRD adherence contributes their HF man- agement. Many studies simply do not re- port associations between demographic variables and adherence; thus, it is im- portant to continue to explore whether and how these variables are related to adherence. In the present study there is a significant association found between age group and knowledge (p-value=0.01) and perceived barrier (p-value=0.04) to low sodium diet adherence which is sup- ported by study that found that age is positively related to adherence [18]. While study have reported no association between age and adherence to low sodi- um diet [19]. Gender is significantly asso- ciated with knowledge (p-value= <0.001) and perceived barrier to low sodium diet adherence (p-value=0.05). Another study revealed that women are less adherent than men [20] possibly due to lifestyle alterations that involve shopping for and preparing meals might be harder for men to make and traditional domestic roles that call for the wife to prepare meals. Moreover, concerning educational level there was a significant association be- tween level of education with knowledge and perceived barrier to low sodium diet adherence, p-value= <0.001 and p-value =0.02 respectively, reported that number of years of education and adherence were significantly positively related [21]. The findings of present study shows there was is significant association between economic status and knowledge https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article 54 Erbil Journal of Nursing & Midwifery (p-value= <0.001) and barrier (p- value=0.001).A study reported that in- come was negatively related to low-salt diet adherence is surprising, as one might expect that those who are more affluent are more likely to seek out and afford healthier foods, and thus would be more adherent to a low-salt diet [22]. The study showed that higher proportion of heart failure patients were older age, male, had low levels of education, were having insufficient economic status, most of them hospitalized in last year, majority of patients had symptomatic and function- ally compromised (New York Heart Associ- ation NYHA classes II and III) and high pro- portion of the patients had co-morbidity (hypertension, coronary artery disease and diabetes mellitus). In general, most of patients had poor knowledge and more barriers to adherence to low-sodium diet. There was a significant association be- tween heart failure knowledge and barrier with age group, gender, level of education, economical status. I declare that there is no conflict of inter- est in this study [1] Smeltzer, S. C, Bare, B. G, Hinkle, J. L., and Cheever, K. H., (2010). Brunner & Suddarth’s Textbook of Medical-Surgical Nursing, 12th edition, Lippincott Williams &Wilkins. Phila- delphia, USA. p.1197. [2] Ko DT, Alter DA, Austin PC, You JJ, Lee DS, Qiu F, et al. Life expectancy after an index hospitalization for patients with heart failure: a population-based study. American Heart Journal. 2008; 155(2):324-31. doi: 10.1016 [3] Dickstein K, Cohen-Solal A, Filippatos G, McMurray JJ, Ponikowski P, Poole-Wilson PA. ESC guidelines for the diagnosis and treatment of acute and chronic heart fail- ure, the Task Force for the diagnosis and treatment of acute and chronic heart fail- ure of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association of the ESC (HFA) and endorsed by the European Society of Inten- sive Care Medicine (ESICM). European Jour- nal Heart Failure. 2008;10(10);933–89. [4] Bentley B, Lennie TA, Biddle M, Chung ML, and Moser DK, . Demonstration of psycho- metric soundness of the Dietary Sodium Restriction Questionnaire in patients with heart failure. Heart Lung Journal. 2009;38 (2):121-8. doi: 10.1016. [5] Arcand, J, Ivanov J, Sasson A, Floras V, Al- Hesayen A, Azevedo ER, et al. A high- sodium diet is associated with acute de- compensated heart failure in ambulatory heart failure patients: a prospective follow- up study. The American Journal of Clinical Nutrition. 2002 143(1):29-33. pub- med/11773909 [6] Neily J B, Toto K H, Gardner E B, Rame J.E , Yancy CW. Sheffield MA.,, et al. Potential contributing factors to noncompliance with dietary sodium restriction in patients with heart failure. American Heart Jour- nal.2002;143(1):29–33. [7] Lennie TA, Carter LW, Hammash M, Forren JO, Roser LP, Smith CS, etal. Relationship of Heart Failure Patients’ Knowledge, Barriers Regarding Low- Sodium Diet Recommenda- tions to Adherence. Progress in Cardiovas- cular Nursing. 2008;23(1):6-11. [8] Paterna S, Parrinello G, Cannizzaro S, Fasullo S, Torres D, Sarullo FM, et al. Me- dium term effects of different dosage of diuretic, sodium, and fluid administration on neurohormonal and clinical outcome in patients with recently compensated heart failure. American Journal of Cardiology 2009; 103(1):93–102. [9] Araoye MO Research Methodology with Statistical for Health and Social sci- ence .Nathadex publisher Iorin, 2003; P.1-9. [01] Dickson VV, Lee, CS. and Riegel B. How Do Cognitive Function and Knowledge Affect Heart Failure Self-Care? Journal of Mixed Methods Research. 2011; 5(2) 167–189 [00] Lennie TA, Chung ML, Moser DK. What Should We Tell Patients with Heart Failure about Sodium Restriction and How Should We Counsel Them? Current Heart Failure Reports Journal. 2013; 10(3): 219–226. CONCLUSION CONFLICT OF INTEREST REFERENCES https://doi.org/10.15218/ejnm.2020.06 Erbil j. nurs. midwifery, Vol. 3, No. (1), May, 2020 Original Article 55 Erbil Journal of Nursing & Midwifery [12] Bennett SJ, Cordes DK, Westmoreland G, Castro R, Donnelly E. Self-care strategies for symptom management in patients with chronic heart failure. Nursing Research Jour- nal. 2000;49(3):139–145. [13] Chung ML, Moser DK, Lennie TA, Worrall- Carter L, Bentley B, Trupp R, et al. Gender differences in adherence to the sodium- restricted diet in patients with heart failure. Journal of Cardiac Failure. 2006 Oct; 12(8): 628. doi: 10.1016/j.cardfail.2006.07.007 [14] Welsh D, Lennie TA, Marcinek R, Biddle MJ, Abshire D, Bentley B, , et al. Low- sodium diet self management intervention in heart failure: pilot study results. Europe- an Journal Cardiovascular Nursing. 2013; 12 (1): 87-95. PMid:22492785 [15] Chung ML, Lennie TA, Mudd-Martin G, Moser DK. Adherence to a low sodium diet in patients with heart failure is best when family members also follow the diet: a multicenter observational study. The Jour- nal of Cardiovascular Nursing. 2015; 30(1): 44-50. PMid:24165698 [16] Chung ML, Moser DK, Lennie TA, Worrall- Carter Li, Bentley B and Trupp R, et al Gen- der differences in adherence to the sodium- restricted diet in patients with heart failure. Journal Cardiac Failure. 2006; 2(8): 628. doi:10.1016/j.cardfail. 07.007. [17] Evangelista LS, Berg J, Dracup K. Relation- ship between psychosocial variables and compliance in patients with heart failure. Heart & lung: the Journal of Critical Care. 2001; 30(4):294–301. [PubMed: 11449216] [18] Maguire LK, Hughes CM, McElnay JC. Explor- ing the impact of depressive symptoms and medication beliefs on medication adher- ence in hypertension-A primary care study. Patient Education and Counseling. 2008;73 (2):371-6. doi: 10.1016/j.pec.2008.06.016. [19] Wu JR, Moser DK, Lennie TA, and Burkhart PV. Medication adherence in patients who have heart failure: a review of the litera- ture. The Nursing Clinics of North America 2008;43(1):133-53; vii-viii. doi: 10.1016/ j.cnur.2007.10.006. [21] Chapman RH, Benner JS, Petrilla AA, Tierce JC, Collins SR, Battleman DS, et al. Predic- tors of adherence with antihypertensive and lipid-lowering therapy. Archives of Internal Medicine,2005;165,1147- 1152.PubMed: v116n4,Oct. 1965-v172n22, Dec. 2012. [21] Bane C, Hughes CM, and McElnay JC. The im- pact of depressive symptoms and psychoso- cial factors on medication adherence in car- diovascular disease. Patient Education and Counseling, 2006; 60(2), 187-193. [22] Khanderia U, Townsend KA, Erickson SR, Vlasnik J, Prager RL, and Eagle KA. Medica- tion adherence following coronary artery bypass graft surgery: Assessment of beliefs and attitudes. The Annals of Pharmacother- apy, 2008 ;42(2):192-9. doi: 10.1345/ aph.1K497. Epub 2008 Jan 15.