Medication non-adherence in patients with heart failure: A systematic review

Abstract

Medication non-adherence is a major cause of hospitalization in heart failure (HF) patients. Studies have reported high rates of non-adherence to treatment in patients with HF. Therefore, this review was conducted to investigate the factors associated with medication non-adherence in patients with HF. This systematic review was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) (2020). All scientific articles in the field of medication non-adherence in HF patients were searched in international databases, such as ISI Web of Science, Scopus, PubMed, Google Scholar, and ScienceDirect. Searches were conducted among the studies conducted from April 2015 to August 2024 using the keywords of medication non-adherence, HF, non-adherence to treatment, adherence to treatment, and medication adherence alone or in combination, and using AND and OR mediations. After evaluating the eligibility criteria and the quality of the articles, 20 articles were classified and analyzed for content. The information resource management software (Endnote 9325 Bld 7.5, X, Reuters Thomson). The articles were descriptive cross-sectional, cohort, and observational. The sampling method was census in 12 articles and convenience in eight other articles. The sample size varied from 72 to 26,439 subjects. In most of the studies reviewed, the rate of medication non-adherence in HF patients was greater than 50%. After reviewing the studies, the factors related to medication non-adherence in HF patients were categorized into three dimensions, including: 1) individual factors, 2) clinical factors, and 3) social support factors. Considering the factors associated with medication non-adherence in patients with HF, it is suggested that governments, physicians, nurses, and workers identify the causes of medication non-adherence in these patients by providing health insurance, training, and free counseling to help the patients solve these problems. In doing so, they will help these patients improve their self-care and medication adherence, thereby improving their quality of life.

Introduction

Heart failure (HF) is a chronic disease that often results in significant impairment of the cardiovascular system.[1] Epidemiologic data show that HF affects approximately 2% of the adult population in developed countries.[2] In the United States alone, approximately 6.7 million people aged 20 years and older have HF, and this number is expected to increase to 8.5 million by 2030.[3] The prognosis of this disease is poor, with approximately 283,000 people worldwide dying from HF each year and a 26% increase in HF hospitalizations over the past decade.[1] Results of a study by Goudarzi et al. (2020)[4] showed that 25% of readmissions due to this condition occur in the first 30 days after discharge, and nearly 50% of readmissions occur within 6 months of discharge. Causes of rehospitalization include failure to perform routine tests, such as echocardiography and medication non-adherence.[3,4]

Medication non-adherence is a major cause of hospitalization in HF patients. Adherence is one of the disease-related behaviors that is defined as the degree to which people’s behaviors comply with health and treatment recommendations.[5]

Adherence to treatment plans and prescribed medications is an important challenge for patients with chronic diseases. If they do not adhere to treatment plans, these patients will suffer from the dire consequences, including disease recurrence and disability progression, and will require urgent treatment and hospitalization.[6] In a study, the rate of non-adherence to treatment in patients with HF was reported to be 74.7% and low.[7] In general, 20–50% of patients with chronic diseases and 40–60% of patients with HF do not adhere to their medications.[8] The main treatment programs for patients with cardiovascular disease include exercise, taking medications as directed, and following a recommended diet and lifestyle.[6] Therefore, adherence to treatment and medication regimens in patients with heart disease includes both medication and non-medication adherence that the patient must observe. However, when patients with HF leave the hospital and return to the community, the main problem they face is premature discontinuation of medication and non-adherence to medical advice, which is the leading cause of death after discharge.[5]

Theoretical model to explain medication non-adherence

The new theoretical model to explain medication non-adherence is Hierarchical Model for Medication Adherence (HMMA). It is based on Maslow’s Hierarchy of Needs theory, where a person acquires certain skills/beliefs/behaviors at lower levels to achieve a higher level of medication adherence behavior. According to this model, every person should have sufficient health literacy at first. Then, the patient must accept her/his illness and to believe that medication adherence will make her better. The final stage of this model is self-efficacy. Even if a person has sufficient health literacy and has positive beliefs, he/she should still be self-efficacious.[8] [Figure 1].

Figure 1.

Hierarchical Model of Medication Adherence

Given the importance of adherence to treatment and the awareness that many patients do not adhere to treatment plans, identifying the factors that influence non-adherence and attempting to address them can improve patient adherence and also improve the quality of care. The review studies conducted so far are on medication adherence, and the causes of non-adherence in patients with HF have not been investigated. Therefore, this review was conducted to investigate the factors associated with medication non-adherence in patients with HF.

Materials and Methods

Design

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews on Meta-Analyses (PRISMA) guidelines (2020).[9] The study population consisted of all scientific articles on medication non-adherence in HF patients that were indexed in one of the Internet databases.

Selection or eligibility criteria

Inclusion criteria were as follows: publication in English, access to full-text articles, original research articles (including descriptive, analytical, observational, and cohort articles), and at least one outcome variable, such as medication non-adherence in HF patients, could be identified in the title or abstract of the article. Exclusion criteria included case studies, qualitative studies, review articles, and letters to the editor because they did not use primary data.

Search strategy

The search was conducted by the researchers in international databases, such as ISI Web of Science, Scopus, PubMed, Google Scholar, and ScienceDirect. Searches were conducted using the keywords of medication non-adherence, HF, non-adherence to treatment, adherence to treatment, and medication adherence alone or in combination, and using AND and OR mediations, considering the period from April 2015 to August 2024. For example, the search strategy in PubMed and ISI databases was based on the following combination:

(Medication Non-Adherence * OR Non-Adherence to treatment * OR Medication Adherence * OR Adherence to treatment *) AND (Heart Failure OR HF *) AND (patient OR client)

Study screening

As the researcher carefully studied the title and abstract of the articles that met the inclusion criteria, a large number of them were excluded due to weak or unrelated relevance to the purpose of the study. The full text was referenced if it was not possible to make a decision about the article after reading the title and abstract. To ensure that all documents were retrieved, the list of each article’s resources was also searched. By using the mentioned software and reviewing the titles and abstracts of the articles, 545 duplicate studies were removed. After reviewing the purpose of the studies and the inclusion criteria, 23 studies were separately assessed for quality by two researchers.

Data extraction and synthesis

The search yielded 856 studies. The information resource management software (EndNote 9325 Bld 7.5, X, Reuters Thomson) was used to organize the studies.

Quality assessment

The revised Newcastle-Ottawa Scale (observational studies version 9) was used to assess the quality of these articles. This scale assesses articles in terms of selection process (in four sections, including sample homogeneity, sample size, non-response, and measurement instruments), comparability (examination of confounders and other influencing factors), and results (in two aspects of outcome assessment and statistical testing). Based on the Newcastle-Ottawa Scale, articles are rated from 0 (the weakest study) to 10 (the strongest study). To preserve the data, studies with a score below the mean (lower than 4) were considered low quality. Therefore, two articles were removed due to low quality and one article was removed due to repetitive content and re-reporting of information in the form of a new article,[10,11,12] leaving 20 studies to be reviewed. The articles of various databases included ISI Web of Science (three articles), Scopus (seven articles), PubMed (six articles), Google Scholar (two articles), and ScienceDirect (two articles). Figure 2 illustrates the process of entering studies into the research.

Figure 2.

PRISMA (2020) flowchart

The quality assessment of the articles according to the Newcastle-Ottawa Scale is shown in Table 1. All stages of quality assessment of articles were performed by two researchers (NMA and PSB), and in case of disagreement, they were reviewed by a third researcher (AS).

Table 1.

Evaluation of the quality of articles eligible for inclusion in the study using the Newcastle-Ottawa scale (NOS)

Author (year)		Selection		Comparability		Outcomes		Total NOS
Kukulska et al., 2024[13]		****		-		***		7
Deek & Massouh, 2024[14]		***		*		**		6
Betancourt-Peña et al., 2024[15]		***		-		**		5
Ødegaard et al., 2023[10]		**		-		*		3
Huber et al., 2023[16]		****		*		***		7
Jarrah et al., 2023[17]		****		-		***		7
Seid et al., 2023[18]		****		-		****		8
Rezaei et al., 2022[19]		***		-		**		5
Kawada et al., 2022[20]		**		-		**		4
Jaarsma et al., 2021[21]		**		-		**		4
Olagoke Korede et al., 2021[22]		***		-		***		6
Rasmussen et al., 2021[23]		**		*		****		7
Gupta et al., 2021[24]		***		*		**		6
Raffaa et al., 2020[25]		***		-		***		6
Pallangyo et al., 2020[7]		****		-		****		8
Oscalices et al., 2019,[26]		***		-		****		7
Chang et al., 2019[27]		**		-		**		4
Amininasab et al., 2018[28]		***				**		5
Hood et al., 2018[11]		**		-		*		3
Dolansky et al., 2016[29]		**		-		***		5
Dickson et al., 2015[30]		**		*		*		4
Juarez et al., 2015[12]		*		-		**		3
da Silva et al., 2015[31]		**		-		**		4

To summarize the studies, the full text of each article was read, and then, a summary was taken from it. Given the potential for error and bias in sampling, data collection, and reporting of results across studies, those factors were considered important that were cited by more than 40% of HF patients as reasons for non-adherence to treatment. The information obtained from the articles was classified, compared, and summarized according to the objectives of the study. Microsoft Excel 2007 software was used for this purpose. The items extracted from the studies included the first author’s name, year of publication, study location, study type, sample size, the scale for measuring non-adherence to treatment, and overall result. The features of the reviewed articles are shown in Table 2.

Table 2.

Characteristics of the reviewed articles related to the causes of medication non-adherence in HF patients

Author (year)		Country		Type of research		Sample size		Scale		Result
Kukulska et al., 2024[13]		Poland		Cross-sectional study		105		Adherence in chronic diseases scale (ACDS)		26.67% displayed low adherence. Factors, such as obesity, respiratory diseases, and frequent HF-related hospitalizations, were associated with non-adherence in HF patients.
Deek & Massouh, 2024[14]		Beirut, Lebanon		Cross-sectional study		237		Lebanese Medication Adherence Scale		Non-availability of the medications and the absence of financial resources or not having a caregivers were associated with non-adherence in HF patients
Betancourt-Peña et al., 2024[15]		Colombia, America		Observational and retrospective study		300		Adherence to cardiac rehabilitation		High blood pressure, LDL, triglycerides, and depression were related factors for not having adherence to cardiac rehabilitation in patients with heart failure.
Huber et al., 2023[16]		Switzerland		Cross-sectional study		72		Medication Adherence Report Scale (MARS-5)		26.4% were not fully adherent. Their most common reason was forgetfulness (23.7%). Also, rehospitalization was cases non-adherence in HF patients.
Jarrah et al., 2023[17]		Jordan		Cross-sectional study		164		Medication Adherence Scale		The reason for non-adherence to treatment in HF patients was neglect of treatment, drugs side effects, high number of pills, and high treatment costs.
Seid et al., 2023[18]		Ethiopia, Africa		Cross-sectional study		254		Medication Adherence Report Scale (MARS-5)		The presence of comorbid illness, taking three or more types of medication, and being unmarried was associated of medication non-adherence.
Rezaei et al., 2022[19]		Iran		Cross-sectional study		250		Morisky-Green test and the Brief Medical Questionnaire		The results showed that most patients with heart failure had low medication adherence. Some factors, including gender, health literacy, and duration of illness and health literacy, were associated with adherence.
Kawada et al., 2022[20]		Japan		Retrospective observational study		824		Medication Adherence Report Scale 5-items		Low social support, high hospitalization, and dementia associated with non-adherence. Male patients or current smokers had more non-adherence.
Jaarsma et al., 2021[21]		Sweden		Cross-sectional study		305		Data collected Hospital Anxiety and Depression Scale, Exercise Motivation Index, Montreal Cognitive Assessment, Minimal Insomnia Symptom Scale, and Exercise Self-efficacy Scale.		The reason for non-compliance with the treatment was the patient’s anxiety and depression, lack of motivation, insomnia, and cognitive and behavioral problems of the patient.
Olagoke Korede et al., 2021[22]		Nigerian		Descriptive cross-sectional study		202		Medication Adherence Report Scale 5-items		Medication non-adherence was associated with age, gender, educational status, pill burden, duration of HF, history of HF admission, functional status, and specific comorbidities.
Rasmussen et al., 2021[23]		Denmark		Cohort study		1464		EuroQol five-dimensional, five-level questionnaire (EQ-5D-5L), the HeartQoL, and the Hospital Anxiety and Depression Scale (HADS).		Lower health-related quality of life and symptoms of depression were associated with non-adherence across HF medications at 1 and 3 years of follow-up.
Gupta et al., 2021[24]		United Kingdom		Prospective multicenter study		1296		Liquid chromatography-mass spectrometry (LC-MS/MS)1		There is the relationship between medication non-adherence hospitalization over a median follow-up of 21 months. Non-adherence to at least one prescribed medication was observed in 45.9% of patients which was caused by some drugs or drug side effects. Beta-blockers were the most drugs that were not used by HF patients.
Raffaa et al., 2020[25]		Southern Saudi Arabia		Descriptive cross-sectional study		151		Questionnaire developed by the researcher include comorbidities and disease-related data and drugs.		About 49% of the patients forget to have their medication at least once, while 34.4% had problems remembering to take your medication. Totally, 53.6% of the patients had poor medication adherence. Low income, low education, being single, urban residence, and lack of knowledge are related to medication non-adherence.
Pallangyo et al., 2020[7]		Tanzania		Prospective cohort study		459		Adherence data were gathered using a structured questionnaire during the hospital admission of enrollment.		74.7% had poor adherence. Residing in urban areas, obesity, suffering from other diseases, age, frequent hospitalizations, low education, similar medication, and low income are related to medication non-adherence. Other reported factors affecting adherence in this cohort included: medication side effects (8.1%), forgetfulness (53.9%), negligence (26.0%), local unavailability of drugs (18.9%), and pill burden (34.4%).
Oscalices et al., 2019[26]		Brazil		Cross-sectional, analytical study		100		Morisky-Green test and the Brief Medical Questionnaire		Medication adherence was low in 41.1%. The low level of literacy was directly related to lower adherence. Also, medication non-adherence is associated with residing in urban areas, obesity, have other diseases, age, frequent hospitalizations, low education, similar medication, and low income.
Chang et al., 2019[27]		America		Cohort study		26439		The proportion of days covered (PDC) algorithm		Medication adherence was low in 51.1%. The low education, age, sex (female), age 65>patients, and low income was associated with medication non-adherence.
Amininasab et al., 2018[28]		Iran		Cross-sectional study		300		Morisky Medication Adherence Scale		Medication adherence had a significant correlation with education level, number of children, comorbidity ejection fraction, and the number of tablets used per day. Medication non-adherence had significantly correlated with age, gender, employment status, place of residence, income level, and the number of hospitalizations for heart failure.
Dolansky et al., 2016[29]		Cleveland, America		A prospective observational cohort design		309		Medication adherence was measured objectively using MedSignals® Pillbox (VitalSignals, LLC, Lexington, KY).		Medication non-adherence is associated with age, education level, self-reported current heart failure severity, medical comorbidity, depressed mood, anxiety, social support, and health literacy, income. Also, cognitive impairment, and memory in particular, is associated with medication non-adherence in patients with HF.
Dickson et al., 2015[30]		New York		Prospective cohort comparison study		212		The Medication Event Monitoring System (MEMS™; MVW Switzerland Ltd., Sion, Switzerland)		Medication non-adherence was different among Black and White patients with HF. Medication non-adherence was more common in Blacks than White patient that it was associated with age, more comorbidities, lower serum sodium, higher systolic blood pressure, and use of fewer activities compensating for forgetfulness.
da Silva et al., 2015[31]		Brazil		Cross-sectional study		340		10-item questionnaire adherence		Presence of hypertension, no having social support, and lived without family were associated with medication non-adherence.

¹LC-MS/MS is an objective new technique to assess non-adherence to medications.

Ethical consideration

The research was approved by the Kashan University Ethics Committee. Research code: (402083).

Result

Finally, we reviewed 20 articles that were descriptive cross-sectional studies, cohort studies, and observational studies. The sampling method was census in 12 articles and convenience in eight other articles. The sample size varied from 72 to 26,439 subjects. In most of the studies reviewed, the rate of medication non-adherence in HF patients was greater than 50%. Several questionnaires have been used to investigate medication non-adherence and the factors associated with it. The characteristics of the studies reviewed are shown in Table 2.

After reviewing the studies, the factors related to medication non-adherence in HF patients were categorized into three dimensions, including: 1) individual factors, 2) clinical factors, and 3) social support factors. In some studies, the above factors were reported as a combination, which is described separately below [Table 3].

Table 3.

Factors associated with medication non-adherence in HF patients

Dimension		Factors associated with medication non-adherence		Studies reference
Individual factors		Age over 65 years		[22,26,27,28,29,30]
		Gender (male)		[7,22,29]
		Low education		[7,22,26,27,28,29,30]
		Low income		[7,22,25,26,27,28]
		Being single		[17,22,25,26,28]
		Living in the village		[25,26,28]
		Low health literacy		[19,22,25,29]
		Having chronic diseases		[15,21,22,23,26,27,28]
		Obesity		[13]
Clinical factors		A high number of drugs		[7,17,18,24,28]
		Side effects of drugs		[7,17,24]
		Similarity of drugs to each other		[7]
		Frequent hospitalizations due to HF		[7,13,16,20,26,28]
		Low ejection fraction of the heart		[28]
		Forgetfulness and negligence in taking medication		[7,16,21]
		Severity of the disease		[19,26]
		Duration of the disease HF		[19,22]
		History of HF disease		[22]
Supportive-social factors		Lack of financial support from the government		[14,17]
		Lack of insurance support in the provision of some drugs		[14,17]
		High costs of treatment and diagnostic tests		[14,17]
		Lack of family support in treatment		[27,31]
		Not having a caregiver		[27,31]
		Living without family members		[27,31]

Individual factors

In 15 (75%) of the reviewed articles,[7,13,15,18,19,20,21,22,23,25,26,27,28,29,30] individual factors, such as age, sex, education, income, marriage, residence, chronic disease, obesity, and health literacy, were among the causes of medication non-adherence. The results of the studies conducted by Oscalices et al. (2019),[26] Olagoke Korede et al. (2021),[22] Amininasab et al. (2018),[28] and Chang et al. (2019)[27] indicated that medication non-adherence in HF patients was associated with age (>65 years), sex (male), low education, rural residence, low income, and having multiple chronic diseases. According to the reviewed studies, the causes of medication non-adherence in HF patients included age over 65 years,[22,26,27,28,29,30] sex (male),[7,22,29] low education,[7,22,25,26,27,28,29] low income,[7,22,25,26,27,29] being single,[18,22,25,26,28] rural residence,[25,26,28] low health literacy,[19,22,25,29] having chronic diseases,[15,21,22,23,26,27,28] and obesity[13] [Table 2].

Clinical factors

In 15 of the reviewed articles,[7,13,15,16,17,18,19,20,21,22,24,26,27,28,29,30,31] clinical factors, such as large number of medications, side effects of medications, similarity of medications, repeated hospitalizations due to HF, low cardiac ejection fraction, forgetfulness and negligence in taking medications, disease severity, duration of HF, and history of HF, were reported as causes of medication non-adherence in HF patients. Studies have reported that the causes of medication non-adherence in HF patients include the large number of medications,[7,17,18,24,28] medication side effects, such as excessive urination due to the use of diuretics or complications related to beta-blockers,[7,17,24] similarity of medications,[7] frequent hospitalization for HF,[7,13,16,20,26,28] low cardiac ejection fraction,[28] forgetfulness and negligence in taking medications,[7,16,21] severity of disease,[19,26] duration of HF,[19,22] and history of HF[22] [Table 2].

Social support factors

In four studies,[14,17,29,31] social support factors, such as lack of financial support from the government, lack of family support in treatment, lack of care, lack of insurance support, high cost of treatment, and living without family members, are the reasons for medication non-adherence in HF patients. For example, studies by Deek and Massouh[14] and Jarrah et al.[17] showed that lack of financial support from the government, lack of insurance support for some medications, and high costs of treatment and diagnostic tests are the reasons for medication non-adherence in HF patients. In addition, studies by Dolansky et al.[29] and da Silva et al.[30] reported that lack of family support in treatment, having no caregiver, and living without family members were causes of medication non-adherence in HF patients.

Discussion

The aim of this study was to determine the factors associated with medication non-adherence in patients with HF. Based on the results of this review, patients with HF had low medication adherence, and the causes of this non-adherence were classified into three categories of individual factors, clinical factors, and social support factors. As revealed by the results of this study, age was one of the individual factors associated with medication non-adherence. Studies have shown that medication adherence decreases in HF patients over the age of 65. Medication adherence diminishes in these patients because of forgetfulness or dementia, cognitive problems, and many chronic diseases, such as hypertension and diabetes.[22,26,27,28,29,30] Another study reported that having multiple chronic conditions and a large number of pills affects patients’ adherence to medications and may cause confusion in taking medications.[16] Our review also found that in Tanzania and Nigeria, as well as in the city of Cleveland, USA, men and smokers have more medication non-adherence than women.[7,22,29] In contrast, there was more medication non-adherence in women with HF according to the results of the study by Amininasab et al., 2018[28] in Iran. Perhaps the reason for the various roles of gender is the different culture of patients in different countries, which affects medication adherence.[32] This study showed that patients with medication non-adherence had low education[7,22,25,26,27,28,29] and low health literacy.[19,22,25,29] Studies show that patients with higher levels of education are more aware of their health and adhere better to their medications.[7,22,32] Higher levels of education lead to an increase in medication adherence by increasing patients’ awareness and knowledge of their disease.[33] This study also found that living in rural areas and having low income were among the factors associated with medication non-adherence in HF patients. Some studies have reported higher levels of medication non-adherence in rural areas due to distance from the city and lack of access to diagnostic and treatment facilities.[25,34] Other studies have reported that low income and high cost of care, and long distance from the village to the city to see a doctor, are among the factors of medication non-adherence in cardiac patients.[34,35] Therefore, it seems that in the care and treatment of these patients, specific attention should be paid to their individual characteristics and counseling programs should be planned for them according to these characteristics.

Studies have shown that the large number of medications and multidrug use in HF patients has led to medication non-adherence in these patients.[7,17,18,24,28] Studies in this area have reported that the large number of medications and their similarity cause patients to forget or neglect their use.[7,16,21] In a qualitative study, cardiac patients reported that one of the reasons they forgot to take their medications was that there were too many pills and they were similar.[36] In this review, the results of the studies showed that the fear of the side effects of the medications led to more medication non-adherence among the patients.[7,17,24] In a qualitative study, patients stated that they arbitrarily reduced their diuretic dose because of its side effects and excessive urine.[37] The results of another study showed that patients with HF arbitrarily reduced or discontinued the dose of beta-blockers.[24] Therefore, there is a need for patient education in this area. This review revealed a relationship between multiple hospitalizations of patients and medication non-adherence.[7,13,16,20,26,28] As reported in the research of Huber et al. (2023), heart patients do not adhere to treatment due to frequent hospitalizations and physical problems caused by the disease.[16] Perhaps the reason is that they think their death is imminent and they have no hope of treatment. This review also showed that disease severity,[19,26] duration of HF,[19,22] and history of HF[22] were associated with medication non-adherence. Thus, the greater the severity and duration of the disease, the greater would be the non-adherence to treatment. Gourzoulidis et al. (2017)[38] reported that suffering from heart disease for a long period of time can cause people to neglect themselves, and due to the chronicity of the disease, they become tired of following their diet and medications. Another study reported that a person’s ability to care for themselves decreases as the severity of the disease increases.[39] Moreover, Sadeghiazar et al. (2022)[40] found that patients with a family history of chronic disease are more sensitive to their treatment because they know the complications of the disease. The results of their study are not consistent with this review. These different results may be due to the different cultures of the families and the personality characteristics of the patients. Therefore, more attention should be paid to the clinical factors mentioned in the consultation and treatment of these patients so that they can achieve a high degree of treatment and medication adherence. Deek and Massouh[14] and Jarrah et al.[17] showed that lack of financial support from the government, lack of insurance support for some medications, and high costs of treatment and diagnostic tests are the reasons for medication non-adherence in HF patients. Consistent with this study, Iuga and McGuire reported in a study that cardiac patients neglect to take their medications and undergo diagnostic tests, such as echocardiography and electrocardiography due to the lack of travel costs to the doctor, the high cost of medications, and the lack of government and insurance support in this area.[41] Therefore, it seems that governments need to take action in this area due to the high cost of treating heart patients. Similarly, studies by Dolansky et al.[29] and da Silva et al.[31] reported that lack of family support in treatment, having no caregiver, and living without family members were causes of medication non-adherence in HF patients. Consistent with this review, studies have reported that cardiac patients need a caregiver with sufficient knowledge in the field of medicine and treatment of this disease.[41,42] Another study reported that the knowledge and skills of families of cardiac patients should be improved in the area of care and treatment of these patients.[43] Numerous studies have reported various interventions, such as the use of family-centered and participatory models to improve the knowledge and skills of caregivers and the patient’s family in recognizing symptoms and taking immediate action, such as the use of nitroglycerin tablets.[44,45,46] Thus, it is important to pay attention to this factor in cardiac patients. Therefore, with the support of governments, it is necessary to identify vulnerable patients and provide them with an appropriate insurance and free counseling centers. It is also necessary for families who have a patient with HF to receive free training in the area of medical and therapeutic care of a patient with HF.

The strength of this study is that it used PRISMA guidelines. This study included different types of electronic databases and published studies.

Limitations

The limitations of this study included the exclusion of articles published in languages other than English, and the lack of access to the full texts of some articles.

Conclusion

As revealed by the results of this review, patients with HF had low medication adherence, and the causes of this non-adherence were classified into three categories of individual factors, clinical factors, and social support factors. This research by identifying the factors related to non-adherence to medication in HF patients will help health policy makers to take necessary measures to eliminate these factors while trying to improve the health of these patients. It is also recommended to design a tool for the causes of medication non-adherence in HF patients based on the obtained components.

Conflicts of interest

Nil.

Funding Statement

Kashan university of medical sciences.