Evaluation of the effects of health education interventions for hypertensive patients based on the health belief model

Abstract

BACKGROUND

Hypertension is a major risk factor for cardiovascular disease and stroke, and its prevalence is increasing worldwide. Health education interventions based on the health belief model (HBM) can improve the knowledge, attitudes, and behaviors of patients with hypertension and help them control their blood pressure.

AIM

To evaluate the effects of health education interventions based on the HBM in patients with hypertension in China.

METHODS

Between 2021 and 2023, 140 patients with hypertension were randomly assigned to either the intervention or control group. The intervention group received health education based on the HBM, including lectures, brochures, videos, and counseling sessions, whereas the control group received routine care. Outcomes were measured at baseline, three months, and six months after the intervention and included blood pressure, medication adherence, self-efficacy, and perceived benefits, barriers, susceptibility, and severity.

RESULTS

The intervention group had significantly lower systolic blood pressure [mean difference (MD): -8.2 mmHg, P < 0.001] and diastolic blood pressure (MD: -5.1 mmHg, P = 0.002) compared to the control group at six months. The intervention group also had higher medication adherence (MD: 1.8, P < 0.001), self-efficacy (MD: 12.4, P < 0.001), perceived benefits (MD: 3.2, P < 0.001), lower perceived barriers (MD: -2.6, P = 0.001), higher perceived susceptibility (MD: 2.8, P = 0.002), and higher perceived severity (MD: 3.1, P < 0.001) than the control group at six months.

CONCLUSION

Health education interventions based on the HBM effectively improve blood pressure control and health beliefs in patients with hypertension and should be implemented in clinical practice and community settings.

Key Words: Hypertension, Health education, Health belief model, Blood pressure control, Randomized controlled trial

Core Tip: Health education interventions based on the health belief model (HBM) significantly improve blood pressure control and health beliefs in patients with hypertension. This study, conducted in China from 2021 to 2023, demonstrated that patients who received HBM-based education had lower blood pressure, better medication adherence, and improved self-efficacy than those who received routine care. Implementing such interventions in clinical and community settings can effectively help patients with hypertension manage their condition and enhance their overall health outcomes.

INTRODUCTION

Hypertension, also known as high blood pressure, is a chronic condition that occurs when the blood force acting on the arterial walls is excessively high[1]. Hypertension can damage blood vessels and organs and increase the risk of cardiovascular disease (CVD) and stroke[2]. According to the World Health Organization, hypertension affects approximately 1.13 billion people worldwide and is responsible for 10.4 million deaths annually[3]. In China, hypertension is a major public health problem, with an estimated prevalence of 23.2% among adults, a low awareness rate of 48.2%, a low treatment rate of 40.7%, and a low control rate of 15.3%[4]. Therefore, effective prevention and management of hypertension are essential to reduce the burden of CVD and stroke in China.

Health education is one of the key strategies for preventing and controlling hypertension, as it can improve the knowledge, attitudes, and behaviors of patients with hypertension and help them adopt healthy lifestyles and adhere to medications[5]. The health belief model (HBM) is a widely used theoretical framework for health education interventions that posits that health behaviors are influenced by six constructs: Perceived susceptibility, perceived severity, perceived benefits, perceived barriers, self-efficacy, and cues to action[6]. Perceived susceptibility refers to the belief that one is at risk of developing a disease or experiencing negative consequences; perceived severity refers to the belief that the disease or its consequences are serious or harmful; perceived benefits refer to the belief that taking a certain action will reduce the risk or severity of the disease or its consequences; perceived barriers refer to the belief that there are obstacles or costs associated with taking a certain action; self-efficacy refers to the belief that one has the ability or confidence to perform a certain action; and cues to action refer to the factors that trigger or motivate one to take a certain action[7]. According to the HBM, health behaviors are more likely to occur when individuals perceive a high susceptibility to and severity of a disease, perceive more benefits than barriers to taking action, have high self-efficacy, and receive cues for action[8].

Several studies have applied the HBM to design and evaluate health education interventions for patients with hypertension in different settings and populations[9-15]. The results showed that health education interventions based on the HBM could improve the blood pressure control and health beliefs of patients with hypertension compared with usual care or other interventions. However, most of these studies have been conducted in developed countries or regions, such as the United States, Europe, and Taiwan, and there is a lack of evidence on the effectiveness of health education interventions based on the HBM for patients with hypertension in mainland China. Moreover, most of these studies used a single or limited mode of delivery for health education interventions such as lectures, brochures, or telephone calls. There is a need to explore the use of multiple and diverse modes of delivery for health education interventions based on the HBM, such as videos, counseling sessions, and online platforms.

Therefore, this study aimed to evaluate the effects of health education interventions based on the HBM on patients with hypertension in China from 2021 to 2023.

MATERIALS AND METHODS

Study design and setting

This randomized controlled trial was divided into the intervention and control groups. This study was conducted at two health centers in the Lishui Second People's Hospital from January 2021 to June 2023. The choice of community health centers was based on their willingness to participate and the similarity of population size, socio-economic status, and medical service provision. The research plan was approved by the ethics committee of Lishui Second People's Hospital, and all participants provided written informed consent before enrollment.

Participants and sampling

The participants were patients with hypertension who met the following inclusion criteria: (1) Aged 18 years or above; (2) diagnosed with hypertension according to the 2018 Chinese guidelines for the management of hypertension (systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg, or taking antihypertensive medication)[16]; (3) registered as residents in the catchment area of community health centers; (4) able to communicate in mandarin and read and write Chinese; and (5) willing to participate in and follow the study procedures. The exclusion criteria were as follows: (1) Secondary hypertension or other serious co-morbidities such as heart failure, renal failure, or stroke; (2) cognitive impairment or mental disorders that could affect the understanding and completion of the questionnaires; and (3) participation in other similar health education interventions during the study period.

The sample size was calculated based on the primary outcome of systolic blood pressure. Assuming a mean difference of 10 mmHg between the intervention and control groups, a standard deviation of 15 mmHg, a significance level of 0.05, a power of 0.80, and a dropout rate of 20%, the required sample size was 64 patients per group. To achieve this sample size, 140 patients with hypertension were recruited from two community health centers using convenience sampling. The recruitment process was as follows: (1) The staff of the community health centers screened the eligible patients from their electronic medical records and contacted them by phone or home visits; (2) the staff explained the purpose and procedures of the study to the interested patients and obtained their written informed consent; (3) the staff collected the baseline data from the consenting patients using standardized questionnaires and measured their blood pressure using a calibrated electronic sphygmomanometer; (4) the staff randomly assigned the patients to either the intervention group or the control group using a computer-generated random number table; and (5) the staff informed the patients about their group allocation and provided them with relevant instructions.

Intervention

The intervention group received health education interventions based on the HBM, whereas the control group received routine care. The health education interventions consisted of four components: Lectures, brochures, videos, and counseling sessions. The lectures were delivered by trained nurses in a classroom setting at community health centers. The lectures covered topics such as the definition, causes, complications, prevention, and treatment of hypertension; the importance of medication adherence and lifestyle modification; and the application of HBM constructs to enhance self-efficacy and overcome barriers. The interactive lectures used various methods, such as demonstrations, role-plays, games, and quizzes, to engage participants. The lectures lasted approximately one hour each and were held once a month for three months. The brochures were designed based on the HBM constructs and contained information and tips for controlling blood pressure. Brochures were distributed to participants after each lecture and were made available online. The videos were produced by professional media companies and featured stories of patients with hypertension who successfully controlled their blood pressure by following the HBM principles[17]. The videos were shown to the participants during lectures and were made accessible online. The counseling sessions were conducted one-on-one by trained nurses at community health centers or via phone. The counseling sessions aimed to provide participants with individualized feedback, guidance, support, and reinforcement based on their blood pressure levels, medication adherence, lifestyle behaviors, and health beliefs. The counseling sessions lasted approximately 15 min each and were held once every two weeks for three months.

The control group received routine care in accordance with the National Guidelines for Hypertension Management in China[16]. Routine care included regular blood pressure monitoring, prescription medication, and general health education regarding the prevention and control of hypertension. The control group did not receive any specific interventions based on the HBM.

Data collection

Data were collected at baseline (before randomization), three months (after the intervention), and six months (follow-up) after the intervention. Data were collected by trained research assistants blinded to the participants’ group allocation. The data collection methods included questionnaires and blood pressure measurements.

Questionnaires were self-administered by the participants and contained questions on demographic characteristics, medication adherence, self-efficacy, as well as perceived benefits, barriers, susceptibility, and severity. Medication adherence was measured using the 8-item Morisky Medication Adherence Scale (MMAS-8), which assesses the frequency and reasons for missing or skipping medication doses[18]. The MMAS-8 has a total score ranging from 0 to 8, with higher scores indicating better medication adherence. Self-efficacy was measured using the 10-item Self-Efficacy for Managing Chronic Disease Scale, which assesses confidence in performing various self-management behaviors related to chronic diseases. The total score ranged from 10 to 100, with higher scores indicating higher self-efficacy. Perceived benefits, barriers, susceptibility, and severity were measured using the 16-item Hypertension Health Belief Scale, which assesses beliefs regarding the advantages and disadvantages of taking antihypertensive medications and lifestyle modifications, the likelihood and seriousness of developing hypertension-related complications, and the cues to action for blood pressure control. This scale has four subscales, each containing four items. Each item uses a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree). The subscale scores were calculated by summing the item scores, with higher scores indicating higher levels of the corresponding construct.

Trained research assistants measured the blood pressure using a calibrated electronic sphygmomanometer. The participants were instructed to sit quietly for at least 5 min before the measurement and avoid smoking, drinking caffeinated beverages, or exercising for 30 min before the measurement. Blood pressure was measured three times on the right arm at intervals of at least 1 min, and the average of the three readings was recorded as the blood pressure value. The systolic and diastolic blood pressures were recorded in millimeters of mercury (mmHg).

Data analysis

Data were analyzed using SPSS version 26.0. Descriptive statistics were used to describe the demographic characteristics, blood pressure, medication adherence, self-efficacy, and health beliefs of the participants in both groups at baseline and three and six months after the intervention. Independent t-tests or chi-square tests were used to compare the baseline differences between the two groups. Repeated-measures analysis of variance (ANOVA) or generalized estimating equations (GEE) were used to compare changes in blood pressure, medication adherence, self-efficacy, and health beliefs between the two groups over time. The level of significance was set at P < 0.05.

RESULTS

A total of 140 patients with hypertension were recruited and randomized into an intervention group (n = 70) and a control group (n = 70). The baseline characteristics of the study participants are presented in Table 1. There were no significant differences between the two groups in terms of age, sex, education level, marital status, occupation, smoking status, drinking status, body mass index, duration of hypertension, number of antihypertensive drugs, baseline blood pressure, medication adherence, self-efficacy, or health beliefs.

Table 1 Baseline characteristics of the participants, n (%)/mean ± SD.

Variable	Intervention group (n = 80)	Control group (n = 80)	P value
Age (yr)	58.6 ± 9.4	59.2 ± 10.2	0.64
Gender			0.87
Male	37 (52.9)	36 (51.4)
Female	33 (47.1)	34 (48.6)
Education level			0.76
Primary school or below	15 (21.4)	16 (22.9)
Middle school	31 (44.3)	30 (42.9)
High school or above	24 (34.3)	24 (34.3)
Marital status			0.81
Married or cohabiting	64 (91.4)	63 (90.0)
Single, divorced, or widowed	6 (8.6)	7 (10.0)
Occupation			0.69
Employed or self-employed	39 (55.7)	37 (52.9)
Retired or unemployed	31 (44.3)	33 (47.1)
Smoking status			0.92
Current smoker	11 (15.7)	10 (14.3)
Former smoker or never smoker	59 (84.3)	60 (85.7)
Drinking status			0.77
Current drinker	13 (18.6)	14 (20.0)
Former drinker or never drinker	57 (81.4)	56 (80.0)
Body mass index (kg/m2)	25.4 ± 3.2	25.7 ± 3.6	0.54
Duration of hypertension (yr)	8.3 ± 6.4	8.7 ± 7.2	0.71
Number of antihypertensive drugs			0.83
One	31 (44.3)	29 (41.4)
Two or more	39 (55.7)	41 (58.6)
Systolic blood pressure (mmHg)	149 ± 14	150 ± 15	0.67
Diastolic blood pressure (mmHg)	91 ± 9	92 ± 10	0.59
Medication adherence score
MMAS-8	6.2 ± 1.8	6.3 ± 1.9	0.68
Self-efficacy score
SEMCDS	68.4 ± 1.7	68.6 ± 1.8	0.51
Perceived benefits score
HHBS	16.8 ± 2.4	16.9 ± 2.6	0.32
Perceived barriers score
HHBS	11.2 ± 3.1	11.4 ± 3.3	0.49
Perceived susceptibility score
HHBS	14.6 ± 2.9	14.7 ± 3.1	0.56
Perceived severity score
HHBS	15.4 ± 2.7	1 .5 ± 2.8	0.68

P values are based on independent t-tests or chi-square tests. MMAS-8: Morisky medication adherence scale; SEMCDS: Self-efficacy for managing chronic disease scale; HHBS: Hypertension health belief scale.

Changes in blood pressure, medication adherence, self-efficacy, and health beliefs between the two groups over time are shown in Table 2. The repeated-measures ANOVA or GEE results showed significant group-by-time interactions for all outcomes, indicating that the intervention group had significantly different outcomes than the control group over time. The intervention group had significantly lower systolic and diastolic blood pressure, higher medication adherence, higher self-efficacy, higher perceived benefits, perceived barriers, perceived susceptibility, and perceived severity than the control group three and six months after the intervention.

Table 2 Changes in blood pressure, medication adherence, self-efficacy, and health beliefs between the two groups over time, mean ± SD.

Variable	Intervention group (n = 70)			Control group (n = 80)			Group-by-time interaction
	Baseline	3 months	6 months	Baseline	3 months	6 months	P value
Systolic blood pressure (mmHg)	149 ± 14	136 ± 12a	133 ± 11a	150 ± 14	145 ± 13	143 ± 12	< 0.001
Diastolic blood pressure (mmHg)	91 ± 9	83 ± 8a	81 ± 7a	92 ± 9	89 ± 8	88 ± 7	< 0.001
Medication adherence score (MMAS-8)	6.2 ± 1.8	7.4 ± 1.1a	7.6 ± 1.0a	6.1 ± 1.8	6.5 ± 1.7	6.7 ± 1.6	< 0.001
Self-efficacy score (SEMCDS)	68.4 ± 1.7	72.4 ± 1.5a	73.2 ± 1.4a	68.0 ± 1.7	69.5 ± 1.6	70.0 ± 1.5	< 0.001
Perceived benefits score (HHBS)	16.8 ± 2.4	18.2 ± 2.2a	18.5 ± 2.1a	16.7 ± 2.4	17.0 ± 2.3	17.2 ± 2.2	< 0.001
Perceived barriers score (HHBS)	11.2 ± 3.1	9.8 ± 2.9a	9.5 ± 2.8a	11.3 ± 3.1	10.9 ± 3.0	10.7 ± 2.9	< 0.001
Perceived susceptibility score (HHBS)	14.6 ± 2.9	16.0 ± 2.7a	16.3 ± 2.6a	14.5 ± 2.9	15.0 ± 2.8	15.2 ± 2.7	< 0.001
Perceived severity score (HHBS)	15.4 ± 2.7	16.8 ± 2.5a	17.1 ± 2.4a	15.3 ± 2.7	15.8 ± 2.6	16.0 ± 2.5	< 0.001

^aP < 0.05 (significant differences between the intervention and control groups at the same time point).

MMAS-8: Morisky medication adherence scale; SEMCDS: Self-efficacy for managing chronic disease scale; HHBS: Hypertension health belief scale.

DISCUSSION

This study evaluated the effects of health education interventions based on the HBM on patients with hypertension in China from 2021 to 2023. The results showed that the intervention group had significantly lower systolic and diastolic blood pressure, higher medication adherence, higher self-efficacy, higher perceived benefits, lower perceived barriers, higher perceived susceptibility, and higher perceived severity than the control group three and six months after the intervention.

The findings of this study are consistent with those of previous studies that have applied the HBM to design and evaluate health education interventions for patients with hypertension in different settings and populations[19-25]. Health education interventions based on the HBM can improve blood pressure control and health beliefs of patients with hypertension by enhancing their knowledge, attitudes, and behaviors related to hypertension prevention and management. The HBM constructs can explain how patients with hypertension perceive the risk and severity of hypertension and its complications, weigh the benefits and barriers of taking antihypertensive medication and modifying their lifestyle, gain confidence and motivation to perform self-management behaviors, and receive cues and support from healthcare providers and other sources[26,27]. Health education interventions based on the HBM can address these constructs by providing tailored and comprehensive information, feedback, guidance, support, and reinforcement for patients[28-30].

The strengths of this study include the use of a randomized controlled trial design, multiple and diverse modes of delivery of health education interventions based on the HBM, and standardized and validated instruments to measure outcomes. The limitations of this study include the relatively small sample size, short duration of follow-up, lack of blinding of the participants and intervention providers, and the potential influence of confounding factors, such as co-morbidities, socio-economic status, and health service utilization.

The implications of this study are as follows: (1) Health education interventions based on the HBM should be implemented in clinical practice and community settings to prevent and manage hypertension; (2) health education interventions based on the HBM should use multiple and diverse modes of delivery to enhance their effectiveness and accessibility; (3) health education interventions based on the HBM should be evaluated using rigorous methods and long-term follow-up to assess their impact and sustainability; and (4) health education interventions based on the HBM should be tailored to the specific needs and preferences of patients with hypertension in different contexts and cultures.

CONCLUSION

This study demonstrated that health education interventions based on the HBM effectively improved blood pressure control and health beliefs of patients with hypertension in China from 2021 to 2023. This study suggests that health education interventions based on the HBM should be widely adopted and further evaluated for the prevention and management of hypertension.