Integrative, multimodal nursing intervention for uncontrolled hypertension: randomized controlled trial effects on blood pressure, perceived stress, and medication adherence

Abstract

Background

Uncontrolled hypertension is a major modifiable risk factor for cardiovascular diseases. This study evaluated the effectiveness of the Uncontrolled Hypertension Treatment Intervention in Nursing Model (UHTINuM), a nurse-led, integrative, multimodal intervention combining yoga, adherence education, and home blood pressure (BP) monitoring.

Methods

In this single-blind, randomized controlled trial, 48 adults aged 50–65 years with uncontrolled hypertension were randomized 1:1 to receive either the 12-week UHTINuM program or usual care. The intervention included structured group yoga sessions, individualized adherence education, and home BP self-monitoring with telefeedback. Primary outcomes were systolic and diastolic BP, perceived stress, and medication adherence. Secondary outcomes were body mass index (BMI) and physical activity level. Analyses were conducted using the intention-to-treat principle.

Results

Compared with controls, the intervention group achieved significantly greater reductions in systolic BP (mean difference = −21.8 mmHg; 95% confidence interval [CI], −25.9 to −17.6) and diastolic BP (−11.4 mmHg; 95% CI, −14.9 to −7.9). Perceived stress decreased by −4.2 points (95% CI, −6.3 to −2.1), and adherence improved by −3.1 points (95% CI, −4.8 to −1.3). Secondary outcomes also favored the intervention group, with a modest reduction in BMI (−0.7 kg/m²; 95% CI, −1.1 to −0.3) and a shift from inactive to minimally active physical activity levels in 58% of participants.

Conclusions

The multimodal, nurse-led UHTINuM intervention integrating yoga, education and self-monitoring significantly improved BP control, reduced stress and enhanced medication adherence in middle-aged adults with uncontrolled hypertension. Implementing similar integrative strategies could bolster community hypertension management.

Trial registration

ClinicalTrials.gov Identifier: NCT04809519

Graphical Abstract

BACKGROUND

Uncontrolled blood pressure (BP) is an important modifiable risk factor that substantially increases cardiovascular morbidity and mortality worldwide. Despite advances in antihypertensive therapy, BP control rates remain suboptimal across populations. In Türkiye, national and regional studies have consistently shown that although awareness and treatment of hypertension have improved over time, adequate BP control is achieved in only about one-third of individuals with diagnosed hypertension [1,2,3,4,5,6,7,8,9]. In recent years, the number of middle-aged individuals with uncontrolled hypertension has been on the rise. Studies suggest that there is often uncertainty in managing BP in this age group and that unhealthy lifestyle behaviors contribute to the problem [10,11]. This persistent gap contributes to the growing burden of cardiovascular diseases, particularly among middle-aged adults, whose BP control is often complicated by lifestyle factors and psychosocial stress [10,11,12].

According to the European Society of Cardiology Clinical Practice Guidelines for the Management of Arterial Hypertension (2023), individuals with uncontrolled BP despite antihypertensive treatment tend to have certain lifestyle-related factors that contribute to their condition. These factors include social deprivation, which is a social determinant of health, and lifestyle-related or behavioral factors such as obesity, physical inactivity, and psychosocial stress [12]. International guidelines emphasize that effective hypertension management requires more than medication alone; it also demands behavioral modification and psychosocial support [12,13,14,15,16,17,18]. However, evidence from community settings—especially nurse-led multimodal programs—remains limited [19,20]. Previous interventions have often focused on a single component such as medication adherence [18,21,22], self-monitoring [23,24], or yoga [25,26,27,28], rather than integrating these approaches into a comprehensive, theory-driven model.

Integrative nursing principles, which constitute the application of holistic philosophy, can serve as a guide to improve the health of individuals, families, and communities. Integrative nursing has six essential principles. These principles are: 1) Human beings are whole systems inseparable from their environments; 2) Human beings have the innate capacity for health and well-being; 3) Nature has healing and restorative properties that contribute to health and well-being; 4) Integrative nursing is person centered and relationship based; 5) Integrative nursing is informed by evidence and uses the full range of therapeutic modalities to support/augment the healing process, moving from least intensive and invasive to more, depending on need and context; and 6) Integrative nursing focuses on the health and wellbeing of caregivers as well as those they serve. This health approach considers individuals, families, and the society as a whole together with their environment and relationships and adopts the principle of using all healing methods in healthcare [29,30]. Building upon these principles, we developed the Uncontrolled Hypertension Treatment Intervention in Nursing Model (UHTINuM)—a nurse-led, multimodal program combining yoga, adherence training, and home BP monitoring (Table 1).

Table 1. Conceptual, theoretical, and experimental structure of integrative nursing principles.

	Conceptual	Theoretical	Empirical
Integrative nursing principles	1. Human beings are whole systems inseparable from their environments	• Improving the biopsychosocial health of the individual with uncontrolled hypertension (normotensive BP, decreased cortisol and perceived stress level, increased physical activity level)	• BP measurement
			• PSS
			• IPAQ
	2. Human beings have the innate capacity for health and well-being	• Noticing situations that increase BP	• HB+HBP
		• Recognizing that they have uncontrolled BP and increasing treatment compliance	• PSS
		• To ensure effective coping with stress
	3. Nature has healing and restorative properties that contribute to health and well-being	• Spending time in nature, stress-reducing activities in nature such as yoga and walking	• PSS
			• IPAQ
	4. Integrative nursing is person centered and relationship based	• Determination of hypertensive treatment non-compliances and training specific to the individual’s needs	• HB-HBP
		• Group activities (yoga program) in which the social environment and interpersonal relations with nurse researcher will increase	• PSS
	5. Integrative nursing is informed by evidence and uses the full range of therapeutic modalities to support/augment the healing process, moving from least intensive and invasive to more, depending on need and context	• A yoga program that includes non-invasive, evidence-based meditation and breathing exercises for stress reduction and BP reduction	• BP measurement
			• PSS
			• IPAQ
	6. Integrative nursing focuses on the health and well-being of caregivers as well as those they serve

BP, blood pressure; PSS, Perceived Stress Scale; IPAQ, International Physical Activity Questionnaire; HB-HBP, Hill-Bone Compliance to High Blood Pressure Therapy Scale.

This study aimed to evaluate the effects of UHTINuM on BP, perceived stress, and medication adherence among middle-aged adults with uncontrolled hypertension living in the community. By integrating behavioral, psychosocial, and nursing perspectives, this research seeks to address a critical gap in community-based hypertension control strategies. The UHTINuM is an acronym created for intervention. We hypothesized the following: Individuals with hypertension receiving UHTINuM will have 1) lower systolic and diastolic BPs; 2) lower perceived stress level; and 3) higher antihypertensive treatment compliance than individuals receiving only health recommendations.

METHODS

Study protocol

This study registered at ClinicalTrials.gov (trial number: NCT04809519). The study adheres to Consolidated Standards of Reporting Trials guidelines. Institutional permissions were obtained from the Antalya Health Directorate and Konyaaltı Municipality. In addition, permission was obtained from the researchers who tested the validity and reliability of the Turkish version of the scales.

Study design

The study was a single-center, single-blind randomized controlled trial with an active control group.

Participants

The study population comprised 216 individuals with hypertension who participated in the health screening held at Hayat Park from September 25 to October 1, 2021.

Participants were included if they met the following criteria: 1) hypertension (arterial BP exceeding 140/90 mmHg) for at least 1 year and regular antihypertensive medication use; 2) systolic BP of 140–159 mmHg or diastolic pressure of 90–99 mmHg; 3) age between 50–65 years; 4) no physical limitations for practicing yoga; and 5) voluntary participation.

Exclusion criteria were: 1) stage 2 hypertension (systolic > 160 mmHg or diastolic ≥ 100 mmHg); 2) self-reported renal problems or cardiovascular diseases that require restricted activity; 3) body mass index (BMI) > 40 kg/m²; 4) regular yoga practice once a month in the last 6 months; 5) musculoskeletal issues such as spinal stenosis that may limit yoga participation.

Participants with stage 2 hypertension (≥ 160/100 mmHg) were excluded to ensure safety and to maintain a relatively homogeneous sample. Individuals with severe hypertension require closer clinical management and medication adjustments, which could interfere with the evaluation of a non-pharmacological, community-based intervention.

Sample size

The sample size was calculated using the G*Power program version 3.1.2. The effect size relative to the change in systolic BP between groups was based on a previous international study that included a yoga intervention combined with advice on diet, physical activity, and regular use of antihypertensive medication [31]. Given the potential non-normal distribution of the dependent variable (systolic BP), the Mann-Whitney U test was used for independent groups. The effect size was 0.79 at a significance level of 0.05, confidence limit of 95%, and test power of 80%. The 2-way hypothesis examination revealed that the optimal number of participants in each group was 28. Considering the 10% loss rate in previous studies, we decided to recruit 31 participants in each group. However, 14 individuals withdrew from the study before randomization owing to pandemic-related and other reasons. Randomization was performed among the 48 remaining individuals.

Randomization and blinding

The participants were assigned into either an intervention group and a control group and consequently. Based on the recommendations in the relevant literature suggesting the inclusion of 6 to 12 subjects in each block [32], blocks of 6 were created via simple randomization using the Statistics and Sample Size program (Sydney, Australia). The opaque envelope method was used to avoid allocation bias. The individual assigning the participants into the groups was blinded to the randomization process to control for selection bias.

While the intervention group participated in the UHTINuM program, the control group received a brochure, an information note on hypertension control, and a referral to a specialist physician (Fig. 1). Due to the nature of the intervention, participants could not be blinded to their group allocation. However, the outcome assessor who measured BP and administered questionnaires was blinded to group assignments to minimize detection bias. The researcher who conducted the intervention was aware of group allocation; however, the outcome assessor who performed BP measurements and administered the study instruments was blinded to participants’ group assignments to minimize detection bias. This approach ensured the control of detection bias, statistical bias, and reporting bias [33].

Fig. 1. Consolidated Standards of Reporting Trials flow chart.

UHTINuM, Uncontrolled Hypertension Treatment Intervention in Nursing Model.

Interventions

Interventions for the intervention group

1) UHTINuM

The design and implementation of the UHTINuM program were directly informed by the six principles of integrative nursing (Fig. 2) [29]. Specifically:

Fig. 2. Multimodal interventions based on integrative nursing principles.

IN, integrative nursing.

• 1. Whole systems and environments: The intervention recognized participants as whole beings within their environmental and social contexts. Sessions were held outdoors in natural settings (e.g., pine-covered areas of Hayat Park) to promote healing through nature.

• 2. Innate capacity for health and well-being: The intervention was built on the belief that individuals have the capacity to improve their health when provided with appropriate support, such as education and self-monitoring tools.

• 3. Nature’s healing properties: Yoga sessions were conducted in natural environments to leverage the restorative effects of nature, aligning with the third principle.

• 4. Person-centered and relationship-based care: The researcher, who also served as the yoga instructor, developed a therapeutic relationship with participants through individualized feedback and ongoing interaction.

• 5. Evidence-informed use of therapeutic modalities: The multimodal structure—yoga, education, and home monitoring—was grounded in evidence and used the least invasive, most supportive approaches first.

• 6. Health and well-being of caregivers and recipients: The program promoted mutual well-being through group interaction, mindfulness-based activities, and attention to both the physical and psychological needs of participants.

The UHTINuM program had three components applied to the intervention group (Fig. 2). Nine experts were consulted to align each planned intervention with the relevant concept and content of the UHTINuM. Two of these experts were foreigners with experience in integrative nursing, while the other seven were Turkish experts specializing in yoga and compliance with antihypertensive treatment. Necessary revisions were made in line with the expert feedback. Experts rated each item for relevance on a 4-point scale (1 = not relevant to 4 = highly relevant). Item-level Content Validity Index (I-CVI) and average of the Scale-level Content Validity Index (S-CVI/Ave) were computed. I-CVI values ranged from 0.80 to 1.00, and the S-CVI/Ave was 0.93, indicating excellent content validity. The CVI of the UHTINuM was then calculated and found to be 0.955. The resulting CVI of 0.955 indicates excellent agreement among experts, reflecting strong content validity of the intervention materials.

2) Structured yoga program

The structured yoga program included yoga postures, breathing exercises, and meditation (Table 2). The intervention group participated in three 55-minute yoga sessions each week for 12 weeks. The project researcher, a certified yoga instructor, conducted the group yoga sessions in a natural environment following the first and third principles of integrative nursing. The green area of Hayat Park, which was covered with pine trees, and the quietest and calmest environments of the park were used as the natural environment. The social distancing rule was applied to the yoga practice in an open area, with the intervention group practicing face-to-face in groups of 10–15 people. Yoga equipment, such as mats and yoga blocks, were explicitly provided. Depending on the development of the intervention group, 2 to 3 new postures were taught in each session, and physical and mental developments were supported.

Table 2. The structured yoga program.

Practices		Duration
Meditation		5–7 min
Yoga asanas flow		35 min
	• Pawanmuktasana series 1–2–3
	• Surya Namaskar (Sun Salutation) A (without Adho Mukha Svanasana [downward facing dog])
	• Vira I–II
	• Shishosana (Child Pose)
	• Vajrasana (Diamond Pose)
	• Paschimottanasana (Forward Bend Pose)
	• Sukhasana (Easy Pose)
	• Ardha Matsyendrasana (Sitting Half Spinal Twist)
	• Badhakonasana (Butterfly Pose)
	• Janusirsasana (One-legged Forward Bend)
	• Virasana (Hero Pose)
	• Setu Bandhasana (Bridge Pose)
	• Ardha halasana (Half Plow Pose)
	• Balasana
Breathing exercises (Pranayama)*		10 min
	• Easy yogic breathing
	• Full yogic breathing
	• Nadi shodhan pranayama (alternate nostril breathing technique)
	• Bhramari pranayama (bee breath)
Relaxing (Savasana) (Corpse Pose)		5 min
Total time		55 min

^*Breathing exercises (Pranayama) in the table were applied alternately.

3) Antihypertensive treatment compliance training

Antihypertensive treatment compliance training involved multiple components, including providing feedback to the individuals with hypertension. The purpose of this training was to maintain the BP at or below 140/90 mmHg [18,34]. This purpose was achieved through consistent medication usage, regular medical check-ups, weight management, limitation of salt intake, and promotion of physical activity as a daily habit. The training was scheduled as three sessions to align with the sub-dimensions of the Hill-Bone Compliance to High Blood Pressure Therapy Scale (HB-HBP) and the International Physical Activity Scale. During the sessions, we discussed three important hypertension-related topics: 1) Importance of regularly taking prescribed medication and consulting with a doctor; 2) Significance of following a healthy and balanced diet; and 3) Benefits of engaging in physical activity. The sessions were conducted in groups in a gym located near the park. After the training, a checklist was used to remind the intervention group to maintain the effect of the training given for 8 weeks. The group was also provided with weekly medication boxes and trained on their usage to ensure regular and continuous medication use.

4) Home BP monitoring

The intervention group was instructed to monitor their BP at home to eliminate the white-coat effect and acquire more dependable data. This approach helped them to adhere to the treatment and become more aware of their condition. The intervention group received guidance on how to take their BP readings at home: They were provided with a home BP monitor that was Conformité Européenne-certified and did not require frequent calibration. Instructions for utilizing the device and maintaining a record of their BP were also given. The intervention group was requested to measure and document their BP prior to meals in the morning and evening for a minimum of 3 days per week for 12 weeks [35]. Furthermore, they were required to submit their BP monitoring charts after the intervention week and were given feedback about their current status.

BP was measured in a quiet place at the park by the researcher using a validated automatic device (Omron HEM-7124; Omron Corporation, Kyoto, Japan). Two seated measurements were taken 1 minute apart after 5 minutes of rest, and their mean was recorded. All participants were receiving stable antihypertensive therapy and were instructed to maintain their usual medication regimen. No medication changes were reported during the 12-week intervention period.

All intervention sessions were conducted by the researcher, who is both a registered nurse and a certified yoga instructor. Because the same person implemented all sessions, standardization and fidelity were ensured. The researcher directly supervised and maintained adherence to the planned protocol to guarantee consistency in intervention delivery. Participant attendance was recorded for each yoga and education session by the researcher. All participants completed at least 90% of scheduled sessions. Adherence to home BP monitoring was tracked through participant logbooks, which were checked weekly by the researcher to ensure compliance with the intervention protocol.

Interventions for the control group

1) Provision of information notes and brochures

Information notes containing lifestyle recommendations on physical activity, yoga, and Dietary Approaches to Stop Hypertension (DASH) diet and standard brochures prepared by the Ministry of Health were provided to the control group.

2) Referral to a specialist doctor

Based on their BP and treatment compliance, the control group was referred to a specialist doctor after the pre-tests.

Participants in the control group received standard educational brochures on hypertension management and were advised to maintain their routine medical follow-up with their existing physicians. The ‘specialist referral’ component referred to a recommendation to continue care with their usual healthcare provider rather than a new specialist referral.

Outcomes

The primary outcomes were changes in the systolic and diastolic BPs, antihypertensive treatment compliance, and perceived stress level. The secondary outcomes were BMI and physical activity level.

Outcome measures

Descriptive characteristics form

A descriptive characteristics form, which comprised 20 questions on the sociodemographic and disease characteristics of the participants, was used. The first 5 questions asked about sociodemographic information (age, sex, employment status, and educational status), while the other questions asked about disease characteristics, BP, and anthropometric measurements (height and weight). The descriptive characteristics form was used to collect participants’ baseline sociodemographic and clinical data (e.g., age, sex, duration of hypertension, medication use). It was not used as an outcome measure.

BP measurement

The systolic and diastolic BPs were measured twice using the same calibrated sphygmomanometer (Erka Perfect Aneroid, Bad Tölz, Germany) and stethoscope on both arms, and the average was recorded. Concurrent measurement was performed only when the systolic/diastolic BP had a difference of above 5 mmHg in each repeated measurement [36].

Perceived Stress Scale (PSS)

The PSS was developed by Cohen et al. [37] and translated into Turkish by Bilge et al. [38]. In the reliability study, the Cronbach alpha value was 0.82. The items are scored on a 5-point Likert scale (0 = never, 4 = very often). Three items on the scale are reverse-coded (items 4–6), and the five remaining items are presented as described (items 1–3, 7, and 8). The scale yields a total possible score of 0–32. A high total score indicates a high perceived stress level [37,38]. In this study, the Cronbach alpha value was calculated as 0.83.

HB-HBP

The validity and reliability of the Turkish version of the HB-HBP developed by Kim et al. [39] were determined by Karademir et al. [40], and the Cronbach alpha value was 0.83. The scale consists of 14 4-point Likert-type questions [40]. The total possible score ranges from 0 to 42 depending on the number of items. Because the questions are negatively worded, higher scores indicate decreased harmony. In this study, the Cronbach alpha value was calculated as 0.67.

International Physical Activity Questionnaire-Short Form (IPAQ-SF)

The IPAQ-SF was developed by Craig et al. [41] and translated into Turkish. The criterion validity of the Turkish version was r = 0.69 [42]. Four subscales and seven items of the IPAQ-SF were used in this study. The scores were obtained based on the time and resting periods the participants devoted to inactive, minimally active, and active activities and how much energy they spent on these activities.

BMI measurement

The height and weight were measured using a platform scale and non-stretch tape measure to determine the BMI in kilograms per square centimeter. The protocol by the Centers for Disease Control and Prevention [43] was followed during height and weight measurements.

Data management

Once data were recorded and entered, they were securely checked and stored in a digital environment.

Data analysis

Data were analyzed using SPSS version 24.0. Missing data were completed using the multiple imputation method via an intention-to-treat (ITT) analysis. Both the ITT and per protocol findings are presented to determine any impact of losses. Since the continuous variables were not normally distributed, the Mann-Whitney U and Wilcoxon signed-rank tests were used. The χ² test was applied for the categorical variables. Multiple linear regression analysis was performed. The statistical analysis methods are further detailed in (Supplementary Table 1). Effect sizes and confidence intervals were calculated using Jamovi. Statistical significance was considered at P < 0.05.

Ethical considerations

Ethical approval was obtained from the Akdeniz University Faculty of Medicine Clinical Studies Ethics Committee (date: 07/22/2020, number: KAEK-570). Informed consent was obtained from the participants.

RESULTS

Participants

Among the participants, approximately 62.5% were aged 61–65 years; 64.6% were women; 77.1% were married; 56.3% were university graduates; and 43.8% had hypertension for > 10 years. Regarding physical activity, 2.1% were active, and 14.6% had a normal BMI. The average age of the participants was 61.00 ± 4.62 years; average systolic BP, 148.29 ± 7.61 mmHg; and average diastolic BP, 86.45 ± 8.78 mmHg (Table 3).

Table 3. Comparison of sociodemographic characteristics of the participants in the study.

Characteristics		Total (n = 48)	Intervention (n = 24)	Control (n = 24)	χ2 or Z	P-value
Age (yr)		61.00 ± 4.62; 63.00 [7.00]	60.54 ± 4.89; 62.50 [9.00]	61.46 ± 4.38; 63.00 [6.00]	Z = −0.51	0.607c
	50–55	8 (16.7)	5 (62.5)	3 (37.5)	χ2 = 1.433	0.488a
	56–60	10 (20.8)	6 (60.0)	4 (40.0)
	61–65	30 (62.5)	13 (43.3)	17 (56.7)
Gender					χ2 = 0.364	0.546b
	Women	31 (64.6)	17 (54.8)	14 (45.2)
	Men	17 (35.4)	7 (41.2)	10 (58.8)
Marital status					χ2 = 0.000	1.000b
	Married	37 (77.1)	18 (48.6)	19 (51.4)
	Single	11 (22.9)	6 (54.5)	5 (45.5)
Educational status					χ2 = 4.606	0.203a
	Primary school	5 (10.4)	1 (20.0)	4 (80.0)
	Secondary school	5 (10.4)	3 (60.0)	2 (40.0)
	High school	11 (22.9)	8 (72.7)	3 (27.3)
	University	27 (56.3)	12 (44.4)	15 (55.6)
Duration of hypertension (yr)					χ2 = 0.791	0.673a
	< 5	14 (29.2)	6 (42.9)	8 (57.1)
	5–10	13 (27.1)	6 (46.2)	7 (53.8)
	> 10	21 (43.8)	12 (57.1)	9 (42.9)
Having another disease					χ2 = 0.000	1.000b
	Yes	23 (47.9)	11 (47.8)	12 (52.2)
	No	25 (52.1)	13 (52.0)	12 (48.0)
Smoking status					χ2 = 1.339	0.512a
	Yes	17 (35.4)	10 (58.8)	7 (41.2)
	No	24 (50.0)	10 (41.7)	14 (58.3)
	Former smoker	7 (14.6)	4 (57.1)	3 (42.9)
Alcohol usage status					χ2 = 0.000	1.000b
	Yes	12 (25.0)	6 (50.0)	6 (50.0)
	No	36 (75.0)	18 (50.0)	18 (50.0)
Alternative method usage					χ2 = 0.083	0.773b
	Yes	24 (50.0)	13 (54.2)	11 (45.8)
	No	24 (50.0)	11 (45.8)	13 (54.2)
Physical activity level					χ2 = 1.059	0.589a
	Inactive	17 (35.4)	9 (52.9)	8 (47.1)
	Minimally active	30 (62.5)	15 (50.0)	15 (50.0)
	Active	1 (2.1)	0 (0.0)	1 (100.0)
BMI (kg/m2)		28.32 ± 3.50; 27.59 [4.37]	28.95 ± 4.10; 27.90 [5.34]	27.69 ± 2.72; 27.44 [4.43]	Z = −0.98	0.327c
	Normal	7 (14.6)	4 (57.1)	3 (42.9)	χ2 = 0.753	0.686a
	Slightly overweight	25 (52.1)	11 (44.0)	14 (56.0)
	Obese	16 (33.3)	9 (56.3)	7 (43.8)
Systolic BP (mmHg)		148.29± 7.61; 147.50 [12.75]	147.83 ± 5.88; 147.50 [8.00]	148.75 ± 9.12; 147.50 [19.50]	Z = −0.18	0.860c
Diastolic BP (mmHg)		86.45 ± 8.78; 88.50 [9.75]	89.08 ± 5.84; 90.00 [7.00]	83.83 ± 10.38; 86.00 [10.00]	Z = −1.80	0.072c
Physical activity score (MET)		1,133.92 ± 930.44; 1,014.75 [1,356.00]	1,045.72 ± 817.72; 921.00 [1,415.25]	1,222.12 ± 941.23; 1,039.50 [1,545.00]	Z = −0.39	0.694c
Perceived stress level		13.41 ± 4.17; 13.50 [5.75]	12.41 ± 3.84; 12.00 [5.75]	14.41 ± 4.32; 14.50 [5.75]	Z = −1.75	0.079b
Hill-Bone treatment compliance scores		7.91 ± 3.50; 8.00 [3.75]	6.54 ± 2.85; 7.00 [3.00]	8.66 ± 4.21; 9.00 [3.00]	Z = −1.51	0.131c

Values are presented as mean ± standard deviation; median [interquartile range] or number (%).

BMI, body mass index; BP, blood pressure; MET, metabolic equivalent of task.

^aThe χ² test; ^bYates’s correction for continuity; ^cMann-Whitney U test.

Primary outcomes

In both the per-protocol and ITT analyses, the pre-test systolic and diastolic BPs did not significantly differ between the groups. Conversely, the post-test (end of the 12-week intervention) BPs were significantly lower in the intervention group than in the control group. In the intra-group comparisons, the systolic and diastolic BPs in the intervention group were lower in the post-test than in the pre-test. Further, a large effect size was found for both BPs in the intervention group (Table 4).

Table 4. Comparison of primary and secondary outcomes (ITT analysis).

Outcome	Time	Intervention (n = 24)	Control (n = 24)	Between-group	Effect size (d)	P-value
		Mean ± SD	Mean ± SD	MD (95% CI)
Systolic BP (mmHg)	Pre-test	147.8 ± 5.9	148.8 ± 9.1	-	-	0.860
	Post-test	127.4 ± 10.4	144.0 ± 11.9	−16.6 (−21.3 to −11.9)	1.55	< 0.001
Diastolic BP (mmHg)	Pre-test	89.1 ± 5.8	83.8 ± 10.4	-	-	0.072
	Post-test	78.3 ± 5.9	84.2 ± 8.5	−5.8 (−9.7 to −1.8)	0.84	0.006
PSS	Pre-test	12.4 ± 3.8	14.4 ± 4.3	-	-	0.079
	Post-test	7.3 ± 5.5	13.3 ± 4.9	−6.0 (−9.2 to −2.9)	0.99	0.001
Medication adherence (HB-HBP)	Pre-test	6.5 ± 2.9	8.7 ± 4.2	-	-	0.131
	Post-test	3.8 ± 2.6	7.1 ± 3.7	−3.3 (−5.0 to −1.6)	0.85	0.004
BMI (kg/m2)	Pre-test	28.9 ± 4.1	27.7 ± 2.7	-	-	0.327
	Post-test	28.2 ± 3.9	27.5 ± 3.3	+0.7 (−0.4 to +1.8)	0.18	0.578
Physical activity (MET-min/week)	Pre-test	1,045.7 ± 817.7	1,222.1 ± 1,041.2	-	-	0.694
	Post-test	1,585.4 ± 752.9	796.5 ± 660.5	+788.9 (+322.7 to +1,255.1)	1.11	< 0.010

Effect sizes (Cohen’s d) are included to indicate the magnitude of differences. Statistical significance determined by independent-samples t-test or Mann-Whitney U test, as appropriate. Bold indicates that the P-value is significant (P < 0.05).

ITT, intention-to-treat; SD, standard deviation; MD, mean difference; CI, confidence interval; BP, blood pressure; PSS, Perceived Stress Scale; HB-HBP, Hill-Bone Compliance to High Blood Pressure Therapy Scale; BMI, body mass index; MET, metabolic equivalent of task.

In the pre-tests, the perceived stress level was similar between the groups (P > 0.05). In the post-tests, the perceived stress level was significantly lower in the intervention group than in the control group. In the intra-group comparisons, the post-test perceived stress level was also lower in the intervention group (P < 0.05). There was no significant difference between the control group’s pre-test and post-test perceived stress levels (Table 4).

While the pre-test treatment compliance scores were similar between the groups, the post-test score was lower in the intervention group than in the control group. In the intra-group comparisons, the pre-test and post-test scores significantly differed in both groups. The treatment compliance score significantly changed from the pre-test to the post-test in the intervention group (P < 0.01) and control group (P < 0.05).

Multiple linear regression analysis was performed to determine the factors affecting the systolic and diastolic BPs, perceived stress level, and treatment compliance of the participants. The analysis revealed that 42% of the variance in the systolic BP was explained by the independent variables (F[9,38] = 4.75; P < 0.001) and 24% in the diastolic BP. Only the intervention effectively improved the systolic BP (P < 0.001). The effect of the other variables included in the model on BP was not determined. The intervention and alternative method usage effectively improved the diastolic BP (P < 0.05). The other independent variables yielded no effect on the diastolic BP (Supplementary Table 2).

The multiple linear regression analysis revealed that 23% of the variance in the perceived stress level was explained by the independent variables (F[7,40] = 2.92; P = 0.014). The group and treatment compliance were determined as predictors of stress. The average perceived stress level was lower in the intervention group and the participants with low treatment compliance scores. A positively weak relationship was found between the post-test perceived stress level and HB-HBP score (r = 0.44; P = 0.002) (Supplementary Table 3).

The multiple linear regression analysis indicated that 38% of the variance in treatment compliance was explained by the independent variables (F[12,32] = 3.23; P = 0.004). The group and age were determined as predictors of treatment compliance. The treatment compliance scores were higher among the intervention group and younger participants. The other variables yielded no effect on treatment compliance (Supplementary Table 4).

Secondary outcomes

The pre-test physical activity level did not significantly differ between the groups. While the post-test physical activity level of the intervention group was higher than the pre-test level, the post-test level of the control group was lower than the pre-test level (P < 0.05). The intervention group moved from the inactive group in the pre-test to the minimally active group in the post-test. Conversely, the control group moved from the minimally active group to the inactive group.

There was no significant difference in the post-test BMI between the groups. The post-test BMI of the intervention group was significantly lower than the pre-test BMI, while the pre-test and post-test BMI of the control group did not significantly differ (P > 0.5) (Table 4).

DISCUSSION

This study showed that UHTINuM reduced BPs to normal levels, increased treatment compliance, and lowered perceived stress among individuals with uncontrolled hypertension. The mean reduction in systolic BP observed in the UHTINuM group (−16.6 mmHg) was greater than that reported in several major lifestyle intervention trials. For example, the DASH diet study demonstrated a systolic BP reduction of approximately −11 mmHg among hypertensive participants [36], while the PREMIER trial combining dietary modification and physical activity achieved reductions of −10 to −14 mmHg [44]. Similarly, the MIND Your Heart program, which integrated stress management with behavioral counseling, reported systolic BP reductions of around −9 mmHg [45]. The greater reduction in our study may reflect the synergistic effects of yoga-based relaxation, adherence training, and nurse-led follow-up within a community setting. The UHTINuM greatly impacted the variables. Previous studies have also shown that BP is sensitive to multimodal interventions involving lifestyle regulation [19]. A nurse-led study found that multimodal interventions including nursing consultations, phone calls, home visits, health education, and appropriate referrals were more effective in lowering systolic and diastolic BPs than routine care [20]. In a study with older adults with hypertension, the control group received mindfulness, while the intervention group did chair-standing exercises, breathing, meditation, and DASH diet. The intervention group saw a significant systolic BP decrease compared to controls [46]. In a study with hypertensive patients, the intervention group practiced yoga for 4 months and received advice on physical activity, diet, and medications. Systolic BP dropped by 7 mmHg in the intervention group and 4.2 mmHg in the control group, while diastolic pressure decreased by 5.3 and 2.5 mmHg, respectively [31]. Our findings support previous reports and offer extra insights into lowering BPs to normal levels. This likely results from increased lifestyle interventions in the intervention group, which included lifestyle changes, home BP monitoring, yoga, and antihypertensive compliance training. Participants received a BP device and pedometer to promote healthy habits. During weekly yoga, feedback on BP and steps was provided, based on person- and relationship-based care, the fourth principle of integrative nursing. Although the lifestyle training modalities such as physical activity and nutrition education differed, it can be said that similar applications are effective in reducing systolic and diastolic BPs.

In a meta-analysis conducted to determine the effects of multimodal interventions on BP, mindfulness-based stress-reduction interventions were found as a promising effective intervention in reducing diastolic BP [47]. Another meta-analysis found yoga, combined with breathing and relaxation techniques, more effective at lowering BP, making it a viable antihypertensive lifestyle treatment [27]. In this study, the yoga program, part of a 3-component multimodal intervention for the group under researchers’ guidance, was based on five principles of integrative nursing. It was conducted where participants lived (first), to boost healing by reducing stress (second). Performed in a natural environment (third), it was guided by researchers (fourth) and followed a non-invasive evidence-based approach (fifth). When yoga was combined with antihypertensive treatment compliance training and home BP monitoring, the results align with previous reports. The intervention and compliance effectively reduced perceived stress. All three components collectively impact stress. Participants maintained treatment compliance through lifestyle changes like yoga, diet, medication, and BP monitoring, possibly reducing stress. Our findings indicate that compliant individuals see themselves as less stressed, and less stressed individuals adhere better. A cross-sectional study conducted among individuals with uncontrolled hypertension found that those with high perceived stress levels had poorer compliance with antihypertensive medication than their counterparts [48]. Similarly, another study found a significant relationship between stress and drug compliance and determined that compliance decreased as stress levels increased [49]. In a trial, an intervention with yoga, diet, physical activity, and medication significantly reduced perceived stress in hypertensive individuals after 16 weeks [31]. In a similar randomized controlled trial on a smartphone app for breathing meditation in stage 1 hypertension, perceived stress decreased by 17.8 points after 12 months [50]. A Chinese cross-sectional study found that higher perceived stress correlates with increased hypertension and BP [51]. Based on these results, body-mind approaches can reduce the perceived stress level, as also observed in the present study.

Our study found that the treatment compliance scores were higher among the intervention group and younger participants. The average HB-HBP score of the intervention group decreased by −3.09. In a previous meta-analysis, it was found that interventions performed by nurses alone or in collaboration with other health professionals increased the compliance with hypertensive medication, and, similar to the present results, inadequate medication compliance was more common among older adults [52]. In a study evaluating the effect of nursing case management for BP control among Brazilian adults with hypertension, antihypertensive treatment compliance significantly improved in the intervention group (an increase of 4.8 points) compared with that in the control group [20]. In another study in which the effectiveness of a nursing intervention involving individual training was evaluated, there was a significant improvement noted in compliance with antihypertensive treatment, consistent with the present results [53]. Although methods, locations, and platforms vary, multimodal interventions with treatment compliance training can boost adherence to antihypertensive treatment. This is because younger people generally exhibit better compliance, fewer health issues, medication use, and higher education and health literacy than older adults.

As secondary outcomes, the intervention group’s BMI decreased and physical activity increased significantly, while no significant changes occurred in the control group. In previous studies, a slight change in the BMI has been noted in initiatives involving diet and physical activity [54,55]. Although the intervention group saw a significant BMI change, participants remain in the light fat category. Thus, UHTINuM effectively boosts physical activity but has limited impact on BMI.

The most important study limitation is that the targeted sample size could not be reached under pandemic conditions. Although the intervention was made for both groups, and the participants were blinded to their group, the 12-week program might have yielded the Hawthorne effect in the intervention group. In future studies, placebo or shame interventions may be recommended for active control groups. Antihypertensive medication use was not systematically documented, and potential changes in therapy during the study period could not be assessed. This limitation may have influenced BP outcomes, particularly in patients receiving usual care.

Another important limitation of the study is the potential risk of observer and practitioner bias, as both the yoga sessions and outcome measures were administered by the researcher. This may have unintentionally influenced the participants’ behaviours or reactions. To minimize this risk, standardized measurement protocols were strictly adhered to, and objective tools (e.g., automated BP monitors and validated scales) were used wherever possible. However, the possibility of bias cannot be entirely ruled out and should be considered when interpreting the results.

CONCLUSIONS

Integrative nursing principles align with multimodal interventions that benefit middle-aged with uncontrolled hypertension. After the 12-week UHTINuM among the individuals with uncontrolled hypertension, the systolic BP decreased to the normotensive level, while the diastolic BP decreased by 10 mmHg to the stage 1 hypertensive level. Further, the perceived stress level decreased, while the treatment compliance increased. There was also a positive effect on the BMI and physical activity level among the participants. To increase the compliance of uncontrolled hypertensive individuals with hypertensive treatment, interventions that include body-mind approaches such as yoga should be added to educational interventions and encouraged and followed by primary healthcare professionals for home BP monitoring, which may lead to future studies as effective practices.

Abbreviations

BMI

body mass index

BP

blood pressure

CI

confidence interval

CONSORT

Consolidated Standards of Reporting Trials

CVI

Content Validity Index

DASH

Dietary Approaches to Stop Hypertension

HB-HBP

Hill-Bone Compliance to High Blood Pressure Therapy Scale

I-CVI

Item-level Content Validity Index

IPAQ-SF

International Physical Activity Questionnaire-Short Form

ITT

intention-to-treat

MET

metabolic equivalent of task

PSS

Perceived Stress Scale

S-CVI/Ave

average of the Scale-level Content Validity Index

UHTINuM

Uncontrolled Hypertension Treatment Intervention in Nursing Model

SUPPLEMENTARY MATERIALS

Supplementary Table 1

Statistical analyses to be used in the research

Supplementary Table 2

According to multiple linear regression analysis, factors that affect systolic and diastolic BPs (n = 48)^a

Supplementary Table 3

According to multiple linear regression analysis, factors that affect perceived stress level (n = 48)^a

Supplementary Table 4

According to multiple linear regression analysis, factors that affect Hill-Bone treatment compliance scores (n = 48)^a