Introduction

Hypertension is a significant risk factor for cognitive impairment and dementia, which is one of the leading causes of death and disability in older adults1, 2. Indeed, hypertension significantly increases the risks of stroke, microbleeds, cerebral white matter lesions, and vascular dementia3. In a cohort study on approximately 430,000 people, it was shown that in individuals aged 60–69 years, per 10 mmHg systolic blood pressure (SBP), the risk of dementia increased by 8%4. According to the World Health Organization, BP control is one of the recommendations for preventing dementia5. A meta-analysis research including six prospective community-based studies with a sample size of 31,090 participants (aged ≥ 55 years) explored that in hypertensive individuals, using antihypertensive medication decreased the risk of dementia and Alzheimer’s disease by 12% and 16%, respectively, compared to those without using antihypertensive medication4, 6. Apparently, treatment of hypertension based on controlling blood pressure plays a critical role in protecting cognition.

Viet Nam, a fast-aging country, is predicted to become an aged country in 20357, with the prevalence of dementia in older adults in the community and hospitals reported at 9.4%8 and 24.3%9, respectively. The prevalence of hypertension among Vietnamese older people was also significantly high (62.1%), resulting in stroke as the leading cause of death and disability10. However, only 12.2% of hypertensive patients had controlled BP11. Therefore, controlling BP in older adults, particularly in those with mild cognitive impairment may prevent them from dementia12. One effective method for BP measurements is using home BP telemonitoring. Compared to office BP measurements, home BP monitoring presents several advantages such as reducing masked uncontrolled hypertension or the white-coat effect13. Moreover, self-measured BP monitoring helps predict cardiovascular outcomes and end-organ damage14. Previous studies also suggested that home BP telemonitoring via the internet or phones promoted antihypertensive medication adjustments faster and enhanced BP control15, 16. However, we lack data on BP telemonitoring in older adults with MCI in Viet Nam.

In this study, we aimed to evaluate the feasibility of home BP telemonitoring in older adults with mild cognitive impairment in an outpatient clinic in Ho Chi Minh City. We evaluated the feasibility of home BP telemonitoring through the rate of recruitment, the rate of participant retention, and patient adherence via the number and types of alerts. The purpose of this study is to examine whether home blood pressure telemonitoring is feasible regarding patient adherence or system problems and to introduce BP telemonitoring as an effective tool for controlling blood pressure.

Methods Study design

A pilot study was conducted at the Geriatric Outpatient Clinic of Ho Chi Minh City University Medical Center, a university hospital located in District 5 in Ho Chi Minh City, Viet Nam. We collected data between November 2021 and May 2022. The study was approved by the Institutional Review Board of the University of Medicine and Pharmacy at Ho Chi Minh City (approval number: 301/HĐĐĐ-ĐHYD).

Figure 1

Patient flow diagram. The study recruited patients aged ≥ 60 years. Eligible participants expressing interest were enrolled. Reasons for exclusion are noted. Participants were allocated to either the Intervention Group or the Control Group. Both groups underwent a 3-month follow-up period with monthly office blood pressure (BP) monitoring using a blood pressure device.

Participants

The inclusion criteria were: (1) aged ≥ 60 years; (2) confirmed diagnosed with primary hypertension based on ESC/ESH Guideline17, identified from the Geriatric Outpatient Clinic, and having uncontrolled blood pressure (SBP ≥ 140 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg at the clinic visit or at home), or newly diagnosed with primary hypertension; (3) mild cognitive impairment, screened by the Montreal Cognitive Assessment (MoCA) test (a total score < 26)18; (4) equipped with wireless internet at home and interested in participating in the intervention and willing to participate in the study.

The exclusion criteria were: (1) diagnosed with dementia according to DSM-519 or (2) severe vision or hearing impairment or (3) the arm circumference > 32 cm or < 22 cm (cuff size available to allow measurements in arms) or (4) not able to take BP measurements at home or (5) atrial fibrillation was excluded due to its impact on oscillometric BP measurement accuracy, which can compromise data reliability in telemonitoring systems (Figure 1).

Procedures

Older patients in the Outpatient Geriatric Clinic during the study period were screened for eligibility. We then explained the study to eligible participants. If they were interested in participating in the study, written informed consent was provided. Given participants’ MCI, caregivers were involved in the consent process to ensure ethical comprehension and voluntary participation, according to local ethical guidelines and international best practices. All patients participating in the study were thoroughly explained about the research process and fully understood the study before signing the consent form in the presence of a family member. All participant information is encrypted and stored in a password-protected computer, with access limited to the researchers only. Due to the nature of the intervention, neither the patients nor the physicians were blinded to the patient’s group assignment. However, outcome assessors and data analysts were blinded. Each participant in the intervention group received a telemonitoring BP device whereas those in the control group received usual care which included taking medications as prescribed and attending routine monthly clinic visits for blood pressure monitoring. All participants were followed up for 3 months.

We also recorded participants’ demographic characteristics including age, sex, educational attainment, living status, income status, comorbidity, polypharmacy, smoking, and physical exercise. Polypharmacy was defined as having ≥ 5 types of medicine concurrently20. Meanwhile, physical exercise was defined when a participant had at least 150 minutes of moderate-intensity aerobic activity per week21.

BP monitoring device

The telemonitoring blood pressure device was developed by the International University - Viet Nam National University Ho Chi Minh City (Model: IUBME_TBP001). It is an automatic BP measuring device with an upper-arm model, including a cuff placed on the upper arm and connected to the monitor by a tube. The monitor is rested on a surface near the arm. Its use is simple with one button START/STOP. This telemonitoring blood pressure device measures and displays systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse, wirelessly transmitting this data to the cloud-based health information system (iHIS) for analysis and storage. Each user has an account on the iHIS database. The iHIS system connects to home monitoring devices via an HL7-based iHIS API, encrypting data with AES (Advanced Encryption Standard) for secure storage in the user's account on the cloud server. The device connects to the Internet via WiFi (10-20 meter range) and its rechargeable Li-ion battery supports approximately 80 measurements per full charge. The monitor features a 0-240 mmHg (±5 mmHg accuracy) blood pressure range, a 40-180 bpm (±3 bpm accuracy) heart rate range, an LCD touchscreen for user selection and WiFi setup, and performs fully automatic measurements on the upper arm. Users can reset or reconnect the device if uploads fail, with phone/message support available. The safety, quality, and compliance of this device as well as the whole telemonitoring BP system, were approved and certified by the official agency of the Ministry of Information and Communications in Viet Nam (approval number: 0006_18/HAKDT/BBKT).

The cloud telemedicine information system was managed by an administrator (a research member), who was able to monitor, store, and process data and permit users to check the patient’s data using a smartphone or a computer. If the patient has abnormal BP (SBP>180 or DBP>110), a warning sign will alarm a geriatrician (a research member). Both this device and the system were used in a controlled study conducted and proven for their reliability in Viet Nam22.

Home blood pressure monitoring training

For the intervention group, two research members (a geriatrician and a technician) trained participants or their caregivers to use the BP telemonitoring device. The intervention group consisted of patients with uncontrolled blood pressure; therefore, the study followed the frequency and duration of blood pressure measurements as recommended by the International Society of Hypertension, and the American Heart Association and American Medical Association guidelines to adjust treatment for patients14, 23. They were instructed to take three BP readings daily and a minimum of three consecutive days per week to ensure adequate clinical decision-making data14. In case we did not receive BP readings for two consecutive weeks, we would contact participants to identify the reasons. Participants and their caregivers were instructed when they contact research staff or what to do when patients had high BP readings (SBP ≥ 180 mmHg or DBP ≥ 110 mmHg).

Alert manager

The alerts were automatically generated when patients had insufficient BP readings (<4 consecutive days for two weeks). We classified the alerts into five categories: (1) patient non-adherence - the patients or their caregivers did not follow the research protocol; (2) patient knowledge - the patients did not know how to use the telemonitoring BP device; (3) device problem - the devices did not work properly; (4) system problem - the patients took sufficient BP readings but the data were not transmitted to the central server; (5) others such as the patients were hospitalized or on vacations.

Outcome measurements

The feasibility of telemonitoring BP included (1) the rate of participant recruitment, (2) the rate of participant retention, and (3) the number and types of alerts from the BP telemonitoring devices.

The rate of participant recruitment was the percentage of participants agreeing to participate in the study. The rate of participant retention was the percentage of participants remaining until the end of the study.

The primary outcome was clinic-measured blood pressure, adjusted for baseline covariates at 3 months. Blood pressure was measured by an investigator using a validated monitor, three times at baseline and each follow-up appointment in a standardized fashion, using the same arm and cuff size each time, in a seated position after at least 5 min rest.

Data analysis

We analyzed data using STATA/MP software version 14.0 (StataCorp, USA). Continuous variables were presented as mean ± standard deviation (SD) or median and interquartile range. Discrete variables were presented as counts and percentages. T-tests were used to compare the means of two groups; Chi-square tests or Fisher exact tests were used to compare proportions, and a p ≤ 0.05 was considered statistical significance.

Table 1

Characteristicsof participants in the study (n = 62)

Age (mean±SD)

72.35 ± 7.76

71.67 ± 7.34

0.725

Age group (years)

60 – 69

14 (45.16)

14 (45.16)

0.753

70 – 79

11 (35.48)

13 (41.94)

≥ 80

6 (19.35)

4 (12.90)

Sex

Women

22 (70.97)

20 (64.52)

0.587

Men

9 (29.03)

11 (35.48)

Educational level

Primary school

14 (45.16)

16 (51.61)

0.871*

Secondary school

9 (29.03)

10 (32.26)

High school

6 (19.35)

4 (12.90)

University/Post-graduate

2 (6.45)

1 (3.23)

Living status

Alone

1 (3.23)

5 (16.13)

0.195*

With family members

30 (96.77)

26 (83.87)

Income status

From employment

0

2 (6.45)

0.671*

From children

15 (48.39)

16 (51.61)

From saving money

11 (35.48)

9 (29.03)

From pension

5 (16.13)

4 (12.90)

Comorbidities

Stroke

5 (16.13)

6 (19.35)

0.740

Ischemic heart disease

10 (32.26)

11 (35.48)

0.788

Heart failure

2 (6.45)

7 (22.58)