Cardiovascular disease risk management in primary care in Central Vietnam

Vietnam, as a lower middle-income country undergoing rapid urbanization and economic development with an aging population, faces an escalating burden of cardiovascular diseases (CVDs). Over the recent decades, the prevalence of CVDs has surged, with CVDs accounting for 33% of all fatalities in 2012, slightly decreasing to 31% in 2016. Stroke emerged as the leading cause of death among CVDs. Hypertension, a significant preventable risk factor for CVDs, has seen a rapid surge in prevalence in Vietnam, increasing from 16.9% in 2001-2002 to 30.3% in 2018. However, the awareness of hypertension remains low, posing challenges in detection, diagnosis, and management.
Studies reveal less than half of the hypertensive individuals are aware of their condition, with only a fraction receiving proper treatment, and a mere 10.7% achieving targeted blood pressure (BP) control. Despite the mounting impact of CVDs, Central Vietnam lacks comprehensive data on CVD risk and hypertension management, underscoring the urgent need for exploration and solutions. To address these issues, the present dissertation pursued six objectives across two studies.

The first study, a cross-sectional investigation, aimed to estimate the 10-year CVD risk and investigate the prevalence, awareness, treatment, and control of hypertension in Central Vietnam. With a multi-staged sampling method, 969 participants aged 40-69 were selected. Data encompassing cardiovascular risk factors were gathered through standardized questionnaires and interviews, including anthropometric and BP measurements, along with blood tests. The CVD risk was calculated using the World Health Organization/International Society of Hypertension (WHO/ISH) risk prediction charts. Multivariate logistic regression analysis was performed to examine the association between the prevalence, awareness, treatment and control of hypertension and the associated risk factors.

According to the WHO/ISH charts, the prevalence of moderate and high cardiovascular risks was equal at 5.1%. However, when applying a BP threshold of more than 160/100 mmHg, the proportion of moderate risk decreased to 2.3%, while the proportion of high risk markedly increased to 12.8%. These proportions were higher in men (18.3%) than in women (8.5%), with an increase observed with age.

The prevalence of hypertension stood at 44.8%, being higher in men compared to women (51.3% versus 39.7%). Among the hypertensive participants, 67.3% were aware of
their hypertension, with a higher proportion among women than men (74.5% versus 60.1%). Treatment rates were 33.2%, with again a higher proportion among women than men (37.5% versus 28.9%), and only 12.2% of the hypertensive participants achieved controlled hypertension, with a similar trend favoring women over men (16.7% versus 7.8%). Factors such as age group, gender, residence, body mass index, and diabetes emerged as independent risk factors for hypertension.

The second study, a baseline one, was conducted in three provinces involving 761 hypertensive patients from community health centers. Data on socio-demographic factors, medical history, lifestyle, clinical indicators, medication adherence, hypertension knowledge, as well as patient beliefs and perceptions about hypertension were collected using a standardized questionnaire. Medication adherence was assessed using the 5-item version of the Medication Adherence Report Scale, while knowledge of hypertension and beliefs about medicine were evaluated using the Hypertension Knowledge Level Scale and Belief about Medicine Questionnaire respectively. The CVD risk was estimated using the 2019 WHO CVD risk charts for Southeast Asia. Logistic regression analysis was utilized to identify key factors associated with medication adherence and hypertension knowledge.

The findings revealed that the prevalence of low, moderate, and high cardiovascular risks stood at 52.1%, 38.9%, and 9.0% respectively. There was an increase in cardiovascular risk with age, reaching 27.6% in the 70-74 age group, with higher prevalence among men than women (17.6% versus 2.4%). Only half of the hypertensive patients adhered to their prescribed medication regimens. The mean hypertension knowledge score was 15.0 out of a total of 22 (standard deviation = 4.6), with only 45.3% demonstrating a high level of knowledge. Medication adherence was suboptimal and influenced by various factors such as age, ethnicity, education, home BP monitoring, diet, and beliefs. Similarly, hypertension knowledge was lacking, with educational level, ethnicity, and beliefs affecting the knowledge levels.

Overall, these findings underscored the significant burden of CVD risk and hypertension in Central Vietnam, emphasizing the need for targeted interventions and increased awareness to effectively address this public health challenge. Effective interventions should employ a multifaceted approach to comprehensively tackle the diverse elements contributing to the problem.

An interventional study was designed with control groups and pre-post tests conducted over the course of 6 months in Thua Thien-Hue Province. In the intervention
group, three key interventions were implemented. Participants received a digital home BP monitor with training in its usage, an educational booklet on hypertension management, and group education sessions at each community health center. A reminder system sent text messages twice a week via telephone. Primary outcomes included the difference in systolic BP change between intervention and control groups, while secondary outcomes assessed changes in diastolic BP, medication adherence score, and CVD risk score. Paired-sample ttest and the analysis of covariance (ANCOVA) were used to assess changes in these CVD parameters.

Over the span of 6 months, the intervention group showed a greater decrease in mean systolic and diastolic BP, with reductions of 8.2 mmHg and 4.1 mmHg respectively, as compared to 4.1 mmHg and 2.6 mmHg in the control group. Additionally, the mean medication adherence score in the intervention group increased by 2.5 points compared to 0.9 points in the control group. At the same time, the mean CVD risk score decreased by 2.5 percent in the intervention group as opposed to a 1.7 percent decrease in the control group.

In conclusion, the combination of self-measured BP monitoring, supplemented with patient education, and a reminder system led to significantly improved medication adherence, lowered BP, and reduced CVD risk levels among hypertensive patients in primary care in Central Vietnam. These findings underscored the potential effectiveness of selfmeasured BP monitoring when combined with additional support in enhancing hypertension control and management strategies within primary care settings.