The Correlation Between Quality of Life (QOL) and Medication Adherence to Antihypertensive Medications Among Middle-aged Filipino Adults

Introduction

Hypertension (HTN) is a serious public health issue across the world as it is a major risk factor for heart failure, myocardial infarction, cerebrovascular disease and renal failure. In an article from a media outlet in 2020, a study shows that HTN-related fatalities and disease among Filipino adults have considerably grown over the last three decades and are still projected to increase doubly in the year 2050; with HTN death rates rising from 11% in 1990 to 21% in 2017, and HTN-related disease increasing from 4% to 11%.[1] Hence, controlling HTN and preventing related morbidity and death should be achieved.

A major factor in HTN control is medication adherence, defined by the WHO as the extent to which patients follow prescribed treatments. Non-adherence—including delays, omissions, or early discontinuation—leads to poor blood pressure control and higher complication rates. Locally, the Philippine Heart Association reported a 66% adherence rate in 2007, considered suboptimal.

Various factors influence non-adherence, including socioeconomic status, comorbid conditions and healthcare access. The study would be helpful in understanding how the different domains (physical, psychological, social and environmental) of quality of life (QOL) contribute to medication adherence, which plays an effective role in patient care and treatment, education practices and clinical studies. While most research focuses on elderly patients, this study aims to highlight how QOL impacts treatment adherence in a younger demographic.

Methodology

Study Design

A cross-sectional study conducted in Barangay San Jose, Navotas City involved 92 participants who completed the WHOQOL-BREF and Morisky Medication Adherence Scale (MMAS-8) questionnaires. Scores were analyzed using Pearson’s correlation to assess the relationship between medication adherence and QOL.

Inclusion and Exclusion Criteria

This study included middle-aged Filipino residents (35–65 years old) of Brgy. San Jose, Navotas City, clinically diagnosed with HTN and regularly taking antihypertensive medications. Patients under close monitoring or inpatient care were excluded. The study was conducted in Brgy. San Jose, Navotas City.

Study Procedure

The study involves two main phases: data collection and statistical analysis. Following ethical approval from the UST-FMS Research Ethics Board, 92 middle-aged hypertensive residents from Barangay San Jose, Navotas City were recruited through convenience sampling. Informed consent was obtained before participation. Respondents completed the WHOQOL-BREF and MMAS-8 questionnaires, which assessed their QOL and medication adherence. After data collection, scores were computed and analyzed using Pearson’s correlation coefficient to determine the relationship between the two variables.

Data Collection

A structured survey using WHOQOL-BREF (Filipino) and MMAS-8 was used to assess QOL and antihypertensive medication adherence. The WHOQOL-BREF evaluated four domains: physical, psychological, social and environmental using a 26-item questionnaire, while the MMAS-8 assessed adherence through 8 items. Responses were converted to domain scores and transformed to a 0–100 scale. Assistance and verbal translation were provided for respondents with literacy or language limitations.

Data Analysis

The study used both descriptive and inferential statistics to analyze the relationship between QOL and medication adherence. Descriptive statistics summarized respondent data such as age (mean, standard deviation), gender, education level, economic status and disease severity (mode, frequency, percentage). Pearson’s correlation coefficient was used to determine the strength and direction of correlation between WHOQOL-BREF and MMAS-8 scores. Correlation coefficients (r) were interpreted using standard thresholds and a p-value of <0.05 was considered statistically significant.

Definition of Terms

The following terms are defined for clarity and consistency in the study: (1) Medication adherence refers to the voluntary cooperation of the patient in taking prescribed medications correctly in terms of timing, dosage and frequency. It is quantified using the MMAS-8 with scores ranging from 0 (low adherence) to 8 (high adherence). (2) Middle-aged pertains to individuals aged 35 to 65 years, situated between young adulthood and old age. (3) QOL is assessed using the WHOQOL-BREF questionnaire. It may refer to the overall score or specific domains: Physical, Psychological, Social Relationships and Environment, each rated on a scale from 1 to 5, with higher scores indicating better QOL.

Results

Demographics Profile

The demographic profile of respondents shows that their ages ranged from 36 to 65 years, with a mean age of 53.82 years (SD ± 7.00) and both the median and mode at 54, indicating a concentration around the mid-50s. Most respondents (44.8%) were aged 51–55, followed by 20.8% aged 61–65 and smaller percentages in other age brackets. In terms of sex, the sample was fairly balanced with 51 females (53.1%) and 45 males (46.9%). Regarding educational attainment, over half (53.1%) were high school graduates, while 20.8% had college degrees and 19.8% had completed elementary education. Only a few had some elementary schooling (5.2%) and just 1.0% had no formal education, with no respondents having post-graduate degrees. For monthly income, the majority (53.1%) earned between Php 10,957 and Php 21,913, followed by 20.8% in the Php 21,914–Php 43,828 range. Smaller portions earned below Php 10,956 (19.8%), Php 43,829–Php 76,669 (5.2%) and only 1.0% fell into the highest bracket of Php 76,670–Php 131,483.

Table I:Central measures of the ages of respondents

Table II: Distribution of the ages of respondents

Table III: Sex distribution of respondents

Table IV: Level of education of respondents

Condition Profile

The study population was mainly middle-aged adults recently diagnosed with HTN, with cases peaking between 2010–2019 (40.6%) and 2020–2024 (43.8%), suggesting a rising trend. Prehypertension was the most common BP category (36.5%), followed by stage 1 (30.2%), stage 2 (20.8%) and hypertensive crisis levels (10.4%); 2.1% were unsure of their usual BP. Regarding check-up frequency, 41.7% seldom consulted, 36.5% did so frequently, 19.8% occasionally and 1% always or never.

Losartan (63.54%) and Amlodipine (48.96%) were the most prescribed antihypertensives, often via local government unit (LGU) programs. Other drugs like Metoprolol (5.21%) and various Angiotensin II receptor blocker/Calcium Channel Blockers (ARBs/CCBs) were used by <5%. Combination therapy was common, with 22.92% taking both Losartan and Amlodipine. Three-drug regimens, such as Losartan + Amlodipine + Atorvastatin, or + Metoprolol, were each used by 2.08%.

QOL and Medication Adherence

Table V: Different Pearson’s correlation coefficients between the four domains of QOL and the averaged QOL, and medication adherence

Physical Health and Medication Adherence

The results revealed a moderate positive correlation between physical health and medication adherence with Pearson’s r value of 0.443 and a p-value of 0.01, suggesting that while other factors may also influence physical health, medication adherence plays a meaningful role in improving or maintaining it.

Positive correlation implies that individuals who consistently follow their HTN treatment regimen tend to report better physical function in daily activities.

Patients with better physical health status were also significantly more likely to adhere to their antihypertensive medications.[2] The researchers concluded that physical well-being contributes to the patient’s ability to maintain consistent medication-taking behavior, likely due to the provided relief of symptoms and increased motivation to take care of one's health.

Psychological Factors and Medication Adherence

The correlation between psychosocial factors and antihypertensive medication adherence has been found (r = 0.382, p = 0.01) to have a weak significance. Contentment, optimism, self-esteem, cognitive functioning, spirituality and intensity of negative emotions such as anxiety, sadness or hopelessness were taken into consideration for identifying the psychological state of participants and its potential influence on their medication-taking behavior. These components provide insight into how mental and emotional well-being may support or hinder adherence.

The observed correlation implies that individuals who experience greater emotional stability and strong sense of self-worth are more likely to demonstrate consistent adherence to their antihypertensive medications. Emotional stability characterized by low levels of anxiety, irritability and mood swings help patients stay calm and focused on long-term health goals, making them more resilient in facing the demands of chronic disease management.

Mei, et al. discussed that psychological resilience negatively correlated with depression and that higher resilience levels were associated with better medication adherence, especially when medication burden is low.[3] Similarly, a meta-analysis demonstrated that depressed patients were three times more likely to be non-adherent to medical treatment as compared to non-depressed individuals.[4] This finding underscores the critical impact of mood disorders on chronic disease management including HTN.

Social Relationships and Medication Adherence

The results showed a small and statistically insignificant connection between medication adherence and social relationships (r = 0.163, p = 0.4), indicating that social support has minimal impact on antihypertensive medication adherence. Community responses suggested that the quality of social life may not significantly shape adherence behavior, even if the WHOQOL-BREF included social characteristics such as emotional support and interpersonal relationships. This implies that individuals with stronger social connections are not necessarily more compliant with their medication regimens, and other factors such as personal beliefs, mental health, or access to care may play a more substantial role. These findings align with prior studies. Furthermore, there is no discernible correlation between social support types or levels and blood pressure management or antihypertensive medication adherence.[5] Similarly, a study discovered that while several types of support were present, none of them significantly correlated with adherence.[6] These studies point to the possibility that continuous medication adherence in hypertensive populations may not be fueled by perceived social support alone.

Environmental Factors and Medication Adherence

The results of this study demonstrated a statistically significant, moderate positive correlation between the environmental domain of QOL and adherence to antihypertensive medication (r = 0.446, p = 0.00). Among the four WHOQOL-BREF domains, the environmental domain stood out as the strongest predictor of adherence, as it encompasses external factors directly influencing a patient’s ability to follow treatment—such as access to healthcare, transportation, financial resources, physical safety, work satisfaction and access to health information.

In low-resource settings like Brgy. San Jose, barriers such as high medication costs, limited clinic access and low health literacy are common. Given the statistical significance (p<0.05), the null hypothesis (H₀), which assumes no correlation between adherence and environmental QOL, is rejected. However, due to the study’s cross-sectional design, causality cannot be established.

Each component of the environmental domain contributes uniquely. Perceived neighborhood safety encourages health-seeking behaviors.[7] Job stability also plays a role—shift work or unstable employment was linked to poorer adherence.[8] Financial hardship is a well-established barrier,[9] particularly relevant in this study where most respondents earn below P21,913 monthly. Poor access to healthcare and long wait times further discourage adherence,[10] while inadequate health education contributes to poor understanding of HTN.[11] Even leisure participation impacts well-being and adherence,[12] as well as poor infrastructure and transport issues limit clinic access.[13]

These findings affirm that adherence is not solely a matter of personal discipline but is shaped by broader socioeconomic and structural conditions. For communities like Brgy. San Jose, improving adherence requires multi-sectoral solutions that ensure access to healthcare, safe environments, financial support and community-based health education.

Average QOL

The study found a statistically significant but weak positive correlation between adherence to antihypertensive medication and overall QOL – obtained by averaging the domain scores – (r = 0.336, p<0.001) which suggests that individuals who adhere more closely to their antihypertensive regimen tend to report better perceived QOL scores. While positive correlation is consistent with previous studies on the same topic,[14,15] the degree of association in this population is weaker than expected, which may suggest that other factors may be contributing to these two variables.

A possible explanation for this weak association may be secondary to the multifactorial nature of how individuals perceive their QOL. The questionnaire used in the study, WHOQOL-BREF, aims to assess several domains – physical, psychological, social and environmental – of satisfaction which may not be directly or immediately impacted by medication adherence. Healthcare-wise, social determinants of health such as social policies, income stability, living conditions, access to healthcare and cultural beliefs about illnesses may have a more substantial impact on QOL than adherence alone.[16] Moreover, in settings wherein social and economic challenges persist prevalently as in the urban communities in the Philippines, medication adherence may not be a major determinant of QOL; for instance a compliant patient may still perceive their QOL poorly due to financial stress, poor housing situation, or limited social support.

Secondly, medication adherence is shaped by other factors like health-system-, therapy- and patient-related factors, which may not have been thoroughly assessed in the questionnaire. Locally, a study has found that good healthcare access, strong patient-provider relationships, specialized clinics and insurance were positively associated with adherence while low socioeconomic status, poor health literacy, negative attitudes, irregular medications, use of thiazides and complementary and alternative medicine, and low illness perception were negatively associated; these factors are possible confounding variables in the relationship between adherence and QOL.[17]

Despite these, the finding that a statistically significant relationship exists, although weak, is an evidence of the important interplay between QOL and medication adherence which can be the foci of intervention in managing chronic diseases like HTN.

Conclusion

Among middle-aged adults residing in Brgy. San Jose, Navotas City, better adherence to antihypertensive medication was linked to improvements in QOL, especially in areas related to the environment, physical health and psychological well-being. The strongest relationship was seen in environmental factors like financial security and access to healthcare, while social support appeared to have little impact on adherence. Although the overall relationship was moderate, results point to the importance of addressing both personal habits and external challenges when managing HTN. Efforts to support patients should go beyond medication and include improving health education, accessibility and community support systems.

Recommendations

To build on insights of this study, several steps are suggested for future research on HTN. Researchers should consider using more advanced statistical methods, like regression analysis, to control for factors such as age, sex, income, education and disease history. This would help clarify how adherence truly affects QOL. Improving the sampling method is also important; shifting from convenience sampling to more structured approaches like stratified or cluster sampling could make findings more representative.

Including patients with common coexisting conditions, like diabetes or hypercholesterolemia, would better reflect real-life cases and make results more applicable. Clearer standards for interpreting QOL and adherence scores would also help healthcare workers understand and apply findings more easily. Long-term studies could offer better insight into cause-and-effect relationships, while adding interviews or focus groups would give a deeper look at patient motivations. Lastly, comparing rural and urban settings may reveal how local context shapes adherence. Altogether, these suggestions aim to support better research and more effective community care for Filipinos managing HTN.

Limitations of the Study

Since the study is cross-sectional, it cannot show whether low QOL causes poor medication adherence or the other way around. Both QOL and adherence were based on participants' self-reports, which may not be entirely accurate due to memory lapses or the tendency to give socially acceptable answers. Another key limitation is the lack of statistical adjustments for other factors that could affect adherence like age, existing health conditions, number of medications, or access to healthcare. Lastly, because participants were selected from only one urban, low-income barangay, the findings may not apply to people living in rural areas or those with different economic or social backgrounds.

Conflict of Interest

All authors declare no conflict of interest.