|Year : 2022 | Volume
| Issue : 2 | Page : 71-75
Prevalence and predictors of medication nonadherence among hypertensive patients
Deepak Sharma1, Naveen Krishan Goel1, Sarabmeet Singh Lehl2, Dinesh Kumar Walia1, Sonia Puri1, Kritee Shukla1, Shreyas Mishra1
1 Department of Community Medicine, Government Medical College and Hospital, Chandigarh, India
2 Department of General Medicine, Government Medical College and Hospital, Chandigarh, India
|Date of Submission||12-Feb-2022|
|Date of Decision||29-Mar-2022|
|Date of Acceptance||26-Apr-2022|
|Date of Web Publication||22-Jul-2022|
Dr. Deepak Sharma
Department of Community Medicine, Government Medical College and Hospital, Chandigarh
Source of Support: None, Conflict of Interest: None
Introduction: Hypertension is a chronic disease that needs to be treated adequately. Nonadherence to antihypertensive medicines can lead to coronary heart disease and stroke complications. The present study assessed the prevalence and predictors of medication nonadherence among hypertensive patients.
Methodology: A cross-sectional study was conducted among hypertensive patients visiting the outdoor patient department of a tertiary care hospital in North India. Trained investigators interviewed the study participants after obtaining their written informed consent. A validated tool, namely the Brief Medication Questionnaire, was used to assess the medication nonadherence. Statistical analyses were performed using the Epi Info version for Windows.
Results: A total of 400 hypertensive patients participated in the study. The mean age of study participants was 62.8 years (standard deviation = 11.0). Around half (55.0%) of the hypertensive patients suffered from comorbid disease conditions. The prevalence of antihypertensive medication nonadherence was 23.8%. The logistic regression model revealed that patients having a shorter duration of hypertension (odds ratio = 2.2 [1.2–3.9]) and those living in a joint family (odds ratio = 1.7 [1.1–2.8]) had higher medication nonadherence, as compared to their counterparts.
Conclusion: Nearly one-fifth of the study participants were nonadherent to their antihypertension medication. There is a need for designing and implementing effective strategies by health-care providers for increasing antihypertensive medication adherence.
Keywords: Antihypertension medicine, hypertension, nonadherence
|How to cite this article:|
Sharma D, Goel NK, Lehl SS, Walia DK, Puri S, Shukla K, Mishra S. Prevalence and predictors of medication nonadherence among hypertensive patients. Int J Non-Commun Dis 2022;7:71-5
|How to cite this URL:|
Sharma D, Goel NK, Lehl SS, Walia DK, Puri S, Shukla K, Mishra S. Prevalence and predictors of medication nonadherence among hypertensive patients. Int J Non-Commun Dis [serial online] 2022 [cited 2022 Aug 8];7:71-5. Available from: https://www.ijncd.org/text.asp?2022/7/2/71/351742
| Introduction|| |
Hypertension is a leading public health problem worldwide in low- and middle-income countries. It is one of the significant causes of disability and premature mortality. Over the past two decades, the number of people with hypertension has nearly doubled. Hypertension is highly prevalent in Asia, in particular the South Asia region. A systematic review reported the prevalence of hypertension in India to be 29.8%. Another national-level survey in India reported a similarly high prevalence of hypertension (30.7%). Within India, there is a wide variation of prevalence, wherein hypertension is comparatively higher in developed states, urban populations, and individuals from better socioeconomic status. In response to this enormous disease burden, the World Health Organization has set an ambitious target of a 25% relative reduction in the prevalence of raised blood pressure by 2025. The action plan includes implementing public health policies for reducing exposure to behavioral risk factors, establishing integrated programs, promoting activities that encourage adherence to drug treatment, and advancing workplace wellness programs.
Uncontrolled high blood pressure can lead to complications like coronary heart disease, stroke, kidney disease, vision loss, and peripheral artery diseases. Medication adherence is critical in achieving blood pressure control and preventing any associated complications. The possible reasons for medication nonadherence may be either patient related, namely lack of knowledge about the disease complications, financial problems, difficulty in remembering to take medicines, access concerns, or physician-related issues such as lack of trained staff and communication barriers. There are a few studies on medication adherence among hypertensive patients from India, none from the study area. In the absence of such relevant literature from our study area, we conducted this study to assess medication nonadherence among hypertensive patients and identify its predictors.
| Methodology|| |
A cross-sectional study was conducted from September 2021 to November 2021. The study participants were hypertensive adult patients coming for treatment to Outpatient Department (OPD) of Government Medical College and Hospital, Chandigarh. The inclusion criteria were 18 years and above and diagnosed hypertension on antihypertensive medication for at least 6 months preceding the study. Considering a prevalence of 50% for hypertension medication nonadherence, with an allowable error of 5%, 95% confidence level, the estimated sample size was 384 (rounded off to 400). The desired sample size was enrolled from the hospital's outpatient department using a convenience sampling methodology. Each day up to ten hypertensive patients were enrolled in this study using consecutive sampling. If a patient refused to participate, the subsequent patient was approached for inclusion in the study. This process continued till the desired sample size of 400 was achieved. Trained investigators interviewed the study participants after obtaining their written informed consent.
A study participant was considered to be suffering from hypertension based on the medical records available to him/her when visiting the outdoor patient department. The investigator did not record the patient's blood pressure on the study day. The independent variables included in this study were age, gender, education (literate/illiterate), marital status, type of family (nuclear/joint), substance use (using tobacco/drinking alcohol), suffering from a comorbid condition, and duration of hypertension (<10 years and >10 years). The definition of literacy was according to the census of India. Accordingly, a person aged 7 years and above who can both read and write with understanding in any language is considered literate, while a person, who can only read but cannot write, is considered illiterate. A nuclear family refers to a married couple and their unmarried children. A joint family is defined as many married couples and their children living in the same household. All the men in the household are related by blood, and the women are their wives, unmarried daughters, or widows. Comorbidity was defined as the coexistence of any of the following physician-diagnosed disease conditions, namely diabetes mellitus, coronary heart disease, stroke, chronic kidney disease, chronic obstructive pulmonary disease (COPD), thyroid disease (hypothyroidism/ hyperthyroidism), and asthma. Substance use in the present study was defined as the current use of smoking tobacco and/or smokeless tobacco and/or alcohol. A current smoker/smokeless tobacco user was defined as having smoked tobacco/chewed smokeless tobacco at least once in the last 30 days preceding the interview. Similarly, a study participant was considered a current alcoholic if he had consumed alcohol in any amount at least once in the last 30 days preceding the interview. Knowledge of the study participants regarding the cause and effect of hypertension was assessed. The lifestyle activities of study participants were inquired, namely doing exercise, yoga, and eating a diet devoid of high salt content like ketchup, pickle, papad, and chutney. The dependent variable, i.e., medication nonadherence, was assessed using the Brief Medication Questionnaire (BMQ). It consists of four subscales: regimen, beliefs, recalls, and access screens. The regimen screen asks patients how they took medication in the past 1 week, a belief screen asks about drug effects and bothersome features, a recall screen about potential difficulties remembering medicines, and an access screen that evaluates the patient's difficulty in buying refilling their medications in time. Scoring for BMQ is according to the number of positive responses. For the present study, the regimen screen of BMQ was used for classifying the presence or absence of self-reported nonadherence to antihypertension medicine. The remaining subscales indicated the presence or absence of a barrier: belief, recall, and access.
Statistical analyses were performed using Epi Info software for Windows (Centers for Disease Control and Prevention, Atlanta, Georgia, USA). The Chi-square test of significance was used to analyze the univariate factors predicting treatment nonadherence. All factors with P < 0.20 in the univariate analysis were included in the binary logistic regression. Written informed consent was obtained from the study participants. Approval for this study was obtained from the ethics committee of the medical college.
| Results|| |
A total of 400 hypertensive patients were enrolled in the study. The mean age of study participants was 62.8 years (standard deviation = 11.0). There were 165 females (41.3%) and 68 illiterates (17.0%). More than half of them lived in nuclear families (55.3%), and most were married (88.3%). Around half of them were suffering from comorbid disease condition (55.0%), which includes diabetes (35.8%), coronary heart disease (13.8%), chronic kidney disease (6.5%), COPD (4.8%), thyroid disease (4.0%), and asthma (3.0%). Substance use was found in 23% of the study participants (92/400). There were 42 (10.5%) current smokers of tobacco, 22 (5.5%) smokeless tobacco users, and 68 (17.0%) current alcoholics. Regarding the knowledge about the cause of hypertension, most of them attributed it to stress (83.0%) followed by an unhealthy diet (80.3%), inadequate physical activity (76.8%), obesity (75.0%), and smoking tobacco and/or drinking alcohol (68.0%). A minuscule attributed its cause to the curse of God (5.3%). Most of them opined that untreated hypertension could lead to problems (84.8%). Similarly, 81.8% thought that if they do not take medicines regularly, it can lead to some complications. The most common among them are coronary heart disease (64.5%), stroke (35.5%), kidney disease (26.0%), and eye problem (14.0%). While 46.3% of the study participants did exercise, 21% practiced yoga. Nearly half of them had a diet devoid of high salty food items (45.5%), while 23.8%, 23.8%, and 7.0% were consuming high salty food on a daily, weekly, and monthly basis.
Regarding hypertension medication adherence, 23.8% (95/400) of the interviewees were classified as nonadherent to antihypertension medicine treatment. A recall barrier was present in 50.5% (48/95) of study participants, followed by an access barrier in 38.9% (37/95) and a belief barrier in 20% (19/95). In the bivariate analysis, nonadherence to treatment was statistically associated with the duration of hypertension (<10 years, 27.8%, and >10 years, 15.0%) [Table 1]. In the logistic regression analysis, the medication nonadherence was significantly higher among those study participants having a duration of hypertension ≤ 10 years (odds ratio = 2.2 [1.2–3.9]) and living in a joint family (odds ratio = 1.7 [1.1–2.8]), as compared to their counterparts [Table 2].
|Table 1: Predictors of medication nonadherence among the study participants|
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|Table 2: Logistic regression model of predictors of medication nonadherence among the study participants|
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| Discussion|| |
Adherence to hypertension medication is essential for the appropriate management of this chronic disease condition. Several validated scales assess mediation adherence, such as the Morisky Medication Adherence Scale, Medication Adherence Report Scale, Hill-Bone Compliance Scale, and BMQ. In the current study, using the BMQ, we inferred that 23.8% of study participants were nonadherent to hypertensive medication treatment. A nearly similar finding has been reported in a study conducted in southern India using the BMQ (25.6%). However, some studies have documented a higher proportion of medication nonadherence. For example, a study conducted among hypertensive patients in South India using the Self-Report Measure of Medication-Taking Behavior Scale reported that 76% were nonadherent to treatment. In another study conducted by Shankar using the Modified Medication Adherence Scale, it was found that 50.7% were nonadherent to treatment. A study from New Delhi using the BMQ reported that 35.3% were nonadherence to antihypertensive drugs. A study from Ethiopia using the BMQ found that 39.2% of the study participants were nonadherent to treatment. These variable findings across studies may be attributed to the different study populations, study areas, and the scales used for assessing medication adherence.
In our study, medication nonadherence was higher among study participants having a comparatively shorter duration of hypertension. This finding may be explained by the fact that some patients lack the self-perceived need for regular treatment in the initial years. Also, with time the patient's knowledge regarding the disease increases. Continuity of care provided by a health care provider further improves the patients' medication adherence. In addition, some patients may fear medicine dependence in the initial years of disease diagnosis, thus increasing non-compliance. Similar to our study finding, Boratas et al. found a statistically significant association between the duration of hypertension and medication nonadherence. Another study conducted in North-West Ethiopia concluded that long duration of treatment had associations with good antihypertensive medication adherence. Contrary to our finding, Jhaj et al., in their study, reported no association between medication adherence and duration of hypertension.
Our study inferred that patients living in a joint family were comparatively less adherent to antihypertensive medicine treatment. Further detailed investigation regarding the role of family dynamics of the patients in influencing medication adherence may provide valuable insights for interpreting this result. Our study finding is contrary to what has been observed in a study conducted by Nagarkar et al. In our study, we found no relation between comorbidity with medication nonadherence. Contrary to our finding, a study done by Asgedom et al. reported that the adherence level to the prescribed antihypertensive medications was influenced by comorbidity. In our study, we found no relationship between medication nonadherence with age, gender, marital status, socioeconomic status, and level of education. Contrary findings have been reported in a study conducted by Kumaraswamy. Further in our study, we found no relation between hypertension medication adherence and substance use. Contrary to this finding, a study from South India reported that nonsmokers and nonalcoholics were more adherent to hypertension medication.
The strength of our study is using a standardized, validated tool for assessing medication nonadherence. A limitation is the cross-sectional study design which does not indicate causality of association. Second, we did not record a few variables that might have influenced the medication adherence pattern of patients, namely the presence of hypertension-related target organ damage, types of hypertension (primary, secondary, and resistant), polypharmacy, and associated psychiatric illness. These can, however, be included in future research work on this topic.
| Conclusion|| |
Nearly one-fifth of our study participants were nonadherent to treatment. The predictors were comparatively shorter duration of hypertension and living in a joint family. Therefore, it is recommended that physicians focus more on such patients to improve medication adherence. Individual counseling sessions should be held with patients to assess recall, access, and belief barriers. Mobile phone reminder applications and family members' support can address the recall barrier. The access barrier can be addressed by linking them to facilities under the National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular diseases and Stroke, wherein they can have free and sustained access to medications and investigations. Finally, the belief barrier can be tacked by counseling the patient individually and addressing the concern on a patient basis.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]