International Journal of Medicine and Health Development

: 2022  |  Volume : 27  |  Issue : 3  |  Page : 226--232

Prevalence of Controlled Blood Pressure among Hypertensive Patients and Determinants of Hypertensive Complications in a Nigerian Population

Chukwukasi W Kassy1, Chinyere C Okeke2, Anne C Ndu2, Ancilla K Umeobieri2,  
1 Department of Community Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria
2 Department of Community Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu, Nigeria; Department of Community Medicine, College of Medicine, University of Nigeria, Enugu Campus, Nigeria

Correspondence Address:
Chukwukasi W Kassy
Department of Community Medicine, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu


Background: The impact of uncontrolled hypertension results in undesirable cardiovascular events. Hence, there is a need to emphasize on adequate control of blood pressure. Objectives: The objectives of this study were to determine the prevalence and determinants of controlled blood pressure and the complications of hypertension in a tertiary hospital in Nigeria. Materials and Methods: This was a retrospective study of 257 patients of Cardiology Unit of University of Nigeria Teaching Hospital diagnosed with hypertension from 2014 to 2018. A proforma-designed questionnaire was used to retrieve responses from the patients’ medical records. Data were entered and analyzed using Statistical Package for Social Sciences version 20. The level of significance was set at 0.05. Results: The prevalence of controlled blood pressure was 35.8% with mean blood pressure of 112.39/72.72 mmHg. Adherence to drug therapy was found to be associated with controlled blood pressure (χ2 = 8.370, P = 0.005). Two-thirds of patients diagnosed with hypertension developed complications of which hypertensive heart disease, stroke, and chronic kidney diseases were the commonest. Age (χ2 = 9.629, P = 0.008) and the initial presenting diagnosis (χ2 = 7.662, P = 0.004) were factors associated with the development of complications. Conclusion: Adequate blood pressure control is still a challenge among hypertensive patients in the study population. A comprehensive program is advocated for the control of blood pressure that will accommodate drug adherence in addition to education, and socio-behavioral change modifications.

How to cite this article:
Kassy CW, Okeke CC, Ndu AC, Umeobieri AK. Prevalence of Controlled Blood Pressure among Hypertensive Patients and Determinants of Hypertensive Complications in a Nigerian Population.Int J Med Health Dev 2022;27:226-232

How to cite this URL:
Kassy CW, Okeke CC, Ndu AC, Umeobieri AK. Prevalence of Controlled Blood Pressure among Hypertensive Patients and Determinants of Hypertensive Complications in a Nigerian Population. Int J Med Health Dev [serial online] 2022 [cited 2022 Jun 26 ];27:226-232
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Full Text


Hypertension is a chronic medical condition known as high or raised arterial blood pressure causing the heart to pump harder.[1],[2] It is defined as measured blood pressure ≥ 140 mmHg systolic or ≥ 90 mmHg diastolic.[3] Blood pressure between systolic value of 120–139 mmHg and diastolic value of 80–89 mmHg is regarded as pre-hypertensive or borderline hypertension, blood pressure that does not necessitate initiation of drug therapy.[3] However, the American College of Cardiology and American Heart Association (AHA) guidelines advocated for treatment at 130/80 mmHg or “stage 1” hypertension in those with cardiovascular events.[4] The progressive changes in classification of hypertension from 140/90 mmHg in 2003 have increased awareness and changed the prevalence of hypertension in Nigeria from 10.1–13.3% and 8.9% in the late sixties to between 38.8–44.5% and 34.8% recently in rural and urban communities, respectively.[5] The cause of hypertension is multifactorial and includes genetic factors, race, socio-economic and behavioral factors, and metabolic factors.[2] Hypertension is an important risk factor for cardiovascular diseases (CVDs) and one of the major contributors of global disease burden.[6] The CVDs are as a result of uncontrolled hypertension and include stroke, heart failure, ischemic heart disease, kidney failure, and ocular disease.[7] The control of hypertension is achieved by a combination of lifestyle modifications, early screening including home screening using a validated sphygmomanometer, and treatment using drugs.[2],[8]

With an increasing adult population and changing lifestyle, the burden of hypertension continues to increase. It is estimated that hypertension affects about 1 billion people all over the world.[9] It contributes to 13.5% of deaths and 6% of disability-adjusted life years (DALYs) globally, of which 12.9% and 5.6%, respectively, were from low- and middle-income countries.[10] It is projected that by 2025, 75% of world hypertension will be in developing countries.[7] In Nigeria, the prevalence of hypertension varies from 7.9% to 50.2% and 3.5% to 68.8% in men and women, respectively. The impact of uncontrolled hypertension is responsible for 44.1–78.7% of hypertensive heart disease, 80% of stroke cases, 53% of ischemic or coronary heart diseases, 36.6–51% of chronic kidney disease, and 4.6–13% of retinopathy.[7] However, the prevalence of controlled hypertension in Nigeria ranged from 24.2% to 42.7%.[8] To negate the impact of uncontrolled hypertension, more focus should be on control of hypertension and hypertensive-related cases in our hospitals, the proportion-controlled, and the reasons for default. This will help to understand the best protocol to control hypertension and to limit the magnitude and burden of hypertension-related CVDs. This study is aimed at determining the prevalence and risk factors associated with controlled blood pressure and complications of hypertension in a tertiary hospital retrospectively for 4 years.

 Materials and Methods

The study was conducted at the University of Nigeria Teaching Hospital (UNTH), Ituku/Ozalla, Enugu State, South East Nigeria from May to July 2019. The hospital is a federal tertiary hospital and one of the two tertiary hospitals in the state.

The study was a retrospective study design. All patients of the cardiology unit diagnosed and those on treatment for hypertension or hypertension-related diseases from 2014 to 2018 were selected. Those who have not maintained up to three or more visits while on treatment for hypertension or hypertension-related diseases were excluded from the study.

A total of 257 folders were selected from the Medical Records Department of the hospital at an average rate of 25 per workday for a total of 2 weeks. Data were collected using research assistants who were two resident doctors. They were trained for 2 days, 2 h per day on the objectives of the study and variables to be entered on the questionnaire. A proforma-designed questionnaire in line with the objectives of the study adapted from literatures was used to retrieve relevant responses from the folders.[8],[11],[12] The responses were on socio-demographic, diagnosed hypertension, risk factors, and comorbidities. Those diagnosed as hypertensives were those with blood pressure reading ≥ 140/90 mmHg, whereas folders checked within the period of study, on treatment, and with blood pressure <120/80 mmHg were taken as controlled blood pressure.[3] Cardiovascular complications were also recorded.

Data were entered and analyzed using Statistical Package for Social Sciences (SPSS); categorical variables were summarized using frequency tables and proportion, and continuous variables were summarized using mean and standard deviation. Comparison of variables was done using χ2. The level of significance was set at 0.05.

Ethical approval was obtained from the Health Research Ethics Committee of UNTH, Ituku/Ozalla, Enugu, Nigeria.


The mean age was 60.46 ± 13.90 years, with age ranging from 23 to 97 years of age. The greater proportion of hypertension was among ages 40–80, with fewer at the extremes of ages. More males than females presented with hypertension. Almost all the people are of Igbo ethnic group and Christian religion. About three quarters were married. The commonest level of education attainment was is primary education followed by secondary. Trading and farming were the commonest occupation with more than half residing in rural areas [Table 1].{Table 1}

Hypertension alone was the commonest presentation at diagnosis of raised blood pressure followed by presentation of hypertension with complications, of which the commonest were hypertensive heart disease and cerebrovascular accidents. The mean blood pressure at diagnosis was 160.48/94.66 mmHg, with grade 1 hypertension the commonest stage of presentation, followed by grades 2 and 3. The prevalence of controlled hypertension after three visits or at the end of the study was 35.8% with mean blood pressure at control noted to be 112.39/72.72 mmHg [Table 2].{Table 2}

Fewer people, 18.9%, 39.7%, and 19.1% were found to currently smoke, take alcohol, or have family history of alcohol, respectively [Table 3].{Table 3}

In achieving control of blood pressure, 61.1% and 58.8%, respectively, adhered to clinic attendance and intake of prescribed medications, whereas 28.4% and 10.5%, respectively, engaged in dietary modification and regular exercise [Table 4].{Table 4}

About two-thirds were diagnosed with hypertensive-developed complications, of which hypertensive heart disease 53.1%, stroke 32.6%, and chronic kidney diseases 23.4% were the commonest [Table 5].{Table 5}

Among the modifiable factors employed in the control of hypertension, adherence to drugs is the only factor associated with controlled hypertension (χ2 = 8.370, P = 0.005) [Table 6].{Table 6}

The progression of cases to complications seen at the end of the study was significantly associated with age (χ2 = 9.629, P = 0.008) and the presenting diagnosis (χ2 = 7.662, P = 0.004) [Table 7].{Table 7}


Hypertension is a chronic medical condition whose management involved application of multi-therapies over the course of patients’ lifetime aimed to achieve a controlled blood pressure at all times and to avoid complications of hypertension with disabilities.[2],[8] It should be noted that the multi-therapeutic approach if not judiciously followed by both patient and healthcare provider may result in poor blood pressure control and consequent complications. Hence, the importance of adequate blood control or control hypertension is not the same all over the world.[8] This study found that the prevalence of controlled blood pressure was 35.8%, with the blood pressure being 112.39/72.72 mmHg. This is low considering the increasing awareness on hypertension and associated complicated since the continued review on the criteria for the diagnosis by Joint National Committee (JNC) and American College of Cardiology (ACC)/ American Heart Association (AHA). This prevalence is within the range of findings from studies done in Northern Nigeria (42.7%), South Africa (34% in males and 44% in females), Cuba (39%), and USA (34%).[3],[13],[14],[15] This similarity is due to related methodology of higher sample size and retrospective study design over a period of at least 4 years in which reviewed cases were followed up for years of treatment. Findings differed from findings of studies done in Port Harcourt, Nigeria (24.2%), Ghana (2.8% and 6.2%), Canada (17%), and Europe (10%).[8],[16],[17],[18] This difference is due to methodological differences, prospective study of 3 months, and cross-sectional study conducted in Port Harcourt and Ghana, whereas population or racial difference could be the reason for difference in Canada and Europe. The difference and similarity could be due to absence of standardized defined meaning of controlled blood pressure and blood pressure-controlled program.

Findings from this study showed that among the factors employed in the control of blood pressure among hypertensive patients in UNTH from 2014 to 2018, only adherence to drugs was associated to controlled blood pressure. This could be due to emphasis on daily consumption of drugs mainly by the healthcare providers. The socio-behavioral factors and clinic attendance were found not to be associated with controlled blood pressure. However, it should be noted that these factors were not ascertained in most retrieved folders. This findings were consistent with the study in Port Harcourt which used a longitudinal study but differed with the study in South Africa in which behavioral factors were found as predictors of control blood pressure.[8],[14] This showed poor emphasis on lifestyle modification and possible other promotive factors such as health education as a vital component of blood pressure management.

Despite the widely noted varied prevalence and associated factors of blood pressure control around the world, adequate blood pressure control is still a challenge accounting for the high prevalence of hypertension-associated complications and disabilities. This could be due to the absence of comprehensive program for control of blood pressure that involves both the healthcare providers and the patients who should be friendly and promotive. This promotive, preventive, and curative program should include specified socio-behavioral and dietary modification programs recorded by patients and reviewed by healthcare providers, a validated sphygmomanometer usable and recorded by patients at home, and combination treatment that ensures adherence. This program if instituted will ensure a proper definition of what constitutes controlled blood pressure in terms of measurements and duration of normal readings. This, if further distributed community-wise to secondary and primary healthcare facilities, will be far reaching and will standardize further study on blood pressure control.

Among hypertensive patients who visited the Cardiology Clinic of UNTH from 2014 to 2018, about two-thirds were found to develop complications of hypertension as a result of uncontrolled hypertension. This agreed with studies that noted high deaths and DALYs in uncontrolled hypertension.[9],[10] More work is needed to improve on the needed knowledge and intervention for blood pressure control to negate the impact that would likely occur as projected that by 2025; 75% of world burden of hypertension will be in the developing world.[7] The commonest complications of uncontrolled hypertension were hypertensive heart disease, cerebrovascular disease, chronic kidney disease, and retinopathy. This resonates with findings from Nigeria.[7] Those who developed complications due to uncontrolled blood pressure were found to be associated with age and the presenting diagnosis either as hypertension or comorbidity. This agreed with studies done in CA, USA, Spain, and Thailand.[19],[20],[21] Most hypertensive diagnosis is already late because of symptomless presentation at the early stage unless accidentally detected or the presentation is due to target organ damage (TOD). The TOD presentation mostly in the form of headache, poor sleep, dizziness, chest pain, etc. increases with increasing age. Also most presentation of hypertension is with comorbidity either due to hypertension or itself causing hypertension. This situation with increasing age is the common reason for multiple drug therapy, which also was found to be associated with uncontrolled blood pressure.[19] The above reasons are worse in low-income countries in which out-of-pocket health expenditures are high leading to the choice of over-the-counter drugs and self-medication without routine blood pressure checks. Health insurance coverage is also low that would have encouraged the utilization of hospital for standardized care and possible discovery of early onset hypertension.


The study is specific to one area and the findings cannot be generalized.


The prevalence of control hypertension was found to be 35.8% and was associated with adherence to drug treatment. The prevalence of complications due to hypertension was found to be 61.8%, which was associated with age and presence of comorbidities at diagnosis.


A comprehensive program is advocated that will accommodate education, socio-behavioral change modifications, and drug therapies to ensure quality of care at all times. This can be distributed to communities for use and serve to periodically evaluate the outcome of controlled blood pressure management. Awareness of routine blood pressure check among people above 40 years is highly advocated to prevent complications and comorbidities.

Authors’ contributions

All authors participated in the conception or design of the work, acquisition, analysis, or interpretation of data and in drafting the work or revising it critically for important intellectual content and final approval of the version to be published.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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