Knowledge and Associated Factors of Blood Pressure Control Among Hypertensive Patients Attending Chronic Illness Follow-Up Clinic at University of Gondar, Comprehensive Specialized Hospital, Northwest, Ethiopia

Introduction

Hypertension or high or raised blood pressure is one of the most common public health problems which is exceeding the epidemics of communicable diseases. It has been rising due to changes in lifestyle and increasing urbanization.¹ It is a chronic cardiovascular disorder that contributes to heart disease, stroke, kidney failure, and premature mortality and disability. The prevalence of hypertension exceeds 1.3 billion worldwide.² In Ethiopia, the prevalence increased from 17.7% in 2010 to 19.6% in 2015.^2,3

According to the global brief report 2015, there were 3 in 10 deaths due to CVD (cardiovascular diseases), and half of all of the deaths were related to uncontrolled BP (Blood pressure). The WHO (World Health Organization) action plan for the prevention and control of NCDs (non-communicable diseases) is the reduction of raised blood pressure by 25%. However, the prevalence is still projected to be 60% and will reach 1.56 billion by 2025, with the largest proportion in low and middle-income countries.^4,5

Good knowledge of blood pressure control was reported from Southern Iran (25.2%), Armenia (50.23%), Saudi Arabia (54.7%), Pakistan (55%), Brazil (82.3%), and India (27.68%).^6–11 A study in India showed 43.6% of good knowledge about lifestyle modification regarding blood pressure control.¹² Similarly, it was 14% in Cameron,¹³ 47.1% in Nigeria,¹⁴ 8.9% in Egypt⁶ and 61.39% in Addis Ababa, Ethiopia.⁷ In Nigeria, 32.7% of the participants were knowledgeable about the use of exercise to control blood pressure.⁸

Studies in various parts of the world revealed the association between BP control knowledge and age, sex, marital status, educational level, occupation, income, presence of chronic disease and duration of hypertension.^9–11,15 Good knowledge of blood pressure control was associated with the level of education, duration of follow-up, access to information and sometimes with socioeconomic status.^12,16 In Nigeria, secondary or tertiary education was significantly associated with the knowledge of self-monitoring and lifestyle modification to control BP.^17,18

Addressing the knowledge of behavioral risk factors, like unhealthy diet, smoking, harmful use of alcohol, and physical inactivity can be crucial to prevent and control raised blood pressure.¹ Although there have been studies on the prevalence of hypertension in Ethiopia, knowledge about BP control and associated factors were not well studied. Therefore, this study will determine the knowledge level and associated factors towards blood pressure control among hypertensive patients.

Methods

Study Design and Period

An institutional-based cross-sectional study was conducted on hypertensive patients from March to April 2018.

Setting

The study was conducted at Gondar University comprehensive-specialized hospital, northwest Ethiopia. The hospital is found in Gondar town, Amhara National Region State 735 km from Addis Ababa (the capital of Ethiopia) and is one of the teaching hospitals in the country serving around 7 million people both in and outside of the town. It has a follow-up clinic, for the major chronic illnesses, including hypertension, in the Department of Internal Medicine staffed with internists, internal medicine residents, interns, and nurses. There were on average of 848 hypertensive patients on follow-up in the clinic during the study.

Study Population

All adult hypertensive patients attending at chronic care follow-up clinic at Gondar University comprehensive-specialized hospital and had at least one follow-up during data collection. Patients who were seriously ill and had difficulty in communication were excluded.

Sample Size Determination and Sampling Procedure

The sample size was determined using the single population proportion formula with the assumption of a 95% level of confidence and a 5% marginal error. Since there were no similar studies in Ethiopia about the knowledge of both medical and non-medical control of blood pressure, 50% was assumed and yielded the required sample size of 404 with a 5% nonresponse rate.

Using systematic random sampling, every other participant was interviewed based on their order of arrival. To avoid the recycling of data’s special marks were used in patients’ medical charts and it was strengthened by verbal confirmation whether they participate or not in the previous consecutive data collection time.

Data Collection Tools and Procedures

Data were collected by using a structured interviewer-administered questionnaire prepared by reviewing related published studies^15,19–22 that included socio-demographic, knowledge, and clinical characteristics. Knowledge about blood pressure control was measured by eight interviewers administered questions collected by four trained BSc degree graduate nurses. The data collected in 25–30 mins were computed by coding the correct responses as “1” and the incorrect ones as “0”. Then, the correct answers were added up and participants who scored the mean and above were labeled as having good knowledge (Additional file 1).

Data Quality Control

The questionnaire was pre-tested on 21 hypertensive patients a week before the actual data collection. Based on the findings of the pretest modifications were made on vague questions and the flow of the items. A one-day training was given to data collectors and supervisors. The data were checked for completeness during collection, entry and analysis.

Operational Definition

Knowledge was measured by calculating the mean score and categorized as “knowledgeable” if individuals scored the mean and above or “not knowledgeable” if they scored less than the mean.⁷

Data Processing and Analysis

The data were checked for completeness and coded before entry and Epi info version7 and SPSS version 20 were used for analysis. Descriptive statistics, including frequencies, percentages, means and standard deviations were used to describe the data. The binary logistic regression analysis was used, and variables with < 0.2 p-values were entered into the multivariable logistic regression for final analysis. Variables with a ≤ 0.05 p-values were considered statistically significant.

Result

Socio-Demographic and Clinical Characteristics

In the study, 404 hypertensive patients participated with a response rate of 97.3%. The mean age of respondents was 59.1 years (SD=±12.773). Over half, 212 (53.9%) and 232 (59.0%), of the respondents were male and urban dwellers, respectively; more than two-thirds (71.2%) were married, and 34.1% classified low economic status according to the principal component analysis (PCA). The major sources of information for 332 (84.5%) participants about healthy lifestyle to control BP were health professionals, followed by the mass media for 206 (52.4%). More than half of the participants 205 (52.2%), had 1–5 years of follow up. Participants with comorbidity were 87 (22.1%) (Table 1).

Table 1 Socio-Demographic and Clinical Characteristics of Participants Attending in Chronic Illness Follow-Up Clinic of Gondar University Comprehensive Specialized Hospital, Northwest, Ethiopia, 2018 (n=393)

Knowledge About High Blood Pressure and Its Controls

Out of 393 participants, 203 (51.7%) of whom 125 (61.6%) had ≥ 5 years of follow-up were knowledgeable about the control. The mean (±SD) score for correctly answered knowledge questions was 17.695 (±6.261). Participants who correctly responded to the definition of increased blood pressure were 55.0%. Stress, smoking and alcohol consumption were identified as the risk factors for the problem by 78.8%, 45.7% and 44.6% of the respondents, respectively (Table 2).

Table 2 Frequency Distribution of Knowledge Response About Blood Pressure and Its Control Among Hypertensive Patients Attending Chronic Illness Follow-Up Clinic, Gondar University Comprehensive Specialized Hospital, Northwest Ethiopia, 2018 (n=393)

Knowledge About Signs and Symptoms

In the study, 76.9%, 53.8%, 53.1%, and 54.4% of the participants pointed out headache, dizziness, blurring of vision and fatigue as the signs and symptoms of high blood pressure, respectively. Only 9.5% of the participants failed to know the signs and symptoms of raised BP (Figure 1).

Figure 1 Knowledge of participants about signs and symptoms of high blood pressure (n=393).

Factors Associated with Participant’s Knowledge of Blood Pressure Control

Sex, residence, level of education, occupation, family history of hypertension showed significant associations with knowledge of blood pressure control. Female participants were 3.79 (AOR= 3.79, 95% CI (1.55, 9.28)) more knowledgeable than males. Rural dwellers were 82% (AOR=0.18, 95% CI (0.11–0.98)) less knowledgeable than urban dwellers. The odds of being knowledgeable were 2.80 (AOR= 2.80, 95% CI (1.44, 5.46)), 8.05 (AOR=8.05, 95% CI (2.93, 22.10)), and 7.53 (AOR=7.53, 95% CI (2.52, 22.49)) more likely among participants who had read and write, secondary school, and preparatory and above educational status compared to cannot read and write group, respectively. In this work, occupation was significantly associated with knowledge. Merchants 7.66 (AOR=7.66, 95% CI (3.01, 19.47)), government employees 6.33 (AOR= 6.33, 95% CI (1.90, 22.07)), and the self-employed were 4.58 (AOR=4.58, 95% CI (1.80, 11.70)) times more likely to be knowledgeable compared with farmers, respectively. Respondents with family history of hypertension were 2.36 (AOR=2.36, 95% CI (1.42, 3.92)) times more likely to be knowledgeable than their counterparts (Table 3).

Table 3 Univariate and Multivariate Analysis for Knowledge Towards Blood Pressure Control Among Hypertensive Patients Attending Chronic Illness Follow-Up Clinic, Gondar University Comprehensive Specialized Hospital, Northwest Ethiopia, 2018 (n=393)

Discussion

The current study showed that more than half of the participants, 51.7% (95% CI = 46.8–56.8), were knowledgeable about blood pressure control. This finding is in line with those of studies conducted in Saudi Arabia (52%), Armenia (50.23%), India (52.5%), and Pakistan (55.0%).^15,21,23,24

The finding was lower than those of studies done in Bishoftu (72.27%), and Brazil (82.3%).^7,25 The difference might be that the study in Bishoftu was only on non-pharmacological blood pressure control, and the majority of the participants were urban dwellers. On the other hand, the study in Brazil was community-based with a convenient sampling. Our finding is higher than the results of studies done in Iran (25.6%), Karnataka (41.61%), another study in India (27.7%), Nigeria (47.1%), Cameroon (14.0%), and another study in Nigeria (43.6%).^{13,14,20,26,27} The difference might be due to variations in sociodemographic characteristics of participants and the type of health facilities. The current study was done in a compressive-specialized hospital, but the comparative studies were carried out in health facilities including the health centers.

This study showed that 54.96% of the participants correctly answered the questions on blood pressure control methods. In Ghana, however, 87.0%, 64.2% and 54.0% of the participants correctly identified drugs, diets, and exercises as methods of blood pressure control, respectively.²⁸ Similarly, in Samarkand State Medical Institute 71.3% and 51.7% of the participants knew that medicine was the most important factor in controlling BP and that eating less salt usually made BP lower, respectively.²⁹

In this study, sex, family history of hypertension, education, occupation, and residence were factors associated with blood pressure control knowledge. Females were 3.79 (AOR= 3.79, 95% CI (1.55, 9.28)) times more knowledgeable about blood pressure control than males. In the cross-tabulation of sex and educational status, females had a higher educational status than males. Participants with more education could have a better understanding and can easily access information. So, the significant association of females with knowledge might be related to this fact. However, in Southern Iran, the level of knowledge about hypertension and its control was higher among males (27.1%) compared to females (23.9%).³⁰ Respondents with family history of hypertension were 2.36 (AOR=2.36, 95% CI (1.42, 3.92)) times more knowledgeable compared to their counterparts. These findings were supported by studies conducted in Armenia and China and reported that family history had a high chance of making knowledgeable.^9,15 This was however inconsistent with study conducted in South Iran and reported that family history was not a significant predictor of knowledge about blood pressure control.²⁷

The odds of being knowledgeable about the control of blood pressure among the “can read and write”, and those who had primary, secondary, and preparatory school and above educational status were 2.8, 1.4, 8.05, and 7.53 times better, respectively, compared with the “can’t read and write”. Educated individuals could access information about blood pressure control mechanisms through content materials, like leaflets and manuals which might make them aware of BP control. They can also easily communicate with health care providers when they have doubts. The finding is supported by a study in Iran in which the proportion of the control of hypertension was higher among the educated compared with not educated.³⁰

Rural residence decreased the chance of being knowledgeable by 82% (AOR=0.18, 95% CI (0.11–0.98)) compared to urban dwellings because rural dwellers had less access to the media and reading materials since most of them could not read and write. A study in India showed rural residence was associated with greater losses from hypertension follow-up care.³¹ Compared to farming, government employment increased the chances of being knowledgeable six-fold. This was supported by a study conducted in Ghana in which respondents who were employed scored better than the unemployed in knowledge.³²

Conclusion and Recommendation

The knowledge of blood pressure control in this study was lower compared to the finding of a study done in Bishoftu, Ethiopia. But it was higher than those of studies in other African countries. Measures need to be taken to improve the pharmacological and non-pharmacological knowledge of participants so they could control their BP. Perhaps, future qualitative studies are necessary for detailed understanding of the problem and suggesting informed remedies.

Strengths and Limitations

To the best of our knowledge, the study has comprehensively evaluated HTN control knowledge among patients. However, it is an institution-based study that might not be generalized to the public. Besides, it has not assessed the blood pressure level of the participants in terms of their own knowledge.