Assessment of Health Related Quality of Life and Associated Factors among Hypertensive Patients on Treatment at Public Hospitals in Mekelle, North Ethiopia

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Introduction
The overall burden of hypertension related diseases is rapidly rising in the developing world [1]. Hypertension is a prevalent and often asymptomatic chronic disease. A systematic review of prevalence and associated factors in Ethiopia indicates the prevalence of hypertension in Ethiopia ranges from 0.8-31.5% [2].
Despite effective medical therapy and evidence based treatment guidelines for managing high blood pressure, uncontrolled hypertension remains common [3,4]. Low antihypertensive medication adherence has been proposed as an important barrier to achieving hypertension control. Demographic, treatment, clinical and behavioural factors have been shown to be associated with medication adherence, and previous studies have indicated that psychosocial factors are important determinants of antihypertensive medication adherence in older adults [5][6][7][8]. Also, the low rate of controlled hypertension may be associated with worsened quality of life and a high incidence of adverse effects of blood-pressure-lowering drugs [9].
The concept quality of life refers to "the degree to which a person enjoy in the areas of being (who one is: physical being, psychological being, spiritual being), belonging (connections with one's environments: physical belonging, social belonging, community belonging) and becoming (achieving personal goals, hopes, and aspirations: practical becoming, leisure becoming, growth becoming) the important possibilities of his or her life" [10]. It is a broad ranging concept affected in a complex way by the person's physical health, psychological state, level of independence, social relationships, personal beliefs and their relationship to salient features of their environment [11].
Health related QOL (HRQOL) is emerging as an important outcome in hypertension. On the individual level, this includes physical and mental health perceptions and their correlates-including health risks and conditions, functional status, social support, and socioeconomic status. At the community level, HRQOL includes resources, conditions, policies, and practices that influence a population's health perceptions and functional status [12]. HRQOL can be adversely affected by hypertension itself and side-effects of antihypertensive drugs [13]. It is often considered to be equally, if not more important than quantity of life. It is a multi-dimensional element of well-being affected by the physical, mental, emotional and social status of patients, which is increasingly used to assess the health status of the general public and patients, as well as the impact of health care interventions [14].
The assessment of HRQL is a particularly interesting endeavour in patients with hypertension as this condition is traditional risk factor for cardiovascular disease and therefore has a significant impact on the physical, social and mental domains that determine the patients' overall well-being and status. Hypertension is highly correlated with other chronic diseases, such as diabetes and kidney disease [15]. Moreover, assessing HRQOL of Hypertension patients take accounts of their perceived physical and mental health and function which become an important component of health surveillance and are generally considered valid indicators of service needs and intervention outcomes [16]. In addition, the ability to identify indicators of poor healthrelated quality of life (HRQoL) is crucial for both improving clinical care and determining targets of intervention for the prevention and treatment of disease [12]. Furthermore, assessing health status also proved to be more powerful predictor of mortality and morbidity than many objective measures of health [17].
However, the impact of hypertension on individual's physical and mental quality of life is less clear. We couldn't find published article that addresses this issue in the country. Therefore, the aim of this study is to assess the HRQoL profile of the hypertensive patients, and to determine the socio-demographic and clinical characteristics associated with poor HRQoL.

Study area
The study was carried out in Mekelle town, a capital city of Tigray regional state, northern Ethiopia, which is located at 780 km from Addis Ababa, capital of Ethiopia. There are three general hospitals and one referral hospital, which provides a broad range of medical services to both in and out patients of all age groups.

Study design
An institution based cross sectional study design was employed.

Study population
All hypertensive patients on follow up at chronic clinics who met the inclusion criteria were included in the study.

Eligibility criteria and inclusion criteria
Patients with age 18 years and above.

Exclusion criteria
Patients who denied consent for the interview. In-patients.

Sample size and sampling technique
Sample size calculation: Sample size was determined using data from a previous study, where the SD for HRQOL scores in hypertensive patients was 15.61 and assuming an alpha of 0.01 and a 2 tailed test with CI of 5 points. The total sample size was 255 [18].
Sampling technique: To get the number of patient to be taken from each hospital, proportionate allocation formula was employed. Patient's card number was used as a sampling frame and individual patients were selected by using simple random sampling technique from each hospital.

Operational definition
Physical health subscales: Includes physical functioning, role limitations due to physical health problems, bodily pain, and general health perception.
Mental health subscales: Includes social functioning, role limitations due to emotional problems, mental health and vitality.
Low HRQOL: Because no previously established cut points for defining the scores are available, participants were categorized as having low HRQOL if their score is in the lowest tertile of the distribution for the current study population.

Data collection instrument
Health related quality of life was measured using a generic tool SF-36. The tool is comprised of 36 questions that measure four physical health subscales (physical functioning, role limitations due to physical health problems, bodily pain, and general health perception) and four mental health's subscales (social functioning, role limitations due to emotional problems, mental health and vitality) and has previously been used to measure health related quality of life in similar populations.

Data collection procedure
Data were collected when the patient comes for follow up by using a pre tested structured questionnaire, and by reviewing patient chart. Patients were approached after they finished consultation with physician. Their socio demographic characteristics and clinical data were noted. The items were formulated in a manner that elicits the required data from the chart.

Data analysis procedure
Scores on each of the eight subscales were calculated. Subscales were weighted and aggregated to create PCS and MCS summary scores. Quantitative variables were expressed as mean and standard deviation. Qualitative variables were expressed as absolute numbers and percentages. Multivariate analysis was performed by constructing a model for each outcome. The HRQOL score was considered as outcome. Socio-demographic and clinical variables were used as explanatory variables and were considered a candidate for multivariate analysis when they had p values <0.20 in the bivariate analysis. In the multivariate analysis the level of significance was set at p<0.05.

Data quality management
An English version of SF-36 is adopted and was translated to Tigrigna and retranslated back into English. Four BSc nurse data collectors were trained ahead of the actual data collection period. The training was focused on familiarizing interviewers with the questionnaire and giving them the opportunity to practice using it. At time of data collection filled questionnaires were checked for completeness and consistency of information by the supervisor on daily basis and typographic errors were manually edited.

Ethical Consideration
Before the data collection, ethical clearance letter was obtained from ethical review committee of Mekelle University College of health science. Respondents were informed about the purpose of the study, and their oral consent was obtained. The respondents' right to refuse or withdraw from participating in the interview was fully maintained and the information provided by each respondent was kept strictly confidential.

Socio-demographic characteristics
Out of the total 255 study participants planned, 243 study participants were interviewed using structured questionnaires with a response rate 95.3%. From the 243 study participant 93 (38.3%) of them were male and 150 (61.7%) of them were female. The mean age of the participants was 55 years. Majority of the respondent 231 (95.1%) of them were orthodox followers followed by Muslim 8 (3.3%). Most, 223 (91.8%) of the participant were Tigray in their ethnicity. One hundred forty nine (61.3%) and 53 (21.8%) of subjects were married and widowed respectively. Regarding their educational status, 91 (37.9%) of them were illiterate and 43 (17.9%) were with diploma and above educational level. Majority of the participants 161 (66.3%) of them they can access health care with less than 1 hour time and for 82 (33.7%) of the participants more than one hour is needed to access treatment (

Clinical factor
From the study participants, 96 (39.9%) of them knew they have hypertension less than one year period while 59 (24.3%) have been diagnosed for the last three years and above. 10 (4.1%), 11 (4.5%) of them have the complaint of swelling and kidney problem respectively. Majority of them, 156 (64.2%) took only one medication and 87 (35.8%) took two and more medication with frequency of 188 (77.4%) took once a day and 55 (22.6%) of them twice and more per day (Table  3).

Variable Category Frequency Percentage
Year since diagnosis

Health related quality of life of hypertension patient
Using the generic tool SF-36 this study assessed the eight domain of HRQOL. Though the scores of all domains found to be above average, there is a marked difference between the eight domains.
The physical functioning and general health mean score were found to be little above average. The bodily pain mean score (87.77) was recorded to be the highest score from all physical and mental component domains.

Factors associated with HRQOL
To identify predictor variables, logistic regression has been done. At the beginning, the association of all independent variables with quality of life has been assessed using bivariate logistic regression. Among socio-demographic variables, age of the respondent, marital status, occupation, level of education, monthly family income and distance from health care facility were found to be associated with HRQOL (  Bivariate analysis also showed significant association between duration of hypertension, presence of health complaint, Blood pressure status and presence of co morbidity and HRQOL (Table 7).  Multivariate logistic regression was performed by constructing a model for HRQOL as an outcome variable. Socio-demographic and clinical variables were used as explanatory variables and considered when they had <0.2 P-values in bivariate analysis.
When assessing the effect of Socio-demographic factors on the HRQOL, it was revealed that HRQOL was significantly influenced by marital status and level of education of the study participants.
The findings of this study showed that those patients who got divorced had less chance (OR=0.21 CI=0.08-0.55) of having good quality of life compared to those who are married. Regarding level of education the current study demonstrated that those who are illiterate were found to have lower quality of life than those who completed at least grade 7 to 12(OR=3.25 CI=1.47-7.2) and have a college diploma and above(OR=23.1 CI=5.5-97.2). Regarding clinical factors, HRQOL was found to be influenced by, duration of hypertension, Presence of health complaint and blood pressure status.
The findings of this study showed a significant association between duration of hypertension and quality of life, in which the odds of good HRQOL was lower in those who were diagnosed with in the past three years compared with those who have known their diagnosis before 3 years.
On the topic of blood pressure status, our study revealed those participants who had controlled their blood pressure had 4.2 (OR=4.2 CI=4.2 (1.88-9.33) times higher chance of having good quality of life than those who didn't control their blood pressure.
Based on the finding of the study, participants who had no health complaint like, paralysis of the limb, visual impairment, swelling/ edema and other had higher (OR=4.2) chance of having good quality of life than their counterpart (

Discussion
For many chronic diseases like hypertension assessing Health related quality of life can help in evaluating the physical and psychosocial impact of these diseases on the affected population. It could be also used as important outcome measure for different therapeutic interventions (Figure 1). The SF-36 scale is a generic instrument available in different language and had been used to assess quality of life in many chronic disease conditions.
In this study the physical health component summary mean score and mental health summary mean scored are 64.83 and 64.88 respectively. This finding is consistent with similar studies conducted in Nigeria and Brazil [18,19]. The lowest scores from the SF-36 domains were Physical function and vitality. The lower quality of life on this physical domain may be explained by the fact that the SF-36 scale is more associated with physical illness. In addition, the lower score in Vitality domain may be explained by lack of disposition and enthusiasm and because of the association of hypertension with symptoms such as headache, anxiety and the effects of antihypertensive drugs such as fatigue and sleep disorders.
In this study there is a positive association between educational level and quality of life. This finding agree with other similar studies conducted in Nigeria, Brazil and Pakistan which showed study participants with a higher educational level also had a higher HRQOL [18][19][20]. This association may be explained by the fact that education develops a level of interest and concern in patients related to improving their own health, which is a key determinant of successful medical treatment. In addition, it is a common observation that bettereducated people are less likely to develop complications to chronic conditions, or are often in the "controlled" status. In addition to pharmacotherapy, better-educated patients are more likely to adapt to life style modification and preventive measures which result in an improvement in HRQOL.
Regarding other Socio-demographic characteristics our study revealed a statistically significant association between marital status and quality of life. Those participants who got divorced had a lower chance of having good quality of life than those who were married. This finding is in not in accordance with many studies, which showed no significant association between these variables. But few studies showed an association between physical function domain and any of the eight domains respectively [19][20][21].
Evidence from this study showed a good HRQOL among participants who had no health complaint/symptoms. The finding is consistent with previous studies done in Nigeria and India which shows a positive correlation between number of symptoms and quality of life [22].
Our study found out that there is a positive association between duration of hypertension and quality of life, showing a good quality of life among participants who knew their diagnosis before 3 years. This is in disagreement between many studies which showed no statistically significant association between these variables [18,19,[22][23][24][25].
The relationship between blood pressure status of the participant and HRQOL was also found to be statistically significant, in which participants having increasing/uncontrolled blood pressure were less likely to had good quality of life than their counterparts. The result is consistent with similar studies [18,[21][22][23][24][25]. Even though patients with elevated blood pressure mostly have no physical symptoms but may have behavioural or emotional impairment which lowers their quality of life.

Conclusion
From the results of our study, HRQOL in hypertensive patients was still suboptimal. In this study we found that education, marital status had marked effect on HRQOL in hypertensive patients. HRQOL was significantly better in the group of hypertensive that had controlled blood pressure. Duration of hypertension, presence of health compliant were also found as major predictor of HRQOL among hypertension patient.