Background: Hypertension (HTN), characterized by an elevation of blood pressure, is a serious public health chronic condition that significantly raises the risks of heart, brain, kidney, and other diseases. In South Africa, the prevalence of HTN (measured objectively) was reported at 46.0% in females, nonetheless little is known regarding the prevalence and risks factors of self-reported HTN among the same population. Therefore, the aim of this study was to examine determinants of self-reported HTN among women in South Africa. Methods: The study used data obtained from the 2016 South African Demographic and Health Survey. In total, 6,027 women aged ≥ 20 years were analyzed in this study. Self-reported HTN was defined as a case in which an individual has not been clinically diagnosed with this chronic condition by a medical doctor, nurse, or health worker. Multiple logistic regression models were employed to examine the independent factors of self-reported HTN while considering the complex survey design. Results: Overall, self-reported HTN was reported in 23.6% (95% confidence interval [CI], 23.1–24.1) of South African women. Being younger (adjusted odds ratio [aOR], 0.04; 95% CI, 0.03–0.06), never married (aOR, 0.69; 95% CI, 0.56–0.85), and not covered by health insurance (aOR, 0.74; 95% CI, 0.58–0.95) reduced the odds of self-reported HTN. On the other hand, being black/African (aOR, 1.73; 95% CI, 1.17–2.54), perception of being overweight (aOR, 1.72; 95% CI, 1.40–2.11), and perception of having poor health status (aOR, 3.53; 95% CI, 2.53–5.21) and the presence of other comorbidities (aOR, 7.92; 95% CI, 3.63–17.29) increased the odds of self-reported HTN. Conclusions: Self-reported HTN was largely associated with multiple sociodemographic, health, and lifestyle factors and the presence of other chronic conditions. Health promotion and services aiming at reducing the burden of HTN in South Africa should consider the associated factors reported in this study to ensure healthy aging and quality of life among women.
This study was approved by the South Africa Medical Research Council and the Institutional Review Board of International Classification of Functioning (ICF). All methods were conducted in accordance with the Declaration of Helsinki principles. The data were de-identified to prevent the respondents’ identity from being revealed. All individuals who agreed to take part in the survey were asked to provide either written or verbal consent for the interview. Particularly, verbal consent was sought from participants who could not write or read. The Centre for Disease Control and Prevention granted a waiver of written consent per 45CFR46 for respondents who were unable to provide written consent but consented verbally. The study used cross-sectional data from SADHS 2016. The SADHS 2016 was conducted to provide up-to-date estimates of basic demographic and measures of population health such as fertility levels, awareness and use of contraceptives, childhood and maternal mortality, immunization coverage, and prevalence and treatment of acute respiratory infection, fever, diarrhea, nutrition, etc. [29]. Additionally, the survey was also conducted to provide estimates of health and behavior measures for adults aged 15 years and older. The sample for the SADHS 2016 was designed to produce estimates of vital measures of the country as a whole: urban and nonurban areas. Administratively, South Africa is divided into nine provinces namely Eastern Cape, Free State, Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga, Northern Cape, North West, and Western Cape, which vary considerable in size. The Statistics South Africa Master Sample Frame was created using Census 2011 data. Enumeration areas (EAs) was used as the sampling frame for the SADHS 2016. In the Master Sample Frame, EAs of manageable size were treated as primary sampling units (PSUs), whereas small neighboring EAs were combined to form new PSUs, and large EAs were split into conceptual PSUs. Using a two-stage stratified sampling design with a probability proportional to size, PSUs were selected at the first stage while the systematic sampling of residential dwelling units (DUs) was performed at the second stage. Thus, a total of 750 PSUs were selected from the 26 sampling strata. From each PSU, a fixed number of 20 residential DUs were selected using a systematic sampling technique. Of the 15,292 households selected, 13,288 households were occupied, and interviews were successfully conducted in 83% of the occupied households. Data collection was conducted between June 2016 and November 2016 at the request of the National Department of Health. Data were collected using questionnaires administered by conducting face-to-face interviews. All households were eligible for interviews using the Household Questionnaire where basic demographic indicators on the characteristics of each person listed were collected, including age, sex, marital status, education, and relationship to the head of the household were collected. Further, information on characteristics of the household’s DU, such as the source of drinking water, type of sanitation facility, materials used for the floor, walls, and roof of the DU, and ownership of various durable goods were also collected. Secondly, the woman’s questionnaire was used to collect information from all eligible women aged 15 years and older on background characteristics such as age, education, media, exposure, etc. Additionally, the woman’s questionnaires also included a module on adult health where information on the use of tobacco, alcohol, consumption of fat, salt, sugar, fruit, and vegetables, health care-seeking behaviors, and self-reported prevalence of a variety of noncommunicable diseases including HTN were captured. The present study considered self-reported HTN (high blood pressure) as the dependent variable. Specifically, respondents were asked, “Has a medical doctor, nurse, or health professional told you that you have high blood pressure?” If the response was “yes” then respondents were classified as having self-rated HTN, and if the response was “no,” then the respondents were considered having no self-reported HTN. Independent variables of this study were selected after a review of the relevant literature and their availability in the SADHS 2016 dataset [11, 17, 31]. In total, 10 sociodemographic variables, seven health and lifestyle-related factors, and three other comorbidities of chronic diseases were included. Sociodemographic variables included the age of the respondents, education level, ethnicity, household wealth, marital status, employment status, exposure to mass media, place of residence, and geographical region. Lifestyle-related factors included self-reported body mass index (BMI) and perception of own health, type of fruits eaten yesterday, type of vegetables eaten yesterday, frequency of eating processed meat, frequency of eating fried foods, and sugar-sweetened drinks in the last 24 h. Other chronic diseases included comorbidities of self-reported HTN, comorbidities of self-reported diabetes, and comorbidities of self-reported hypercholesterolemia. These variables were categorized as follows: age of the respondents in years (20–24, 25–29, 30–34, 35–39, 40–44, 45–49, 50 + years), educational level (no education/primary, secondary, tertiary education), ethnicity (black/African, white, colored and other), household wealth (poorest, poorer, middle, richer, richest), marital status (never married, currently married, divorced/widowed), current employment (not employed or employed), covered by health insurance (yes or no), the amount of mass media exposure (0, 1, 2, 3), place of residence (urban or rural), and geographical region (Western Cape, Eastern Cape, Northern Cape, Free State, KwaZulu-Natal, North West, Gauteng, Mpumalanga, Limpopo). Household wealth was calculated using household items such as such as televisions and bicycles, materials used for housing construction, and types of water access and sanitation facilities and principal component analysis was used to create scores and these were further divided into quintiles. Health and lifestyle-related factors included perception of own weight—BMI (underweight, normal weight, overweight/obese), perception of own health, also known as self-rated health status (SRHS) was measured using a single question: “In general, how do would you rate your health?” with the following response options: excellent, good, moderate, or poor; type of fruits eaten yesterday (none, one type, two or more types); type of vegetables eaten yesterday (none, one type, two or more types); frequency of eating processed meat (never, every day, at least once a week, occasionally); frequency of eating fried foods (never, every day, at least once a week, occasionally); and sugar-sweetened drinks yesterday (no or yes). Objectively BMI is calculated by dividing the person’s weight in kilograms by their height in meters squared (kg/m2) [32]. For adults over 20 years old, BMI falls into one of the following categories: underweight (below 18.5 kg/m2), normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), and obesity (30 kg/m2 and above). Comorbidities for self-reported HTN included self-reported diabetes and self-reported hypercholesterolemia. Particularly, respondents were asked; “Has a medical doctor, nurse, or health provider told you that you have high blood pressure?” If the response was “yes” then respondents were classified as having self-reported diabetes/blood sugar or high blood cholesterol/fats in the blood (hypercholesterolemia), and if the response was “no”, then the respondents were considered having no self-reported diabetes or hypercholesterolemia. All data analyses were conducted using SAS ver. 9.4 (SAS Institute Inc., Cary, NC, USA). Characteristics of the study population were presented with numbers and percentages. Group comparisons between respondents that reported to have HTN and those that did not have HTN were made with Rao-Scott chi-square test. To assess the relationship between the selected variables and self-reported HTN, multivariate logistic analyses were constructed using a generalized estimating equation. The generalized estimating equation models accounted for the clustering effects of the hierarchical SADHS data. The results of the multivariate analysis were reported as adjusted odds ratios (aORs) with their P-values and 95% confidence intervals (CIs). A P-value of less than 0.05 was considered statistically significant.