Prevalence, awareness, treatment, and control of hypertension in Cameroonians aged 50 years and older: A community‐based study

Abstract Aims To assess the prevalence of hypertension (HTN) in a rural elderly population (50 y and older) in Cameroon; evaluate the rates of awareness, treatment, and control of HTN in this population; and describe factors associated with HTN in this population. Methods and Results A total of 501 participants aged 50 years and older were randomly recruited from May to July 2013 in a house‐to‐house survey of the Batibo Health District. Data were measured using standardized methods modelled after the World Health Organization STEPwise approach to Surveillance. The Statistical Package for the Social Sciences version 20.0 was used for statistical analysis. Chi‐square, Fisher's exact or Student T test were used to compare variables. A multivariable logistic regression analysis was used to identify factors associated with HTN in this population. In our study population, 31% of the participants were men, with a mean age of 65.4 ± 8 years; women had a mean age of 61.4 ± 9 years. The prevalence of HTN was 57.3% (95% CI, 52.9‐61.6). The awareness rate was 63.4%, treatment rate 96.7%, and control rate 32.4%. Being overweight/obese was independently associated with HTN in this group (odds ratio = 3.46; 95% CI, 2.38‐5.03; P < .001). Conclusion The prevalence of HTN amongst the elderly in the Batibo Health District is high. Emphasis should be on patient education to improve the rates of blood pressure control amongst patients on treatment for HTN. Healthy lifestyle measures such as reduction in salt intake and increase in physical exercise should be encouraged amongst the elderly.


| Study setting and duration
This was a community-based, cross-sectional and analytic study per-

| Study population and sampling
Eligible participants aged 50 years and older were recruited from each health area using a simple random sampling technique. Participants who refused to sign an informed consent form or provide a verbal consent were excluded from the study.
Sample size was determined using the following formula: where n is the sample size (number of elderly participants), P is the expected prevalence of HTN in an elderly population (P = .58), 15 and d is the precision (if 5%, d = 0.05). Z statistics (Z): For the level of confidence of 95%, which is conventional, Z value is 1.96 for a 95% CI.
A minimum of 375 elderly participants were required for this study.

| Ethical considerations
Ethical approval to conduct the study was obtained from the Institutional Review Board of the Faculty of Health Sciences, University of Buea, Cameroon. Apart from the inconvenience of taking time to answer the research questionnaire, participants were not exposed to any undue risk. The participants had their BPs measured for free, and they received free advice on lifestyle modifications to prevent or treat HTN. A translator was used for participants who did not understand English, French, or the local lingua franca. All participants provided a verbal consent to participate in the study.

| RESULTS
In total, 501 individuals participated in this study, 68.8% of whom were women. Table 1  were on treatment and 57 (32.4%) had a controlled BP ( Figure 1).   (72.4%), 28 and South Africa (77.9%) 15 and the 74.1% to 89% prevalence in high-income countries. 29,30 These differences could be due to heterogeneity in sampling methods and cut-off age for the elderly population, ranging from 35 to 74 years across various studies. 1,15,26,27,[30][31][32][33] Compared with younger adults, older individuals are at least twice more likely to develop HTN. 33  After a multivariable logistic regression analysis, being overweight/ obese was the only factor that was independently associated with HTN in our study population. This is in line with findings in Central Africa, 39 Costa Rica, 40 Senegal, 27 and other LMICs. 15 The association between HTN and overweight/obesity is well-recognized and has been described by several authors, 15,33,41-43 even though the exact mechanism behind the relationship is poorly understood. Complex interactions between metabolic and neurohormonal pathways, with resultant alterations in insulin resistance, the renin-angiotensin-aldosterone system, and sympathetic tone, could explain the occurrence of HTN amongst people who are overweight/obese. [44][45][46][47][48][49] The awareness and treatment rates of 63.4% and 96.7% in our study are similar to the 62.4% and 93.3% rates in Pakistan, and the 69% and 90.8% rates in Peru, reported in a review of HTN in a slightly younger population in 9 LMIC by Irazola et al. 31 Our awareness rates were higher than the 44.6% 22 and 44.9% 23 found in the elderly in Mexico and India, respectively, and the 48.3% 15 found by the WHO's Study on Global Aging and Adult Health across LMICs. The value was lower than rates reported in high-income countries. 30,32 Our control rates were significantly lower than the 46% and 71% obtained in Pakistan and Peru, respectively, in a review of HTN in a slightly younger population in 9 LMIC by Irazola et al. 31 Our rates were considerably higher than those found in an elderly population in other LMICs. 15 increasing fruit and vegetable intake, and encouraging physical exercise. 50 In addition, home BP monitoring has been suggested as a potential strategy to improve treatment compliance and, consequently, optimal BP control. 53 Hence, home BP monitoring could serve as a valuable tool in reducing the burden of HTN in LMICs. 53,54 In response to the rising burden of HTN in Cameroon, the Ministry of Public Health developed the "national strategy for hypertension and diabetes control" and the "development of training and task-shifting programmes to improve detection and management at the primary care level." 19,[55][56][57] The aim was to promote equitable access to quality health services in order to reduce the morbidity and mortality associated with this condition. 7,58 Nonetheless, these programmes remain effective mainly at the tertiary levels, with very few of such programmes existing at the primary care level. From our experience, the success of such programmes at the primary care level often relies on the creativity and interest of the local health authorities in addressing these concerns.
From this study, we argue that initiatives such as free consultation days for the elderly could improve detection of HTN in primary care settings, and the creation of a HTN clinic could facilitate their follow-up and improve treatment and control rates. We recommend that such initiatives be implemented throughout the national territory to provide a lasting solution to the rising HTN burden.

| Study limitations
The findings from this study should be interpreted considering its limitations. The study was cross-sectional, meaning HTN was defined after measurements from a single encounter. Hypertension should