Abstract
Background
High Blood Pressure is the worldwide leading global burden of disease risk factor. In Sub-Saharan Africa, the number of adults with raised blood pressure has alarmingly increased from 0.59 to 1.13 billion between 1975 and 2015. Blood pressure-lowering medicines are cornerstone of cardiovascular risk reduction. Data on management of anti-hypertensive drugs in sub-Saharan Africa are squarce.
Purpose
Our study aims to describe antihypertensive drugs strategies in Africa.
Methods
We conducted a cross-sectional survey in urban clinics during outpatient consultation specialized in hypertension cardiology departments of 29 medical centers from 17 cities across 12 African countries (Benin, Cameroon, Congo, Democratic Republic of Congo, Gabon, Guinea, Ivory Coast, Mauritania, Mozambic, Niger, Senegal, Togo). Data were collected on demographics, treatment and standardized BP measures were made among the hypertensive patients attending the clinics. Country income was retrieved from the World Bank database. All analyses were performed through scripts developed in the R software (3.4.1 (2017–06–30)).
Results
A total of 2198 hypertensive patients (58.4±11.8 years; 39.9% male) were included. Among whom 2123 (96.6%) had at least one antihypertensive drug. Overall, 30.8% (n=653) received monotherapy and calcium-channel blockers (49.6%) were the most common monotherapy prescribed follow by diuretics (18.7%). Two-drug strategies were prescribed for 927 patients (43.6%). Diuretics and Angiotensin-converting enzyme inhibitors was the combination most frequently prescribed (33.7%). Combination of three drugs or more was used in 25.6% (n=543) of patients. The proportion of drugs strategies differed significantly according to countries (p<0.001), monotherapy ranged from 12.7% in Niger to 47.1% in Democratic Republic of the Congo (figure). Furthermore we observed a significantly difference of strategies between low and middle income countries (55.3% and 44.7% of monotherapy respectively) (p<0.001). According to hypertension grades 1, 2 and 3, the proportion of three-drugs or more combination was 25%, 28% and 34% in middle-income and lower in low-income countries (18%, 19% and 25%). Furthermore, Grade 3 hypertension in low income countries was still treated with monotherapy (36%) instead of 19% in middle income countries (p<0.01).
Antihypertensive strategies by country
Conclusion
Our study described antihypertensive drugs use across 12 sub-Saharan countries, and identified disparities specific to the income context. Inequity in access to drugs combination is a serious barrier to tackle the burden of hypertension in Africa.