Factors associated with poor adherence to medication among hypertensive patients in twelve low and middle income Sub-Saharan countries.

INTRODUCTION: Over the past few decades, the prevalence of hypertension has dramatically increased in Sub-Saharan Africa. Poor adherence has been identified as a major cause of failure to control hypertension. Scarce data are available in Africa. AIMS: We assessed adherence to medication and identified socioeconomics, clinical and treatment factors associated with low adherence among hypertensive patients in 12 sub-Saharan African countries. METHOD: We conducted a cross-sectional survey in urban clinics of both low and middle income countries. Data were collected by physicians on demographics, treatment and clinical data among hypertensive patients attending the clinics. Adherence was assessed by questionnaires completed by the patients. Factors associated with low adherence were investigated using logistic regression with a random effect on countries. RESULTS: There were 2198 individuals from 12 countries enrolled in the study. Overall, 678 (30.8%), 738 (33.6%), 782 (35.6%) participants had respectively low, medium and high adherence to antihypertensive medication. Multivariate analysis showed that the use of traditional medicine (OR: 2.28, 95%CI [1.79-2.90]) and individual wealth index (low vs. high wealth: OR: 1.86, 95%CI [1.35-2.56] and middle vs. high wealth: OR: 1.42, 95%CI [1.11-1.81]) were significantly and independently associated with poor adherence to medication. In stratified analysis, these differences in adherence to medication according to individual wealth index were observed in low-income countries (p<0.001) but not in middle-income countries (p = 0.17). In addition, 26.5% of the patients admitted having stopped their treatment due to financial reasons and this proportion was 4 fold higher in the lowest than highest wealth group (47.8% vs 11.4%) (p<0.001). CONCLUSION: This study revealed the high frequency of poor adherence in African patients and the associated factors. These findings should be useful for tailoring future programs to tackle hypertension in low income countries that are better adapted to patients, with a potential associated enhancement of their effectiveness.

Substandard drugs among five common antihypertensive generic medications: an analysis from 10 African countries.

OBJECTIVE: Hypertension results in more deaths than any other risk factor and has been on the rise in sub-Saharan Africa over the past few decades. Generic drugs have helped improve accessibility and affordability of antihypertensive therapy in developing countries. However, assessment of quality standards of these products is important. We performed a quality assessment of five commonly used antihypertensive generic drugs in 10 sub-Saharan African countries and studied the impact of price on quality. METHODS: Drug samples were prospectively collected using standardized methods between 2012 and 2014. We developed a validated reversed-phase liquid chromatography with tandem mass spectrometry method to accurately quantify the active ingredient in a certified public laboratory. Quality was defined based on the percentage ratio of measured to expected dosage of active ingredient. RESULTS: A total of 1185 samples were assessed, of which 70.0% were generic (n = 830). Among the generic drugs, the percentage of poor-quality drugs was 24.3% (n = 202/830). The percentage ratio of measured to expected dosage of active ingredient ranged from 49.2 to 111.3%; the majority (81.7%) of the poor-quality samples had insufficient quantity of the active ingredient. Moreover, poor quality was not associated with purchase price of the drug. CONCLUSION: In this study from 10 sub-Saharan African countries, nearly one-quarter of the available generic antihypertensive drugs were found to be of poor quality. Concerted measures to improve the quality of antihypertensive drugs could lead to major improvements in hypertension control with attendant reduction of its deleterious consequences in low-income and middle-income countries.