Data on the epidemiology of heart failure in Sub-Saharan Africa

In Sub-Saharan Africa (SSA), chronic non-communicable diseases and cardiovascular diseases in particular, are progressively taking over infectious diseases as the leading cause of morbidity and mortality. Heart failure is a major public health problem in the region. We summarize here available data on the prevalence, aetiologies, treatment, rates and predictors of mortality due to heart failure in SSA.


Specifications
Value of the data -This work provides a deeper understanding of the prevalence, etiologies and prognosis of heart failure in SSA. -The data allow examination of the different medications used for the treatment of heart failure and therefore could help in changing practices for an optimal management of this pathology. -The data could be used as a baseline for comparison in future studies.

Data
In SSA, heart failure is a major public health problem, associated with high morbidity and mortality. Due to the shortage of data to distinctly understand the epidemiology of this pathology in this part of the world, we present here a summary of available data on the prevalence, aetiology, treatment, and prognosis of heart failure in SSA.

Experimental design, materials, and methods
Through a systematic literature search in MEDLINE and EMBASE (search strategies are presented in Tables 1 and 2), we included all published studies from January 1, 1996 to June 23, 2017 with available data on the prevalence, incidence, aetiologies, diagnosis, treatment and outcomes of heart failure in patients aged 12 years and older, living in SSA. We excluded studies conducted exclusively on African populations living outside Africa, commentaries, editorials, letters to the editor, case reports and case-series of less than 30 participants, studies lacking relevant data to compute the prevalence of the different heart failure aetiologies or treatment, and for duplicate studies, the most comprehensive and/or recent study with the largest sample size was considered, studies with inaccessible full-text, even after request from the corresponding author.
The titles and abstracts of articles retrieved from the bibliographic searches were independently screened by two investigators and full-texts of potentially eligible studies were retrieved and assessed for final inclusion. All discrepancies the selection of studies were resolved through discussion or with the arbitrage of a third investigator. A total of 35 studies were included in this review . A summary of the selection process is presented in the Fig. 1.
Data were then extracted using a predesigned data extraction form. The extracted data include: the last name of first author and the year of study publication, the country in which the study was conducted, Region (Western, Southern, Central, Eastern), area (urban, semi-urban or rural), study design (cross-sectional, cohort, case control), data collection (prospective versus retrospective), random sampling (yes versus no), study population, male proportion, mean or median age (in years), age range (in years), sample size, criteria used for the diagnosis of heart failure, number of cases of the different aetiologies of heart failure and number of cases of the different medications used for the treatment of heart failure.
The quality and risk of bias of all included studies are presented in Tables 3-7. It was assessed using the risk of bias assessment tool for developed by Hoy et al. [36]. This tool was adapted for the different topics on heart failure covered in this review (prevalence, aetiology, treatment and prognosis of heart failure).
Data were analyzed using the 'meta' package of R software. A random-effects meta-analysis model was used to pool prevalence estimates after stabilization of the variance of the study-specific prevalence using the Freeman-Tukey single arc-sine transformation [37]. The Egger's test was used to assess publication bias which was considered significant if the p-value o 0.1. Summary statistics from meta-analyses of prevalence studies on the medications used to treat heart failure in sub-Saharan Africa are presented in Table 8.
These data are attached to a systematic review and meta-analysis published in the International Journal of Cardiology [38].          Table 7 Summary of studies reporting on the mortality rate and/or predictors of mortality among heart failure patients in sub-Saharan Africa.