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Advanced Neurology Stroke care in sub-Sahara Africa

3.1. Stroke incidence and prevalence in SSA and geographical region. Population-based prospective

Several studies suggest an increasing trend in stroke studies show a crude stroke mortality rate of 114/100,000
25
incidence, prevalence, and mortality rates in SSA, person-years. Stroke-related deaths as a proportion of
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although with significant variations. Between 1973 and overall mortality are approximately 5.5%, with 28-day and
27
1991, crude stroke incidence ranged from a minimum 3-year case fatality rates of 26.9% and 75.4%, respectively.
of 26 to a maximum of 101 (average 53) cases/100,000 Multiple hospital- and community-based studies show
population, based on findings from two hospital-based 28- to 30-day case fatality rates ranging from 4.0% to 49.6%
5,6,8,9,10,28
5
and one community-based studies from Nigeria, South (Table 1). A comprehensive systematic review and
Africa, and Zimbabwe. This finding contrasts with meta-analysis of 30-day, 1-year, 3-year, and 5-year stroke
7
6
studies conducted between 2003 and 2011, where the case fatality, including 91 studies with a total of 34,362
crude incidence of stroke from five different studies stroke cases from 18 SSA countries (Nigeria contributing
ranged from a minimum of 25 to a maximum of 149 33.3% and Cameroon 9.9% of the total studies), reported
(average 88) cases/100,000 population. 8-11 A similar trend pooled 30-day, 1-year, 3-year, and 5-year stroke case fatality
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in increasing stroke prevalence has been observed in rates of 24.1%, 33.2%, 40.1%, and 39.4%, respectively.
studies conducted between 1983 and 2000, indicating a However, these studies were highly heterogeneous,
prevalence rate ranging from 15 (low) to 243 (high), with encompassing cross-sectional, case-controlled, cohort,
an average of 111/100,000 population, 12-15 compared to the and other study designs, with only 9.9% classified as high-
period between 2008 and 2016, where prevalence ranged quality and 64.8% as average-quality studies.
from as low as 163 to as high as 2,300, with an average Predictors of stroke mortality in multiple studies
of 913/100,000 population. 16-22 A meta-analysis of 9 consistently show a higher risk of death among those
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population-based and two hospital-based studies between with hemorrhagic stroke. Other predictors of mortality
1995 and 2016 in Nigeria showed similar rising incidence identified include female gender, National Institute
rates of 24/100,000 population between 2000 and 2009 to of Stroke Scale score at presentation, anemia, human
27/100,000 population from 2010 onward, with a prevalent immunodeficiency virus (HIV) infection, pneumonia
rate of 670/100,000 population between 2000 and 2009 infection complicating hospital stay, hypertension,
increasing to 750/100,000 population from 2010 onward. 23 hyperglycemia, delayed stroke recognition, and inability to
It is important to note that studies of incidence or access early post-stroke care. 28-32
prevalence rates are often affected by study methodology. However, caution is warranted in interpreting mortality
Analysis limited to hospital cases can be fraught with rates reported in most of these studies. Most population-
challenges such as referral bias or selection bias due to based mortality and case fatality results were based
study subjects not being representative of the general stroke on verbal autopsies due to low levels of standardized
population. This bias can often lead to lower estimates in death registration in many SSA countries. Despite these
hospital-based studies. Indeed, a 2009 meta-analysis of shortcomings, however, these studies portray the high
19 original population-based and hospital-based studies burden of stroke mortality in SSA.
from 10 African countries showed that the pooled crude
incidence rate of stroke from community-based studies 3.3. Stroke risk factors
was higher at 113 as compared to 77/100,000 population Optimal primary and secondary stroke prevention requires
for hospital-based studies. Variation in reported incidence a comprehensive understanding of global, regional, and
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and prevalence rates is also affected by differences in case country-specific stroke risk factors to prioritize resources
definition, case ascertainment methods, study duration, for those at the greatest risk of major adverse endpoints. It
follow-up time, study period, and data point acquisition is worth emphasizing that prevention strategies may vary
methods (prospective versus retrospective). As an illustrative between high-income and low-income countries owing
example, community-based door-to-door survey prevalence to disparities in health-care access, available technologies,
studies may have more data points for stroke survivors due to relative stroke risk factors, and population lifestyles
the relative ease of identifying cases. Therefore, interpretation and culture. According to the 2016 Global Burden of
and comparison of studies require caution. Disease Study, the estimated global risk of stroke from
age 25 years onward in 1990 showed a relative increase
3.2. Mortality rate and its predictors among stroke of 8.9% compared to 2016. Countries in the high-middle
patients in SSA sociodemographic index had the highest risk at 31%

Mortality attributed to stroke is high in SSA, though with compared to low sociodemographic index countries at
significant variability depending on study methodology 13%. In SSA, a significant increase in the western and

Volume 3 Issue 2 (2024) 4 doi: 10.36922/an.2804