Onoja Matthew Akpa

College of Medicine, University of Ibadan · Epidemiology and Medical Statistics

Background: Every minute, six indigenous Africans develop new strokes. Patient-level and system-level contributors to early stroke fatality in this region are yet to be delineated. We aimed to identify and quantify the contributions of patient-level and system-level determinants of inpatient stroke fatality across 16 hospitals in Ghana and Nigeria...

Background Sub-Saharan Africa has the highest incidence, prevalence, and fatality from stroke globally. Yet, only little information about context-specific risk factors for prioritising interventions to reduce the stroke burden in sub-Saharan Africa is available. We aimed to identify and characterise the effect of the top modifiable risk factors fo...

Background Data on the burden and outcomes of recurrent strokes in sub-Saharan Africa are limited, impeding efforts at optimal recurrent stroke prevention. Objective To assess the prevalence, risk factor profile, stroke types and mortality from recurrent strokes in Ghana and Nigeria. Methods We analyzed data from 3553 stroke cases involved in the...

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This research was supported by the Brain Pool Program supported through the National Research Foundation of Korea, funded by the Ministry of Science and ICT (2020H1D3A1A04081265). Background Dyslipidemia is a prominent risk factor of m...

The Cardiometabolic Disorders in African-Ancestry Populations (CARDINAL) study site is a well-powered, first-of-its-kind resource for developing, refining and validating methods for research into polygenic risk scores that accounts for local ancestry, to improve risk prediction in diverse populations.

Africa is gradually becoming the epicentre for the burden of cardiovascular diseases (CVDs) worldwide, and community-based data alluding to the pattern and dynamics of escalating epidemiological thresholds of CVDs among indigenous Africans are limited. This manuscript focuses on the design and methods of Community-based Investigation of the Risk Fa...

Background: The relationship of diet with stroke risk among Africans is not well understood. Aim: To investigate the association between dietary patterns and stroke risk among West Africans. Methods: In this multi-centre case-control study, 3684 stroke patients matched (for age and sex) with 3684 healthy controls were recruited from Nigeria and Gha...

Background and Aim Illicit substance use (ISU) is a public health problem and a prominent risk factor to morbidity and mortality worldwide. However, whether ISU contributes significantly to the escalating burden of stroke in sub-Saharan Africa is yet to be clearly understood. This study assessed the relationship between ISU and the risk of stroke a...

Background & Aim Early identification and treatment of populations at risk of stroke in Africa have been delimited by the data to design a risk prediction model tailor-made for indigenous Africans. This study developed and tested an Afrocentric risk scoring model to predict stroke occurrence among West Africans. Method 7066 case-control pairs (ide...

Background and Aims Several studies have reported the relationship of diets to various diseases, but evidence for the true relationship between the consumption of green leafy vegetables and ischemic stroke (IS) or coronary artery diseases (CAD) is relatively limited. This study assessed the true association between higher consumption of green leafy...

Background The relationship between serum LDL level and hemorrhagic stroke is inconclusive. Several epidemiological Studies have noted that low LDL is a risk factor for ICH, however very few studies have defined the link between LDL and hemorrhagic stroke severity. Aim We hypothesized that low serum LDL levels may have association with intracerebr...

Transfusion transmissible infections (TTIs) such as Hepatitis B Virus (HBV), Hepatitis C Virus (HCV) and Human Immunodeficiency Virus (HIV) are among the most frequent complications in individuals with Sickle Cell Disease (SCD). We investigated factors associated with TTIs in SCD patients and controls in South-west Nigeria. A total of 2,034 partici...

Introduction: Second-hand smoking (SHS) is an emerging phenomenon in cardiovascular disease (CVD) epidemiology, but whether SHS is associated with stroke is not clearly understood. We assessed the association between SHS and stroke risk in a cohort of West Africans in the Stroke Investigative Research and Educational Network (SIREN) study. Hypothes...

Introduction: High blood pressure is a prominent risk factor for stroke in Sub-Saharan Africa (SSA) where dietary factors associated with blood pressure are often under-reported. Hypothesis: Dietary patterns (DP) are not associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) among stroke-free Africans from Ghana and Nigeri...

This study was designed to investigate the transmission dynamics of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to inform policy advisory vital for managing the spread of the virus in Nigeria. We applied the Susceptible-Exposed-Infectious-Recovered (SEIR)-type predictive model to discern the transmission dynamics of SARS-...

Background: Hepatitis B virus infection, a major public health problem that primarily affects the liver, may cause reduction in the levels of haemoglobin, haematocrit and in the extreme, could cause aplastic anaemia. The haematological characteristics could be detected with a complete blood count which could provide invaluable information for diag...

Background: Hepatitis B virus infection, a major public health problem that primarily affects the liver, may cause reduction in the levels of haemoglobin, haematocrit and in the extreme, could cause aplastic anaemia. The haematological characteristics could be detected with a complete blood count which could provide invaluable information for diagn...

Background Hypertension is a major public health problem and a prominent risk factor for cardiovascular diseases. However, whether passive smoking exposure (PSE) is associated with the risk of hypertension is scarcely understood. This study assessed the association between PSE and the risk of hypertension among adults (≥18 years) in the United Stat...

Objectives To explore the prevalence and risk factors of obesity among older adults from low- and middle-income countries (LMICs). Methods This is a secondary analysis of data obtained from the SIREN study through in-person interviews and measurements from healthy stroke-free older adults (≥60 years). Overweight/obesity was defined as body mass in...

Background Stroke risk can be quantified using risk factors whose effect sizes vary by geography and race. No stroke risk assessment tool exists to estimate aggregate stroke risk for indigenous African. Objectives To develop Afrocentric risk-scoring models for stroke occurrence. Materials and Methods We evaluated 3533 radiologically confirmed Wes...

Background and Purpose To identify the qualitative and quantitative contributions of conventional risk factors for occurrence of ischemic stroke and its key pathophysiologic subtypes among West Africans. Methods The SIREN (Stroke Investigative Research and Educational Network) is a multicenter, case-control study involving 15 sites in Ghana and Ni...

Background Depression is a psychological dysfunction that impairs health and quality of life. However, whether environmental tobacco smoke exposure (ETSE) is associated with depression is poorly understood. This study was designed to evaluate the association of ETSE with depression among non-smoking adults in the United States. Method Using the 20...

Despite projections of stroke being a leading cause of mortality in Africa, reliable estimates of stroke burden on the continent using rigorous methods are not available. We aimed to implement a mobile-Health community-based interactive Stroke Information and Surveillance System to sustainably measure stroke burden and improve stroke health literac...

Background This report describes the design and methodology of the “Eyes of Africa: The Genetics of Blindness,” a collaborative study funded through the Human Heredity and Health in Africa (H3Africa) program of the National Institute of Health. Methods This is a case control study that is collecting a large well phenotyped data set among glaucoma...

Background The burden of stroke in Africa is high. Understanding how age associates with major modifiable stroke risk factors could inform tailored demographic stroke prevention strategies. Purpose To quantify the magnitude and direction of the effect sizes of key modifiable stroke risk factors according to three age groups: <50 years (young), 50–6...

Dyslipidemia is a major public health challenge worldwide and whether secondhand smoke exposure (SHSE) is associated with dyslipidemia is yet to be understood. This study evaluated the relationship between SHSE and odds of dyslipidemia among adults in the United States. We identified 3064 adults who had never smoked in the 2015–2016 National Health...

Aim: Low- and middle-income countries (LMICs) are currently experiencing increasing cardiovascular disease (CVD) rates. Green leafy vegetables (GLV), which are abundant in these countries, are known to be particularly rich in cardioprotective nutrients. This study sought to determine the specific effect of GLV intake on the incidence of CVD. Meth...

Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Health (NIH) OnBehalf SIREN as part of the H3 Africa Consortium Background Hypertension is the principal risk factor for stroke events in Sub-Saharan Africa (SSA). However, international evidence on the significance of physical i...

Background and purpose The role of copy number variation (CNV) variation in stroke susceptibility and outcome has yet to be explored. The Copy Number Variation and Stroke (CaNVAS) Risk and Outcome study addresses this knowledge gap. Methods Over 24,500 well-phenotyped IS cases, including IS subtypes, and over 43,500 controls have been identified,...

Background: Age is a non-modifiable risk factor for stroke occurrence due its influence on vascular risk factor acquisition. In sub-Saharan Africa, the effect sizes of vascular risk factors for stroke occurrence by age is unknown. Objective: To quantify the magnitude and direction of the effect sizes of key modifiable risk factors of stroke accordi...

Hypertension is one of the most important risk factors for stroke and cardiovascular diseases (CVD) globally. Understanding risk factors for hypertension among individuals with matching characteristics with stroke patients may inform primordial/primary prevention of hypertension and stroke among them. This study identified the risk factors for hype...

Background Acute infections have been posited as potential precipitants or triggers of the occurrence of stroke among adults with traditional vascular risk factors. We evaluated associations between stroke occurrence and reported febrile illness within 4 weeks (potential antecedent infections) among West Africans. Methods The Stroke Investigative...

The burden of stroke and cardiovascular diseases (CVD) is increasing rapidly, especially in low and middle-income countries (LMIC). Most of the risk factors for these diseases are modifiable and influenced by lifestyle and diet. Although regular consumption of fruits and vegetables are often recommended, the evidence appears burly for green leafy v...

Objectives: Depression is a risk factor for stroke. There is a knowledge gap on the predictors of prestroke depression in stroke survivors living in low- and middle-income countries (LMICs). We estimated prevalence and predictors of prestroke depression, as well as its association with poststroke depression (PSD) in the largest study of stroke in A...

Introduction: The occurrence of hypertension in people living with human immunodeficiency virus/ acquired immunodeficiency syndrome (PLWHA) on antiretroviral therapy (ART) is increasing. In Nige-ria, where the national human immunodeficiency virus (HIV) prevalence is 1.4%, an estimated 700,000 PLWHA are on ART. We investigated the prevalence of hyp...

Background There is relatively limited information on the risk factors and outcome of new onset Poststroke Anxiety (PSA) in Low- and Middle-Income Countries. We estimated incidence, cumulative incidence, risk factors and outcome of new onset anxiety in the first year of stroke among African stroke survivors. Methods We analyzed the dataset of a co...

Green Infrastructure (GI) facilities have capacity to enhance health and mitigate Environmental Sustainability Challenges (ESC). However, the extent of the mitigation and health benefits is unclear in developing countries. This study examined the impact of GI on ESC and Perceived Health (PH) of urban residents in Lagos Metropolis, Nigeria. Multi-st...

Background: The Ibadan Low Back Pain Disability Questionnaire (ILBPDQ) was developed to meet the need for a LBP treatment outcome measure that was appropriate for the Nigerian culture and environment. The objective of this study was to determine the psychometric properties of ILBPDQ. Methods: This study used the validation design. One hundred an...

Recent decline in stroke mortality engendered by improved treatment has led to an increase in post-stroke morbidity and related healthcare cost. Most of post-stroke morbidity is due to depression. Few studies have examined the association of contextual factors with post-stroke depression (PSD) using a multilevel framework. This study used multileve...

Hypertension and obesity are the most important modifiable risk factors for cardiovascular diseases, but their association is not well characterized in Africa. We investigated regional patterns and association of obesity with hypertension among 30 044 continental Africans. We harmonized data on hypertension (defined as previous diagnosis/use of ant...

Background: Existing data from several reports on the association between lipid profile and ovarian tumour (OT) suggests divergent conclusions. Our aim was to examine whether circulating lipid profile: total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) differed between cases and non-cases of...

Environmental Attitude (EA) has been understood to be a complex multidimensional construct with minimal empirical evidence in developing countries. In the present study, psychometric properties of an EA scale was empirically assessed using data from a community based study conducted in Nigeria. Different measures of EA were aggregated into a single...

Objective To characterize risk factors for spontaneous intracerebral hemorrhage (sICH) occurrence and severity among West Africans. Methods The Stroke Investigative Research and Educational Network (SIREN) study is a multicenter case-control study involving 15 sites in Ghana and Nigeria. Patients were adults ≥18 years old with CT-confirmed sICH wi...

Background: There is paucity of data on the epidemiology of post-stroke cognitive impairment among African stroke survivors. The aim of this study is to report the profile and risk factors of post- stroke cognitive impairment among stroke survivors participating in the Stroke Investigative Research and Education Network (SIREN) Study. Methods: 1566...

Background: The risk factors associated with the occurrence of the distinct pathophysiologic subtypes of ischemic stroke are unknown among indigenous Africans. Objective: To identify and quantify the contributions of risk factors for occurrence of ischemic stroke and its etiologic subtypes among West Africans. Methods: The Stroke Investigative Rese...

Environmental Attitude (EA) has been understood to be a complex multidimensional construct with minimal empirical evidence in developing countries. In the present study, psychometric properties of an EA scale was empirically assessed using data from a community based study conducted in Nigeria. Different measures of EA were aggregated into a single...

Aim: To assess whether Substance Use (SU) is associated with Psychosocial Function (PF) among adolescent. Methods: Using a self-administered validated instrument, we obtained information on demographic, SU (defined as self-reported affirmative use of one or more of any form of alcoholic drinks, cigarettes, hemps etc) and PF [using the adolescent ps...

Background: Low Back Pain (LBP) is the leading cause of disability globally. Standardized outcome measures for measuring LBP disability exist but none was developed with consideration for the Nigerian culture and environment. Objective: This study was aimed to develop a Nigerian culture- and environment-friendly LBP scale, the Ibadan Low Back Pa...

Background Little is known about the relationship between echocardiographic abnormalities and outcome among patients with acute stroke. We investigated the pattern and association of baseline echocardiographic variables with 1‐month disability and mortality among patients with stroke in the SIREN (Stroke Investigative Research and Education Network...

Background and Purpose— The interplay between sex and the dominant risk factors for stroke occurrence in sub-Saharan Africa has not been clearly delineated. We compared the effect sizes of risk factors of stroke by sex among West Africans. Methods— SIREN study (Stroke Investigative Research and Educational Networks) is a case-control study conduct...

Introduction Intimate Partner Violence (IPV) is an under-reported public health problem. This study determined the prevalence of IPV and types of IPV, complications and factors associated with IPV among women accessing health services. Methods we conducted a cross-sectional survey of 702 women accessing maternal and child health services in Enugu...

Apart from proximate determinants, certain sociodemographic factors have been reported to inform fertility in some developing nations but a comprehensive report for Nigeria is lacking in the literature. This study tested effects of some determinants of fertility on the level of fertility in Nigeria using data from the 2008 Nigerian Demographic Heal...

Background: It is crucial to assess genomic literacy related to stroke among Africans in preparation for the ethical, legal and societal implications of the genetic revolution which has begun in Africa. Objective: To assess the knowledge, attitudes and practices (KAP) of West Africans about stroke genetic studies. Methods: A comparative cross-secti...

Background: It is crucial to assess genomic literacy related to stroke among Africans in preparation for the ethical, legal and societal implications of the genetic revolution which has begun in Africa. Objective: To assess the knowledge, attitudes and practices (KAP) of West Africans about stroke genetic studies. Methods: A comparative cross-...

Objective Primary language has been reported to influence the results of neuropsychological (NP) testing. We sought to determine whether being a primary Spanish versus English speaker affects changes in neuropsychological evaluations in persons living with HIV. Method Data from 209 (188 English speakers and 21 Spanish speakers) ART‐naïve HIV‐infec...

Africa was previously insufficiently represented in the emerging discipline of biobanking despite commendable early efforts. However, with the Human, Heredity, and Health in Africa (H3Africa) initiative, biorepository science has been bolstered, regional biobanks are springing up, and awareness about biobanks is growing on the continent. The Stroke...

Psychosocial functioning is increasing a public health priority issue among young people. Previous reports have focused on the effect of personal health conditions on the psychosocial well-being of children but contextual analysis of environmental or social factors could provide relevant information for interventions. In the context of HIV/AIDS, th...

Background and purpose: Stroke in lower and middle-income countries affects a young and productive age group. Data on factors associated with stroke in the young are sorely lacking from lower and middle-income countries. Our objective is to characterize the nature of stroke and its risk factors among young West Africans aged <50 years old. Method...

Background Childhood and adolescent depression is common and often persists into adulthood with negative implications for school performances, peer relationship and behavioural functioning. The Child Depression Inventory (CDI) has been used to assess depression among adolescents in many countries including Nigeria but it is uncertain if the theoret...

Abstract Background: Sub-Saharan Africa has the highest incidence, prevalence, and fatality from stroke globally. Yet, only little information about context-specific risk factors for prioritising interventions to reduce the stroke burden in sub-Saharan Africa is available. We aimed to identify and characterise the effect of the top modifiable risk...

Background: Sub-Saharan Africa has the highest incidence, prevalence, and fatality from stroke globally. Yet, only little information about context-specific risk factors for prioritising interventions to reduce the stroke burden in sub-Saharan Africa is available. We aimed to identify and characterise the effect of the top modifiable risk factors...

Poor adherence to hypertension treatment is a major health-related problem, and a significant risk factor for complications, disability and hypertension associated mortality. There is a paucity of evidence on the impact of treatment satisfaction on medication adherence among hypertensive patients in Nigeria. This study aimed to determine the associ...

Background: Compared with High-Income Countries, stroke in low and middle income countries affects a young and productive age group. Yet, data on risk factors and phenotypic characteristics of stroke in the young are sorely lacking from these regions severely challenging efforts at stroke prevention. Objective: To identify and quantify the unique t...

Accurate epidemiological surveillance of the burden of stroke is direly needed to facilitate the development and evaluation of effective interventions in Africa. The authors therefore conducted a systematic review of the methodology of stroke epidemiological studies conducted in Africa from 1970 to 2017 using gold standard criteria obtained from la...

Introduction: The World Health Organization's Quality of Life Instrument (WHOQOL-BREF) is widely validated and popularly used in assessing perceived quality of life (QOL) of adolescents and the general population. Though the WHOQOL-BREF has been used in some studies in Nigeria, its theoretical structure has not been comprehensively investigated. T...

Objective: Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including th...