Non-cigarette Tobacco Use and Stroke Among West Africans: Evidence From the SIREN Study

INTRODUCTION

Non-cigarette tobacco (NCT) represents a form of tobacco use with a misperceived significance in chronic disease events. Whether NCT use is sufficient to promote stroke events, especially among Africans, is yet to be understood. This study assessed the relationship between NCT use and stroke among indigenous Africans.

METHODS

A total of 7617 respondents (NCT users: 41 vs. non-NCT: 7576) from the Stroke Investigative Research and Educational Network (SIREN) study were included in the current analysis. NCT use was defined as self-reported use of smoked (cigars or piper) or smokeless (snuff or chewed) tobacco in the past year preceding stroke events. Stroke was defined based on clinical presentation and confirmed with a cranial computed tomography/magnetic resonance imaging. Multivariable-adjusted logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the relationship of NCT with stroke at a two-sided p < .05.

RESULTS

Out of the 41 (0.54%) who reported NCT use, 27 (65.9%) reported using smokeless NCT. NCT users were older than non-NCT users (62.8 ± 15.7 vs. 57.7 ± 14.8 years). Overall, NCT use was associated with first-ever stroke (OR: 2.08; 95% CI: 1.02, 4.23) in the entire sample. Notably, smokeless NCT use was independently associated with higher odds of stroke (OR: 2.74; 95% CI: 1.15, 6.54), but smoked NCT use (OR: 0.16; 95% CI: 0.02, 1.63) presented a statistically insignificant association after adjusting for hypertension and other covariates.

CONCLUSIONS

NCT use was associated with higher odds of stroke, and public health interventions targeting NCT use might be promising in reducing the burden of stroke among indigenous Africans.

IMPLICATIONS

A detailed understanding of the relationship between NCT use and stroke will likely inform well-articulated policy guidance and evidence-based recommendations for public health prevention and management of stroke on the African continent.

Capacity-Building for Stroke Genomic Research Data Collection: The African Neurobiobank Ethical, Legal, and Social Implications Project Experience

Background: The fields of stroke genomics, biobanking, and precision medicine are rapidly expanding in sub-Saharan Africa. However, the ethical, legal, and social implications (ELSI) of emerging neurobiobanking and genomic data resources are unclear in an emerging African scientific landscape with unique cultural, linguistic, and belief systems. Objective: This article documents capacity-building experiences of researchers during the development, pretesting, and validation of data collection instruments of the African Neurobiobank for Precision Stroke Medicine-(ELSI) Project. Methods: The African Neurobiobank for Precision Stroke Medicine-ELSI project is a transnational, multicenter project implemented across seven sites in Ghana and Nigeria. Guided by the Community-Based Participatory Research framework, we conducted three workshops with key stakeholders to review the study protocol, ensure uniformity in implementation; pretest, harmonize, and integrate context-specific feedback to ensure validity and adaptability of data collection instruments. Workshop impact was assessed using an open-ended questionnaire, which included questions on experience with participation in any of the workshops, building capacity in Genetic and Genomic Research (GGR), level of preparedness toward GGR, the genomic mini-dictionary developed by the team, and its impact in enhancing understanding in GGR. Data were analyzed qualitatively using a thematic framework approach. Results: Findings revealed the usefulness of the workshop in improving participants' knowledge and capacity toward GGR implementation. It further identified local, context-specific concerns regarding quality data collection, the need to develop culturally acceptable, genomic/biobanking data collection tools, and a mini-dictionary. Participants-reported perceptions were that the mini-dictionary enhanced understanding, participation, and data collection in GGR. Overall, participants reported increased preparedness and interest in participating in GGR. Conclusion: Capacity-building is a necessary step toward ELSI-related genomic research implementation in African countries where scholarship of ELSI of genomics research is emerging. Our findings may be useful to the design and implementation of ELSI-GGR projects in other African countries.

Patient-level and system-level determinants of stroke fatality across 16 large hospitals in Ghana and Nigeria: a prospective cohort study

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.

METHODS

The Stroke Investigative Research and Educational Network (SIREN) is a multicentre study involving 16 sites in Ghana and Nigeria. Cases include adults (aged ≥18 years) with clinical and radiological evidence of an acute stroke. Data on stroke services and resources available at each study site were collected and analysed as system-level factors. A host of demographic and clinical variables of cases were analysed as patient-level factors. A mixed effect log-binomial model including both patient-level and system-level covariates was fitted. Results are presented as adjusted risk ratios (aRRs) with respective 95% CIs.

FINDINGS

Overall, 814 (21·8%) of the 3739 patients admitted with stroke died as inpatients: 476 (18·1%) of 2635 with ischaemic stroke and 338 (30·6%) of 1104 with intracerebral haemorrhage. The variability in the odds of stroke fatality that could be attributed to the system-level factors across study sites assessed using model intracluster correlation coefficient was substantial at 7·3% (above a 5% threshold). Stroke units were available at only five of 16 centres. The aRRs of six patient-level factors associated with stroke fatality were: low vegetable consumption, 1·19 (95% CI 1·07-1·33); systolic blood pressure, 1·02 (1·01-1·04) for each 10 mm Hg rise; stroke lesion volume more than 30 cm3, 1·48 (1·22-1·79); National Institutes of Health Stroke Scale (NIHSS) score, 1·20 (1·13-1·26) for each 5-unit rise; elevated intracranial pressure, 1·75 (1·31-2·33); and aspiration pneumonia, 1·79 (1·16-2·77).

INTERPRETATION

Studies are needed to assess the efficacy of interventions targeting patient-level factors such as aspiration pneumonia in reducing acute stroke fatality in this region. Policy directives to improve stroke unit access are warranted.

FUNDING

US National Institutes of Health.

TRANSLATIONS

For the Twi, Yoruba and Hausa translations of the abstract see Supplementary Materials section.

Stroke Learning Health Systems: A Topical Narrative Review With Case Examples

To our knowledge, the adoption of Learning Health System (LHS) concepts or approaches for improving stroke care, patient outcomes, and value have not previously been summarized. This topical review provides a summary of the published evidence about LHSs applied to stroke, and case examples applied to different aspects of stroke care from high and low-to-middle income countries. Our attempt to systematically identify the relevant literature and obtain real-world examples demonstrated the dissemination gaps, the lack of learning and action for many of the related LHS concepts across the continuum of care but also elucidated the opportunity for continued dialogue on how to study and scale LHS advances. In the field of stroke, we found only a few published examples of LHSs and health systems globally implementing some selected LHS concepts, but the term is not common. A major barrier to identifying relevant LHS examples in stroke may be the lack of an agreed taxonomy or terminology for classification. We acknowledge that health service delivery settings that leverage many of the LHS concepts do so operationally and the lessons learned are not shared in peer-reviewed literature. It is likely that this topical review will further stimulate the stroke community to disseminate related activities and use keywords such as learning health system so that the evidence base can be more readily identified.

Sociodemographic and behavioural risk factors for obesity among community-dwelling older adults in Ghana and Nigeria: A secondary analysis of data from the SIREN study

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 index ≥25 kg/m². Abdominal obesity was defined as waist-to-hip ratio (WHR) of >0.90 for males and >0.85/females or waist circumference (WC) of >102 cm for males/>88 cm for females. Adjusted odds ratio (aORs) with 95% confidence interval (CIs) of the relationship between obesity and sociodemographic factors were assessed at P < 0.05.

RESULTS

Overall, 47.5% of participants were overweight/obese, 76.6% had a larger than recommended WHR, and 54.4% had a larger than recommended WC. Abdominal obesity (WC; aOR: 9.43, CI: 6.99-12.50), being a Nigerian (aOR: 0.55; CI: 0.42-0.72), living in an urban setting (aOR: 1.92; CI: 1.49-2.46), earning >$100/month (aOR: 1.53; CI: 1.19-1.96), and having formal education (aOR: 1.42; CI: 1.08-1.87) were associated with overweight/obesity.

CONCLUSION

Living in urban settings, earning a higher income, and having a formal education were associated with a higher odds of obesity among older adults from LMICs.

Secondhand smoke exposure is independently associated with stroke among non-smoking adults in West Africa

BACKGROUND

Stroke is a leading cause of disability and mortality worldwide, but little is known about the contribution of secondhand smoke exposure (SHSE) to stroke epidemiology among indigenous Africans.

OBJECTIVE

To evaluate the association of SHSE with stroke among indigenous Africans.

METHODS

We analyzed the relationship of SHSE with stroke among 2990 case-control pairs of adults who had never smoked (identified in the SIREN study) using conditional logistic regression at a two-sided P < 0.05.

RESULTS

Multivariable-adjusted odds ratio and 95% confidence interval; 1.25 (1.04, 1.50; P = 0.02) revealed SHSE was positively associated with stroke independent of stroke subtypes.

CONCLUSION

Culturally relevant primary prevention strategies targeted at SHSE might be promising in preventing stroke among Africans.

Risk Factor Characterization of Ischemic Stroke Subtypes Among West Africans

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 Nigeria. Cases include adults aged ≥18 years with ischemic stroke who were etiologically subtyped using the A-S-C-O-D classification into atherosclerosis, small-vessel occlusion, cardiac pathology, other causes, and dissection. Controls were age- and gender-matched stroke-free adults. Detailed evaluations for vascular, lifestyle, and psychosocial factors were performed. We used conditional logistic regression to estimate adjusted odds ratios with 95% CI.

RESULTS

There were 2431 ischemic stroke case and stroke-free control pairs with respective mean ages of 62.2±14.0 versus 60.9±13.7 years. There were 1024 (42.1%) small vessel occlusions, 427 (17.6%) large-artery atherosclerosis, 258 (10.6%) cardio-embolic, 3 (0.1%) carotid dissections, and 719 (29.6%) undetermined/other causes. The adjusted odds ratio (95% CI) for the 8 dominant risk factors for ischemic stroke were hypertension, 10.34 (6.91-15.45); dyslipidemia, 5.16 (3.78-7.03); diabetes, 3.44 (2.60-4.56); low green vegetable consumption, 1.89 (1.45-2.46); red meat consumption, 1.89 (1.45-2.46); cardiac disease, 1.88 (1.22-2.90); monthly income $100 or more, 1.72 (1.24-2.39); and psychosocial stress, 1.62 (1.18-2.21). Hypertension, dyslipidemia, diabetes were confluent factors shared by small-vessel, large-vessel and cardio-embolic subtypes. Stroke cases and stroke-free controls had a mean of 5.3±1.5 versus 3.2±1.0 adverse cardio-metabolic risk factors respectively (P<0.0001).

CONCLUSIONS

Traditional vascular risk factors demonstrate important differential effect sizes with pathophysiologic, clinical and preventative implications on the occurrence of ischemic stroke among indigenous West Africans.

A Novel Afrocentric Stroke Risk Assessment Score: Models from the Siren Study

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 West African stroke cases paired 1:1 with age-, and sex-matched stroke-free controls in the SIREN study. The 7,066 subjects were randomly split into a training and testing set at the ratio of 85:15. Conditional logistic regression models were constructed by including 17 putative factors linked to stroke occurrence using the training set. Significant risk factors were assigned constant and standardized statistical weights based on regression coefficients (β) to develop an additive risk scoring system on a scale of 0-100%. Using the testing set, Receiver Operating Characteristics (ROC) curves were constructed to obtain a total score to serve as cut-off to discriminate between cases and controls. We calculated sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) at this cut-off.

RESULTS

For stroke occurrence, we identified 15 traditional vascular factors. Cohen's kappa for validity was maximal at a total risk score of 56% using both statistical weighting approaches to risk quantification and in both datasets. The risk score had a predictive accuracy of 76% (95%CI: 74-79%), sensitivity of 80.3%, specificity of 63.0%, PPV of 68.5% and NPV of 76.2% in the test dataset. For ischemic strokes, 12 risk factors had predictive accuracy of 78% (95%CI: 74-81%). For hemorrhagic strokes, 7 factors had a predictive accuracy of 79% (95%CI: 73-84%).

CONCLUSIONS

The SIREN models quantify aggregate stroke risk in indigenous West Africans with good accuracy. Prospective studies are needed to validate this instrument for stroke prevention.

Sexual Abuse among Female Adolescent Hawkers in Selected Markets in Ibadan, Nigeria

Involvement of a child or adolescent in a sexual activity is a global public health challenge. This cross-sectional study documented experiences of sexual abuse (SA) among Female Adolescent Hawkers (FAHs) in selected markets in Ibadan, Nigeria. Data were collected from 410 FAHs using interviewer-administered questionnaire. Descriptive statistics, chi-square and logistic regression were used to analyze the data at p < .05 significance level. Mean age of respondents was 14.4 ± 1.76 years. The majority (69.0%) have ever experienced at least a form of SA, of which 68.3% occurred 3 months preceding the study. Having had sex and boyfriends were predictors of SA. Male customers (98.6%), traders (98.2%) and peers (69.4%) were major perpetrators. About 67.5% of victims of SA did not seek help. Sexual abuse is a major problem among FAHs. Age-appropriate sexuality education and life-building skills interventions should be targeted at FAHs while advocacy is recommended for caregivers and market stakeholders.

Factors associated with hypertension among stroke-free indigenous Africans: Findings from the SIREN study

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 hypertension among community-dwelling stroke-free population in Ghana and Nigeria. Data for 4267 community-dwelling stroke-free controls subjects in the Stroke Investigative Research and Education Network (SIREN) study in Nigeria and Ghana were used. Participants were comprehensively assessed for sociodemographic, lifestyle and metabolic factors using standard methods. Hypertension was defined as a previous diagnosis by a health professional or use of an anti-hypertensive drug or mean systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. Logistic regression analysis was used to estimate adjusted odds ratios (aOR) of hypertension and their 95% confidence intervals (CI) at p < .05. Overall, 56.7% of the participants were hypertensive with a higher proportion among respondents aged ≥60 years (53.0%). Factors including physical inactivity (aOR: 9.09; 95% CI: 4.03 to 20.53, p < .0001), diabetes (aOR: 2.70; CI: 1.91 to 3.82, p < .0001), being ≥60 years (aOR: 2.22; 95% CI: 1.78 to 2.77, p < .0001), and family history of CVD (aOR 2.02; CI: 1.59 to 2.56, p < .0001) were associated with increased aOR of hypertension. Lifestyle factors were associated with hypertension in the current population of community-dwelling stroke-free controls in west Africa. Community-oriented interventions to address sedentary lifestyles may benefit this population and reduce/prevent hypertension and stroke among them.