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 7,617 respondents (NCT users: 41 vs. non-NCT: 7576) from the Stroke Investigation Research and Educational Network 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 CT/MRI. Multivariable-adjusted logistic regression was applied to estimate the odds ratio (OR) and 95% confidence interval (CI) for the relationship between NCT and stroke at p<0.05. RESULTS: Out of the 41 (0.54%) who reported NCT use, 27 (65.9%) reported using smokeless NCT. NCT users were older than non-smokers (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 to promote evidence-based recommendations for public health prevention and management of stroke on the African continent.

Are there differences in perceptions, preferences and attitudes towards disclosure of genetic testing for Stroke? A qualitative study among stroke-free SIREN-SIBS genomics study participants.

OBJECTIVE: This study explored perceptions, preferences and attitudes towards disclosure of genetic testing results for stroke among stroke-free controls (and their family members) in the SIREN-SIBS Genomics Study, healthcare providers and policymakers. MATERIALS AND METHODS: We conducted a qualitative thematic analysis of key informant interviews with 61 participants recruited from community advisory boards (30) and health care providers (31) across seven sites in Nigeria and Ghana. RESULTS: Major findings illustrate differences in the knowledge of genetic testing with superior knowledge among health care professionals. Relatives and religious leaders were opined as the best to receive the disclosure as they would be able to break the news to the patient in a culturally sensitive manner to reduce the likely resultant emotional outburst. Poor level of awareness of national guidelines for disclosing genetic results exist. Key facilitating factors for disclosure are education, enabling environment, involvement of religious and community leaders, campaigns, and possible treatment options. Disclosure inhibitors include inadequate information, fear of marital break-up or family displacement, fear of stigmatization, fear of isolation, religious beliefs, health worker attitude, and lack of preparedness to accept results. CONCLUSIONS: These necessitate culturally sensitive interventions for continuing education, increased awareness and sustained engagement to equip all stakeholders in genetic testing disclosure process.

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 (ß) 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.