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.

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 (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.

Mammographic Parenchymal Patterns in Asymptomatic Women.

BACKGROUND: Breast density has been found to be an independent risk factor for breast cancer. Mammographic breast parenchymal pattern or percent density is mainly a reflection of the proportion of glandular tissue to fatty tissue, and studies have shown that it works synergistically with other risk factors such as nulliparity in predicting breast cancer risk. This study analyses the various mammographic breast patterns and correlates this with some demographic variables and final Breast Imaging Reporting and Data System outcomes of asymptomatic women in our center. MATERIALS AND METHODS: This is a prospective descriptive study of mammographic breast pattern in 459 females who presented at the breast imaging suite of our institution. Mammography was performed after completion of an assisted administered questionnaire for demographic information. A GE Senographe DMR machine using two standard views (craniocaudal and mediolateral oblique) and additional views were used when necessary. RESULTS: A total of 459 women ranging in age from 34 to 80 years were included in the study, of which 46.6% were in the age range of 41 to 50 years. The scattered fibroglandular pattern was the most common pattern found (44%), and the homogeneous dense pattern was the least common (0.4%). A significant association with age and menopause status was found, while no association was found with age at the time of the woman's first delivery and family history of breast cancer. CONCLUSION: This study demonstrates that there is a significant association between breast cancer and age and menopause status. However, no correlation was found with the age of women at their first delivery and family history of breast cancer.

Posterior urethral valve with unilateral vesicoureteral reflux and patent urachus: A rare combination of urinary tract anomaliess.

Posterior urethral valve (PUV) is a common cause of lower urinary tract obstruction in male infants with an incidence of 1:5000-8000. PUV continues to be a significant cause of morbidity and ongoing renal damage in infants and children. It can coexist with vesicoureteral reflux (VUR) in about 50% of cases and also with patent urachus in about one-third of cases. It is a case of a 22-day-old full-term male child who presented with poor urinary stream and progressive abdominal distension of 5-day duration as well as leakage of clear fluid from umbilicus of 1-day duration. Abdominopelvic ultrasonography showed bilateral hydronephrosis. Micturating cystourethrogram also showed features of bladder outlet obstruction and PUV. In addition, a grade V left VUR and a fistulous tract between the dome of the urinary bladder and the umbilicus, which was consistent with a patent urachus was demonstrated. In conclusion, this case demonstrates a rare combination of congenital urinary tract anomalies involving PUV, left VUR and patent urachus.

Longitudinal evaluation of foetal transverse lie using ultrasonography.

The purpose of this study was to assess the risk of persistence of transverse lie detected earlier in pregnancy and associated predisposing factors using follow-up ultrasound (US). A longitudinal study was carried out from January 2004 to august 2004 at Federal Medical centre, Lokoja, Nigeria. All singleton pregnancies, with ultrasound diagnosis of transverse lie, between 24-28 weeks were followed to term. At 24-28 weeks, 183 fetuses presented with transverse lie. Thirty seven were lost to follow-up; out of the remaining 146 babies, 22 persisted to term. Overall persistence rate was 15.1%. No identifiable predisposing factors were seen in 91.1%, placenta previa in 5.5%, lower segment fibroids in 2.7%, and ectopic kidney in 0.7%. In conclusion, transverse lie detected early in pregnancy is transient, and majority would convert to a longitudinal lie at term. Potential predisposing factors highlighted above increases the risk of persistent transverse lie at term, with placenta previa and lower segment fibroids being the major predisposing factors.