Stroke in Sierra Leone: Case fatality rate and functional outcome after stroke in Freetown

Background: There is limited information on long term outcomes after stroke in Sub-Saharan Africa (SSA). Current estimates of case fatality rate (CFR) in SSA are based on small sample sizes with varying study design and report high heterogeneity. Aims: We report CFR and functional outcomes from a large, prospective, longitudinal cohort of stroke patients in Sierra Leone and describe factors associated with mortality and functional outcome. Methods: A prospective longitudinal stroke register was established at both adult tertiary government hospitals in Freetown, Sierra Leone. It recruited all patients ≥18 years with stroke, using the World Health Organization definition, from May 2019 until October 2021. To reduce selection bias onto the register all investigations were paid by the funder and outreach conducted to raise awareness of the study. Sociodemographic data, National Institute of Health Stroke Scale (NIHSS) and Barthel Index (BI) was collected on all patients on admission, at seven days, 90 days, one year and two years post stroke. Cox proportional-hazards models were constructed to identify factors associated with all-cause mortality. A binomial logistic regression model reports odds ratio (OR) for functional independence at one year. Results: 986 patients with stroke were included, of which 847 (85.9%) received neuroimaging. Follow up rate was 81.5% at one year, missing item data was <1% for most variables. Stroke cases were equally split by sex and mean age was 58.9 (SD: 14.0) years. 625 (63%) were ischaemic, 206 (21%) primary intracerebral haemorrhage, 25 (3%) subarachnoid haemorrhage and 130 (13%) were of undetermined stroke type. Median NIHSS was 16 (9-24). CFR at 30 days, 90 days, 1 year and 2 years was 37.1%, 44.4%, 49.7% and 53.2% respectively. Factors associated with increased fatality were male sex HR:1.28 (1.05-1.56), previous stroke HR:1.34 (1.04-1.71), atrial fibrillation HR:1.58(1.06-2.34), subarachnoid haemorrhage HR:2.31 (1.40-3.81), undetermined stroke type HR: 3.18(2.44-4.14) and in-hospital complications HR: 1.65 (1.36-1.98). 93% of patients were completely independent prior to their stroke, declining to 19% at one year after stroke. Functional improvement was most likely to occur between 7 and 90-days post stroke with 35% patients improving, and 13% improving between 90 days to one year. Increasing age OR: 0.97(0.95-0.99), previous stroke OR: 0.50 (0.26-0.98), NIHSS OR 0.89 (0.86-0.91), undetermined stroke type OR:0.18 (0.05-0.62) and ≥1 in hospital complication OR:0.52 (0.34-0.80) were associated with lower OR of functional independence at one year. Whilst hypertension OR:1.98 (1.14-3.44) and being the primary breadwinner of the household OR:1.59 (1.01-2.49) were associated with functional independence. Discussion: Stroke in Sierra Leone affected younger people, and resulted in high rates of fatality and functional impairment relative to global averages. Key clinical priorities for reducing fatality include preventing stroke-related complications through evidence-based stroke care; improved detection and management of atrial fibrillation, and increasing coverage of secondary prevention. Further research into care pathways and interventions to encourage care seeking for less severe strokes should be prioritized. Data availability: Requests for access to anonymized data for academic use should be made to the SISLE team https://www.kcl.ac.uk/research/stroke

The feasibility, repeatability, validity and responsiveness of the EQ-5D-3L in Krio for patients with stroke in Sierra Leone

Objectives: To assess the feasibility, repeatability, validity and responsiveness of the EQ-5D-3L in Krio for patients with stroke in Sierra Leone, the first psychometric assessment of the EQ-5D-3L to be conducted in patients with stroke in Sub Saharan Africa. Methods: A prospective stroke register at two tertiary government hospitals recruited all patients with the WHO definition of stroke and followed patients up at seven days, 90 days and one year post stroke. The newly translated EQ-5D-3L, Barthel Index (BI), modified Rankin Scale (mRS) and National Institute of Health Stroke Scale (NIHSS), a measure of stroke severity, were collected by trained researchers, face to face during admission and via phone at follow up. Feasibility was assessed by completion rate and proportion of floor/ceiling effects. Internal consistency was assessed by inter item correlations (IIC) and Cronbach’s alpha. Repeatability of the EQ-5D-3L was examined using test–retest, EQ-5D-3L utility scores at 90 days were compared to EQ-5D-3L utility scores at one year in the same individuals, whose Barthel Index had remained within the minimally clinical important difference. Known group validity was assessed by stroke severity. Convergent validity was assessed against the BI, using Spearman’s rho. Responsiveness was assessed in patients whose BI improved or deteriorated from seven to 90 days. Sensitivity analyses were conducted using the UK and Zimbabwe value sets, to evaluate the effect of value set, in a subgroup of patients with no formal education to evaluate the influence of patient educational attainment, and using the mRS instead of the BI to evaluate the influence of utilising an alternative functional scale. Results: The EQ-5D-3L was completed in 373/460 (81.1%), 360/367 (98.1%) and 299/308 (97.1%) eligible patients at seven days, 90 days and one year post stroke. Missing item data was low overall, but was highest in the anxiety/depression dimension 1.3% (5/373). Alpha was 0.81, 0.88 and 0.86 at seven days, 90 days and one year post stroke and IIC were within pre-specified ranges. Repeatability of the EQ-5D-3L was moderate to poor, weighted Kappa 0.23–0.49. EQ-5D-3L utility was significantly associated with stroke severity at all timepoints. Convergent validity with BI was strong overall and for shared subscales. EQ-5D-3L was moderately responsive to both improvement Cohen’s D 0.55 (95% CI:0.15—0.94) and deterioration 0.92 (95% CI:0.29—1.55). Completion rates were similar in patients with no formal education 148/185 (80.0%) vs those with any formal education 225/275 (81.8%), and known group validity for stroke severity in patients with no formal education was strong. Using the Zimbabwe value set instead of the UK value set, and using the mRS instead of the BI did not change the direction or significance of results. Conclusions: The EQ-5D-3L for stroke in Sierra Leone was feasible, and responsive including in patients with no formal education. However, repeatability was moderate to poor, which may be due to the study design, but should add a degree of caution in the analysis of repeated measures of EQ-5D-3L over time in this population. Known group validity and convergent validity with BI and mRS were strong. Further research should assess the EQ-5D in the general population, examine test–retest reliability over a shorter time period and assess the acceptability and validity of the anxiety/depression dimension against other validated mental health instruments. Development of an EQ-5D value set for West Africa should be a research priority.</p