Measuring the impact of stroke in Sierra Leone through stroke register methodology

Stroke is the second leading cause of death in the world. Presently, the majority of stroke deaths occur in low and middle income countries (LMICs). This research aims to understand stroke in Sierra Leone. Estimates suggest that Sierra Leone has the eighth highest burden of stroke in the world. However, there has been very little research to investigate the real burden and impact of stroke in Sierra Leone.
In high income countries, stroke registers have been important tools to provide the data to understand stroke as a disease, inform policy and guide the design of stroke services. Stroke registers have documented and driven great improvements in the quality of stroke care and the outcomes after stroke in high income countries. Stroke registers are a potentially potent tool to understand and tackle the estimated high burden of stroke in LMICs. However, further research is needed to understand how best to design stroke registers in low resource settings and how accurate and representative the data they provide is. In Sierra Leone access to health care is limited and therefore not everyone with stroke presents to a government hospital. Additionally, hospital data systems are under developed and cause of death registration is limited. This poses challenges to the design of stroke registers.
This fellowship will review stroke register methods used in Sub Saharan Africa. It will assess the quality of methods used and summarise the resulting data. This fellowship will analyse data from a stroke register in Sierra Leone to describe who is suffering from stroke in Freetown, Sierra Leone. It will explore what types of strokes are occurring and what the major risk factors are. The research will assess outcomes after stroke, to understand disability and health related quality of life (HRQL) of stroke patients at 90 days and one year post stroke.
The impact of stroke on individuals will be examined by researching HRQL after stroke. I will validate a HRQL questionnaire in the local language Krio. Patients are followed up immediately after stroke, 90 days post stroke and one year post stroke. I will examine whether HRQL after stroke can be predicted by patient level information such as age and gender, as well as disease specific information such as functional ability or stroke type and severity. I will employ an 'equivalence' framework to test and validate the translation of the HRQL questionnaire, which assumes that concepts of health and quality of life differ across cultures. It takes into account these differences and allows for more locally meaningful translation. I will explore new methods of applying the equivalence framework to HRQL questionnaire translation and further develop application of this translation/adaptation theory.
In low resource settings, many people with stroke may not be able to access hospital based care. The final component of the research will try to understand how representative hospital based disease registers are for the general population. The project will assess whether the hospital stroke register captures all the strokes occurring in Freetown and therefore how complete the register is. It will attempt to understand which people with which types of stroke do not present to hospital and therefore are not captured by a hospital based register.
The research will provide high quality data for the first time on stroke in Sierra Leone, demonstrating who is having stroke, what type of strokes are occurring and the major risk factors. It will demonstrate the impact of stroke on HRQL for patients over time. The validation of the HRQL questionnaire will support future researchers to undertake health and economic evaluations in Sierra Leone. Finally, the project will contribute to our understanding of the completeness and the interpretation of data from hospital-based disease registries.

I plan the following four part structure for my PhD: (1) Systematic review (2) Analysis of register data (3) Assessment of HRQL after stroke (4) Assessment of completeness of register case ascertainment.
1. The design, composition and completeness of stroke registers in Sub Saharan Africa- a systematic review
Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the review will synthesise the design, composition and completeness of registers in Sub Saharan Africa.
2. What are the impacts of demographics and stroke type on the outcomes for stroke in Sierra Leone: an analysis of a prospective hospital-based stroke register
Prospective hospital-based stroke register including all stroke types, that meet WHO definition of stroke. Multivariate analysis will be performed to determine odds ratios (e.g. age, gender, educational level, stroke type) for poor outcome at 90 days and one year after stroke.
3. What is the quality of life after Stroke?
HRQL data from the EQ-5D-3L and survival data immediately after stroke, at 3 months and 12 months will be utilised to calculate QALYs for stroke patients. Multivariate regression analysis will examine associations of patient characteristics (gender, age, educational level), stroke severity, stroke type and functional status with health utility scores at admission and QALYs at 3 months and 12 months. Sensitivity analysis will consider the impact of alternative strategies for replacing missing data.
4. Assessing completeness and co-variates for selection bias in a hospital-based stroke register
I will examine and compare descriptive statistics of three stroke datasets including demographics, stroke type and outcomes. Relative odds ratios for key variables across datasets will highlight which co-variates are involved in selection bias. Capture-recapture techniques will estimate completeness of case ascertainment.