Methodological Difficulties in the Conduct of Neuroepidemiological Studies in Low- and Middle-Income Countries
Résumé
The majority of people with epilepsy (PWE) live in low- and middle-income countries (LMICs). However, they remain largely untreated and the bulk of resources are used to treat patients in the developed world. This disparity constitutes a challenge for neuroepidemiological studies on a global scale. In the past, several studies have focused on diverse populations in disparate countries at various periods of time and for particular purposes. The specificity of different contexts and circumstances makes it difficult to analyse PWE as a group either qualitatively or quantitatively. Such methodological limitations are further complicated by a lack of logistical support. There is a lack of interest in conducting studies, which results in inadequate funding and, in addition, there is the considerable challenge of publishing research reports from LMICs in peer-reviewed international journals. Methods: This paper focuses on methodological problems related to studies in LMICs and attempts to give the reasons for their limitations using epilepsy as an example. Results: Regional conditions and environmental factors must be given careful consideration in the research design because of the importance of understanding the challenges of living in these environments. There are further limitations to the successful implementation of studies. Existing information on epilepsy is often not readily accessible; there is a lack of census data, and migratory patterns into cities make enumeration and sampling even more challenging. As there is usually no well-developed healthcare system a door-to-door screening process is often the only way to identify those with convulsive epilepsy. The questionnaire and study design should preferably be adapted from standardized protocols, and pre-tested and validated in local conditions. Conclusions: Systematic reviews and meta-analyses of studies in LMICs can provide data on the burden, risk factors, treatment and outcome of epilepsy only if the primary studies used are properly conducted using uniform and comparable methodology. The use of consistent replicable neuroepidemiological methods in primary studies and systematic reviews enable reduction of the treatment gap and better epilepsy care.