Methodological Difficulties in the Conduct of Neuroepidemiological Studies in Low- and Middle-Income Countries

Abstract

Background: 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.

The impact of imperfect screening tools on measuring the prevalence of epilepsy and headaches in Burkina Faso

“…Second, verification bias and misclassification error can be addressed simultaneously by including an additional level in the Bayesian model estimating the specificity and sensitivity of the invalid test(s). The capture-recapture method is an alternative approach for obtaining corrected prevalence estimates [13]. This method combines multiple sources of information independently, such as medical records and non-medical interviews with community members, with the two-step approach.…”

“…Rural community-based studies in SSA often use a two-step approach to identify neurological disorder cases for prevalence estimates [13,14]. In step one, a screening test, often in the form of a questionnaire, is used to identify positive cases for the neurological disorder(s) of interest in the study population.…”

“…In step two, a physician or sometimes a neurologist confirms the given neurological disorder(s) through a medical examination, often only among those screened positive [15–19]. Diagnosis through electroencephalography is often not possible in rural community-based settings due to limited resources [13], and therefore, the physician/neurologist’s diagnostic is often considered as the gold standard.…”

Evolution of epilepsy prevalence and incidence in a Tanzanian area endemic for onchocerciasis and the potential impact of community-directed treatment with ivermectin: a cross-sectional study and comparison over 28 years

“…The gold standard in neuroepidemiological surveys to identify epilepsy cases in LMICs, the door-to-door approach, will be applied. 48 All inhabitants of the selected villages will be eligible for participation and will be included in the questionnaire screening survey. Due to well-described limitations of questionnaire studies on epilepsy (stigma leading to concealment of cases, recall bias, absence of clear terminology for epilepsy and seizures) and to increase sensitivity of case ascertainment, key informants who are likely to be aware of persons with epilepsy in the village will additionally be consulted.…”

Epidemiology of febrile seizures and epilepsy: a call for action

“…Performing a well-conducted study requires several features that are not easily reachable under all circumstances. Bharucha et al 19 raised methodological difficulties in the conduction of epidemiological studies in LMICs. To specify, LMICs face regulatory issues and lack of infrastructure (lack of census data, lack of a welldeveloped healthcare system, etc.…”