Prevalence of Acute Neurologic Insults: A Case for Going Global*
In the past, single country studies have tried to ascertain the burden of neurologic disorders in adults and children using various study designs (1, 3). Distinctively, the PANGEA study employs the model of point prevalence design to make estimates of disease burden (2).This study design has been recently applied to research in critical care with good results (4).This design has several advantages that make it particularly suitable for international epidemiological data collection. Some of these advantages are a-priori case definitions and better case ascertainment, ease of enrollment of patients across the globe, ease of conduct, less resource intensive, and less stringent consent requirements. But there are also limitations of this study design. This design can be hypothesis generating but cannot provide causality data. Second, it underestimates the burden of rapidly fatal diseases, which is especially relevant for research in critical care (5). Additionally, the most of the prevalence figures in surveys depend on the denominator being used. Of note is the fact that the patients admitted to PICU may vary widely across the globe. The reasons could be related to policy or logistic like criteria for age, surgical versus medical ICU, nonavailability of ICU beds, nonavailability of neurosurgical support, etc. In our own center, the PICU caters for children up to 14 years old (excluding neonates), and there are separate neonatal, pediatric surgery, neurosurgery, and trauma ICU’s. One can easily see the problems in comparing data from different centers when the denominator can vary. Some other important caveats need to be kept in mind while interpreting the PANGEA study results and while planning future studies. First, major bulk of the neurologic mortality and morbidity occur in children in a resource-limited setting. Unfortunately, this group of children does not find adequate representation in the study. This is important as both the nature of insults and quality of care differs considerably across nations.