Results from the IRIS Systematic Review of Methylmercury: Developmental Neurotoxicity (DNT) Outcomes Evaluated in the Literature
This poster presents results of the systematic review conducted to support the Methylmercury IRIS Assessment, which is focused on developmental neurotoxicity (DNT). The first step of the systematic review was a literature search (1998-February 2022) to identify studies on health effects of methylmercury exposure, utilizing four databases (PubMed, Web of Science, TOXLINE, ScienceDirect), which identified >17,000 studies. Influential studies from the 2001 IRIS Methylmercury Assessment were also included. SWIFT-Review and DistillerSR were used to screen studies, which resulted in identification of approximately 350 epidemiology studies reporting quantitative data for methylmercury DNT. These studies underwent study evaluation to assess study sensitivity, and risk of bias for the following domains: exposure measurement, outcome ascertainment, participant selection, potential confounding, analysis, and selective reporting. These domain-specific evaluations were considered together to arrive at an overall study confidence classification. Approximately 70 published studies (including re-analyses) received medium or high confidence ratings and reported quantitative data useable for dose-response analysis.
Noting some overlap in domains, DNT outcomes in the identified studies were categorized as follows: omnibus general intelligence/IQ, omnibus developmental, academic achievement; clinical conditions; or domain-specific [attention, executive function, motor function, learning and memory, processing speed, social-emotional, verbal/language, and visuospatial/fluid reasoning], and other outcomes, for example, electrophysiologic and audiologic. The poster will present details on the number of times that each outcome was evaluated and the instruments used to do so.
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